I live in CT and currently have an oil boiler that provides DHW and heats the home via copper baseboard pipes (hydronic). With oil prices shooting up, I am fed up. My oil burner was installed with the home in 1994 and is very inefficient. I resorted to heating 2 of the 3 zones during the winter to keep the oil consumption down. What options do I have for getting rid of oil and splitting my DHW off into an electric water heater w/tank and keeping the hydronic baseboard heat? Natural gas is not an option unfortunately. My budget is $10,000 not including any federal and state credits/rebates. I have requested a quote from a local HVAC company for a geothermal system knowing full well it will not fit into my budget, but I'm just curious at this point. The biggest problem I'm having is finding reputable installers. It's easy to find installers for oil boilers, but for the environmentally friendly stuff it's a crap shoot. I have even entertained a wood boiler. Any of my options would need to be installed by a professional as I'm not a DIYer.

How much oil/year are you currently using, and how big is your house?

To get a handle on your actual vs. rated AFUE, down load and carefully check with the NORA FSA Calculator downloadable here:

http://nora-oilheat.org/site20/fsa/FSACalculator_1_1_0_8.zip

the manual for the software lives here:

http://www.nora-oilheat.org/site20/uploads/copier@eeacompanies%20com_20110111_150909.pdf

If yours is like most homes, you can get a significant bang/buck out of a round of air-sealing (with calibrated blower-door test & verification), and spot-insulation (with infra-red camera testing & verification). There are likely subsidies to be reaped from the state & feds for any upgrading. If your basement, foundation sill & band joist aren't insulated, foam sealing the sill & joist and insulating the basement walls would likely result in a 15-20% fuel savings-sometimes more. (Careful how that's done- you don't want to create moisture or mold problems by driving ground moisture higher in the insulation or any interior studwall or allowing wintertime condensation to form. See: http://www.buildingscience.com/documents/information-sheets/5-thermal-control/basement-insulation/files/bscinfo_511_basement_insulation.pdf )

Only with all the low-hanging fruit is thoroughly plucked clean would spending money on a full heating system swap make sense, and the size & cost of any new system would be significantly reduced by the now-lowered peak heat load. If you spent half the money on weatherizition and insulation upgrades you MIGHT be able to spend the rest on a tank-based condensing propane combi boiler for both heat & hot water, but you're right, you won't be able to touch even half of a geo system for $10K. Unless the oil boiler is on it's last legs upgrading the envelope and re-commissioning the boiler (maybe with indirect fired hot water, or reverse-indirect buffer/hw heater replacing the lo-efficiency embedded coil- see: http://www.nora-oilheat.org/site20/uploads/FullReportBrookhavenEfficiencyTest.pdf ) might be the right course.

With a buffer tank or reverse-indirect and re-plumbing the heating system primary/secondary you can then slave the boiler to the buffer's aquastat and run the baseboard at lower temp than would otherwise be "safe" for the boiler, and with the mass of the buffer the boiler

A: can be heat-purged into the buffer at the end of a burn with a retrofit controller like an Intellicon HW+ or Beckett Heat Manager for lower standby loss, and

B: Won't "short cycle" with the extra thermal mass of the tank to work with. This would take a competent hydronic designer to work out the details, but with this sort of approach most circa 1994 vintage oil boilers can be made to run at 85% efficiency despite being oversized for the load. If yours is 3x oversized fro the peak load (probably is) it's likely to be running somewhere in the low 70s, for AFUE (maybe lower if you're keeping it at 140F all summer just for hot water), and bumping it up to 85% operation would mean a 20% reduction in fuel use.

If it costs you $5K to re-configure the system to allow lower temp operation (it should be less) for a 20% reduction, and another $5K in insulation upgrades buys you another 20% you're looking at a total net reduction in fuel use of ~36%. (If the boiler craps out on you, replacing it with a "right sized" propane fired cast iron or low-mass copper fin low temp boiler would be cheap relative to a modulating/condensing version, and could be a relatively simple swap. If your baseboards can deliver design-day heat at 120F it's probably worth buying a mod-con though.

For the price of a 4 ton geo system you could probably do a deep energy retrofit on the building envelope and reduce the fuel use by 60-70%. See:

https://www.powerofaction.com/media/pdf/DER_CaseStudy_Belchertown_MA.pdf

https://www.powerofaction.com/media/pdf/DER_CaseStudy_Millbury_MA.pdf

https://www.powerofaction.com/der/

Got a zip code? (For weather data against which to correlate fuel use to get a good handle on the sizing requirements.)

OK so your basic question is what are your options for a new heating system. Dana has the right approach, reduce demand, then worry about the heating system.

Step #1 is get an energy audit. Go to CL and P or united illuminating and sign up for an energy audit and weatherization. It will cost you 75$ Best deal in town. Included in that should be an assessment of your existing boiler efficiency. Includes a baseline blower door test.
Step 2. Once the house has whatever weatherization upgrades can be done reasonably and quickly as part of the audit package, then you have a reasonable basis for what to do next.
Step 3 Priority #1 is usually building shell upgrades, guided by the audit. After that, then you can think about what the heating system can/should be. Have a blower door test done after the final shell upgrades so you have an accurate # on infiltration.
Step 4. Have the contractors do a manual J calculation for the house using updated numbers for the shell upgrades. Make sure to include infiltration numbers from the blower door test. Also calculate how much baseboard you have and what water temp you need to supply enough heat at design temp.
Your choices for heat are:
1. OIL, either condensing or other
2. propane mod con or standard
3. electric resistance boiler,
4. GSHP, and air source heat pump,
5. wood boiler or pellet stove
6. A combination of the above.
It is a lot to think about. Connecticut has high cost heat, no matter how you get it. Electricity is expensive, heating oil is expensive, propane is expensive. In this state especially, the key to lower bills is an aggressive insulation and airsealing strategy.
Oh and don’t be so quick to jump on installing an electric hot water heater. This is not likely to help much vs a good indirect tank.
When you get the audit, airsealing and insulation done get back to us and we can help you further on boiler upgrades or replacements.

Good luck, it is a worthwhile endeavor but it takes time and thought to get the best bang for the buck.

Cheers,
Eric

Dana1, I will definitely try that calculator out tonight.

Eric, I plan to go for a loan from CTEnergyLoan.com which requires I get an audit from CL&P. I know they try to get out of doing the blower test, but I will demand it. For $75 this is a no brainer. The only question I have about this is that I use Green Power Inc and not CL&P directly (they still deliver the electricity) and am not sure if that disqualifies me for the $75 audit and eligibility for the CT Energy Loan. Technically I am still a CL&P customer since it is them that I would call for any issues with my power.

Some details about my house:

-zipcode 06706
-The house is nearly 17 years old
-1670 sq. ft., three floors/zones which is including basement
-The basement is finished and insulated
-I've already got double pane windows
-2.5 bathrooms

One of my goals is to be able to turn off the home heating boiler during the summer. As it stands right now, I obviously have to leave my oil burner running during the summer for the DHW. With a filled oil tank from May 1st and all heating zones shut off, I use about 3/4 of a tank from May 1st to late October when the next fill-up occurs. I would love to keep a full tank from May 1st until the following cold season.

I have toyed with the idea of getting a tankless electric hot water (on demand) heater for all DHW. Does anyone in the north east have any experience with one of these? Do you recommend it? Right now I am leaning towards an electric WH with tank, or an indirect WH. If I plan to turn off the boiler during the warm months, I have to go with a water heater that uses another heat source and can't use an indirect WH, correct?

Can anyone recommend a good site for finding reputable HVAC contractors?

Thanks for the replies!

OK so lets get down to some numbers. These are just educated guesses based on limited info. (and my math is always sketchy anyway)
¾ of a 270 gal oil tank is ~202 gallons of oil. At 100% efficiency that would be 202 X138,000 btu = 27.8 Million btu’s used for DHW in 7 months.
The realistic efficiency of the boiler in this mode depends on a lot of things, but lets use 50% in summer mode. Without more details about the system, you can’t give too good an estimate for this. If we said net usage of energy for hot water was 14 Million btu’s for 7 months that gives ~24 million btu’s of hot water usage per year, 2 million/month if we assume incoming water is 55° and water is used at 115° the delta is 60° so to heat 1 gallon takes 60°* 8 lbs/gallon= 480 btu/s. 2,000,000 btu’s/month/ 480 btu’s per gallon = ~ 4200 gallons of hot water per month,or 140 gallons per day. For a family of 4, 140gallons per day is not too bad, if you are single, it sucks.
Obvius things to check. Get a 5 gallon bucket and time how long it takes the shower to fill the bucket. You can get down to around 2 gpm shower head and still have a good shower. Bathroom sink aerators should be around 1 gpm. Kitchen sinks ballpark 2.5 gpm. Newer dishwashers use much less water then old ones, same with washing machines.

As far as costs go assume point of use electrical water heaters have 100% efficiency, tank type ones 80% (ballpark based on usage, standby losses, length of pipe in between heater and usage).
1 kwh = 3412 btu electricity ~0.17$ kwh here in CT
If you used electricity to generate the hot water, it would be 2,000,000/3412= 586 kwh/ month at 100 % efficiency or 100$ per month in hot water usage with tankless point of use, probably 125$/month with a electric water tank.
Oil uses 4,000,000 btu’s per month at 50% efficiency. 4,000,000 /138,000= 28 gallons per month *4.50$ gallon = 130$ per month.
Again, your best bang for the buck is probably an indirect tank from the boiler, configured the way Dana indicated, along with reducing hot water usage.
Oh and don’t read too much into the back of the envelope calcs I made above, we don’t have much information to go by.

Other questions?
How many gallons per year of oil do you use?
How many people living in the house?
How much electricity do you use per year, per month average, and in Jan, Sept, and July.

Cheers,
Eric

I you use an indirect + heat-purging control you can set up the boiler for cold-starting rather than maintaining temp in the boiler all summer (or during the shoulder seasons.) Operated this way your summertime fuel use would drop by half or more. With the right control scheme you can safely repeatedly cold-start standard oil boilers without corrosive condensation when running an indirect because the coil of the indirect pre-heats the boiler using the thermal mass of the indirect, shortening the time period when it's operating below temp. (Some boilers of the 1990s were designed to be cold-start tolerant on their own, but when using the tankless coil you had to keep the boiler at temp anyway.)

You can run an electric tankless in series with the output of the indirect if you plan to simply turn off the boiler during the summer. When the incoming water temp at the electric tankless at or above it's setpoint the tankless uses no power, so when the indirect & boiler are operating the power used by the tankless would be nil. A 20KW tankless might be enough to run the shower and one other smaller load simultaneously during the summer, but probably not in winter with your incoming water temps. But the cost of the electric upgrades for installing a tankless might be a bit daunting- you're looking at a dedicated 100amp 240volt service drop for the just the tankless.

Without knowing your tank size there's no way to assess what your annual or summertime fuel use is, but with an indirect it would be cut in half. If you're the showering type (as opposed to a tub-bathing) family, installing a drainwater heat recovery system down stream of the main shower as pre-heat for both the cold-feed to the shower & water heater (whatever type you use.) It takes at least 4 feed of 4 inch, or 5 feet of 3 inch vertical drain pipe down stream of the shower to get ~50%+ return out of a drainwater heat recovery system. (Fatter & taller == higher return.) For showering families this is typically good for a 20-25% reduction in water heating fuel use. For a comparative list of models/by performance see: http://oee.nrcan.gc.ca/residential/personal/retrofit-homes/drain.cfm?attr=4

The US distributor for Power Pipe is EFI, who will set up an account and sell wholesale-direct in onesie twosies over the phone with a credit card: http://oee.nrcan.gc.ca/residential/personal/retrofit-homes/drain.cfm?attr=4

Note: Some local inspectors have an issue with the ASTM ratings of sub-components of PowerPipe (who uses a heavier stock for one part than falls under the more general potable water ASTM mark), so it might be a good idea to pre-approve the model with the locals before installing it at your house. Several states offer rebates for them, and have that vendor listed, but SFAIK not CT. (OR, MN, VT, WI etc.)

What are the input & DOE heating ratings of your existing boiler? Given the description of your house and the Waterbury location I'd expect your outside design temp to be in the +5-10F range, and design condition heat load to be on the order of 25-30KBTU/hour unless your infiltration rates are high. (DO have the place blower-door tested & IR imaged for fixing any gaps and you should be getting down there or even lower for short money.) Even the smallest oil burners are 2x oversized for the whole house load and MANY times that of your smallest zones. If yours is rated 100,000BTU or higher you're at least 3x oversized, and operating on the cliffy end of the curves in the regression plots of the appendicies of the Brookhaven boiler analysis: http://www.nora-oilheat.org/site20/uploads/FullReportBrookhavenEfficiencyTest.pdf

Heat purging controls such as the Intellicon would almost certainly reap double-digit savings on oil use during the heating season as well, especially since you have it multi-zoned.

Lots of information here, it's hard to know where to start. When I get home tonight, I'll try to get as much of the requested information as I can. I do know that my oil tank is less than 275 gallons. It's more like ~175 gallons. I don't know what the actual capacity is because it is sealed away under a plaster type structure and all that I can see is the oil gauge. Thanks for the replies, I chose the right forum for my questions. I'm not familiar with some of the terms you are using since I have almost no HVAC knowledge.

Getting a gallons per year number and the boiler's BTU ratings are necessary for running FSA calculator tool.  If you know the model name/number we might be able to dig up the ratings from the web, but somewhere on the boiler there's a plate indicating it's input & output ratings that will say something like:

Input: 120,000BTU  (or it might be in MBH or gph)

Output: DOE heating capacity 103,000BTU  I/B/R water 93,000BTU

AFUE: 85%

or something similar.  It'll look something like this:

http://technivend.com/images/IM...5-0617.jpg

and may be on the outside, or inside a door/panel.

The FSA Calculator will also give you an estimated design heat load for weather if you use a gallons/year number and a location (Choose either Hartford or Bridgeport from their list.   On the equipment selection section choose "custom boiler", and use the numbers from the plate on the boiler.  The steady state efficiency to plug in will be output BTUs divided by input BTUs (in percent)

For yuks (and to remember the specifics of the tool) I ran one for 800 gallons/year of oil consumption for a house in Hartford, plugging in 86% efficiency with 100,000BTUs of heating capacity for the boiler, heating 64 gallons/day of domestic hot water.  The tool estimates that the design condition heat load (the coldest 1% of hours of the heating season) is ~25,500BTUs/hour, but the operating efficiency of the system is estimated to be 59% (due to the ~4x oversizing of the burner output to the amount of heat you actually need.) 

Dig through old billing or get the records from your fuel supplier, and using say 2-3 full years of use, figure out roughly how many gallons of oil you use in a year, then look up the numbers on the plate (or the model name & number) to figure out the rest.  If you have 3-4 people showering there every day 64 gallons of hot water use is the right ballpark, if it's 1-2 you might back that off to 45 gallons or lower to see how it affects the result.

If your boiler's specs are similiar (or higher) than the 100K output case I ran, you could see about a 25-30% reduction in annual fuel use by setting it up with a buffering reverse-indirect like a TurboMax or Ergomax, using a retrofit heat-purging controller on the boiler. If the boiler has only 60,000BTUs of heating capacity your efficiency jumps to ~68% (and the calculated heat load at design conditions is now recalculated to be ~30,000, if you used 800 gallons), in which case the fuel savings of a bufferd & heat-purge approach would be more on the order of 15-20%.  (IIRC 60,000 BTUs was about the smallest burner available for oil boilers in the '90s.  Smaller versions exist now, but not much smaller, and they often tend to have nozzle-clogging issues.)

The temp you'd have to set the reverse-indirect tank to depends on how much baseboard you have, etc, but odds are good you could run it at 130-140F year-round (set-it-and-forget-it), which is about where you'd want to set it for the summer.  But the configuration would look something like this schematically. http://www.ergomax.com/Radiant.jpg or this

I understand that you don't necessarily want to become a heating system designer, but you might have to be super-specific about your goals when dealing with the contractors/designers who reconfigure the system.  If you look at that Ergomax system schematic, note that the zone pumps draw exclusively from the reverse-indirect, and are completely independent of the boiler loop's pump.  The boiler's controls only "see" one zone- the buffer tank, and don't care whether it's one, three, or heat leaving via the tank's internal coil when somebody is showering that caused the tank to drop below it's setpoint, turning on the boiler.  If you use an Intellicon HW+  to sense the call for heat from the reverse-indirect, it "learns" the system, and turns off the burner on the boiler before turning off the boiler's pump to draw as much heat as it can from the hot boiler into the reverse-indirect.  If the boiler is thus "parked" at 130-140F at the end of each burn rather than 160-170F  it's standby losses are reduced dramatically.  Boilers are typically not well insulated, but indirects are, so the standby loss from the tank is much lower than the situation you'd have with a boiler maintained at 140F+ continuously (the summertime HW heating condition)  rather than parked at a lower temp at the end of a burn and allowed to cool off between burns.  The result is a net-boost to your as-operated system effiency, even if the boiler is way oversized for the amount of heat needed. 

If you needed 100% of the heat of an 86% efficient boiler 100% of the time you get 86% efficiency.  But with a 4x+ oversized boiler you never need more than 25% of it's output (except when showering, which is a tiny fraction of the time), and the average is less than 10% of it's output, which means it's spending the bulk of it's time in standby mode, and cycling on/off often with fixed-losses at every ignition cycle, which is what reduces it's efficiency to ~60%. By adding the reverse indirect you're reducing the number of cycles, since heat stored in the tank can be drawn even without involving the burner (and the thermal-mass of the tank is several times that of the boiler itself), and by using an Intellicon or Beckett control, you're cutting the boiler's standby losses by a large fraction.

FWIW: A small ErgoMax (model E23 or E24) or TurboMax reverse-indirect runs about $1100-1500 f.o.b. the distributor's warehouse (see http://www.bgmsupply.com/searchresults.asp?category_id=156 for an example) , an Intellicon or Beckett controller is a couple hundred (eg: http://www.patriot-supply.com/products/showitem.cfm/155940 ). You may be on the hook for another pump, depending on how the current system is plumbed & controlled, but the existing zones can probably use the existing controller with some minor wiring changes. The installation cost will vary depending on just how much space there is and how awkward it is, etc. but if you presented the "plan" to a few different heating & plumbing contractors and get quotes from those who seem to understand the concept without too much prompting on your part you should be able to get something reasonable installed for under $4K (maybe under $3K) if there's any competition in your market. The key might be find somebody who has experience designing & installing both reverse-indirects and economizer controlls. (You might find out from the manufacturer or distributor which contractors in your area have been buying their reverse-indirect HW heaters.)

A decent heating contractor would be able to tell you based on the heat-load number calculated by the FSA tool based on your fuel use with the existing system whether you have enough baseboard to deliver the heat at 130F or not. Even if they think it's a higher number, it doesn't hurt to turn it down to 140F, and only bump it 5F at a time if it doesn't stay warm enough on the very-cold days. The min-temp programmed into the Intellicon should be about 140F no matter what tank temp is set to, unless the boiler is a "cold start" type (which would be described in the manuals & literature for the boiler), but the installer/contractor should be able to explain that to you (rather than you explaining it to them.)

Unfortunately I can't get exact gallon amounts for the previous years until tomorrow when the oil supplier is open. I actually switched oil providers a year and a half after moving in so I only have 2 years of history that I can verify. This also means I can't use the calculator from Dana1's post until I can get the gallons I used, otherwise the calculator input values will be more guesswork than anything. I can only get payment histories back to April '09 from my bank website. I do know I spent $1753 on oil in 2010. That doesn't sound too bad, until I look at how much I've already spent in the first three months of 2011- $1380! And come May 1st, I will probably need another fill-up to the tune of $500-600.

Here is the information from my oil boiler:

Model: Columbia Emerald Series EM-100
Input BTU/Hr: 140000
DOE Capacity BTU/Hr: 11300 (~80% efficiency)
Net Rating BTU/Hr: 98000
Burner Type: Beckett
Burner Model: AFG

BTW, I've got the heating audit scheduled for next week!

10k might go a long way to cutting your consumption of fuel oil with an insulation company.
Geo is not going to get done for you with standard baseboards.
Start with envelope improvements, then ask local geo guys if they can make the numbers work for you.
j

Well I got my past two years of oil usage today and tried using those values in the FSA Calculator. It doesn't appear to work correctly based on my oil consumption. See the attached screenshot. Any suggestions? [edit]The image attachment system on here is a joke. Here is a link to the uncompressed image: http://i.imgur.com/8azAy.png

It's a buggy tool which sometimes need a re-start to clear things when you enter erroneous data.

It looks like you plugged in 70 o 78 for the steady state efficiency, which should be 81% (113k/140k), if your reading the rating plate is correct, or 84% otherwise. According to the literature the EM-100 has and output of 118K (not 113) an AFUE of 83, which means steady-state would be ~84% see:

http://columbiaboiler.com/residential/emerald/documents/EmeraldSeriesManual10.08.pdf

http://columbiaboiler.com/residential/emerald/documents/emerald_brochure.pdf

You seem to have used an idle loss of 4.1% which is probably high. For a post-1980 boiler- try something between 1 & 3.

Is the fuel use 640, 540, 580 or ??? (the .gif is pretty blocky and hard to tell exactly what was entered)

I know you say you're not fully heating each zone, but plugging in 640 gallons/year, then selecting "custom boiler", and editing in 84% steady state, idle loss of 3% it's coming up with a design condition heat load of ~ 14.3K (which seems too low), but plugging or if 2% it's ~ 18.5K which is still low, but not impossible if you're only heating part of the house to full temp and using setback thermostats, etc. Plugging in 1% idle loss it calculates ~20.2K, for a heat load, which is starting to feel credible based on experience assuming 1/3 of the house isn't being heated fully. It's probably somewhere in that ballpark between 1& 2. Let's call it 1.5 (still just a WAG.)

Using lower fuel usage numbers the calculated heat loss is even lower, implying either a very tight house with a very low amount of window area, or perhaps an additional heat source, or you're keeping the place at 50F or something. Do you supplement heat with any other source, like a woodstove or electric space heaters or ???

But it looks like with any of the numbers you're operating below 60%, and possibly below 50%, and configuring the system with a reverse-indirect as a system buffer (and configuring the boiler controls for cold-starting with an Intellicon HW+ in the control loop) would make a huge improvement in average efficiency- well into double-digits. The only time you ever need the full 118K of burner output is if you were taking an hour long shower in the dead of winter, but it would still keep up at your house, with a 26 gallon ErgoMax E23 set to 140F. You may have to set it a bit higher if your baseboard is truly minimal in length, but I doubt it.

The boiler has 13.5 gallons of water, the ErgoMax has 26, so you're about tripling the thermal mass of the system from a minimum burn length point of view. With the embedded coil set up per manufacturer's instructions it looks like the boiler stays at 160-180F(!) as recommended by the installation manual in that first .pdf- (see section C on page 4.) You're basically changing the operating mode to that of a non-tankless version and inserting the smart controls for the low-limit & circulator control. The standby loss of a boiler that hot is higher than need be, and with that much burner and your low heating loads you could easily tweak the low-limit on the existing setup down to 140-145F, keeping the high limit at 180F (to keep the min-burn rate in stand by reasonably long), and reap at least a 5% reduction in fuel use since it cuts the number of burn cycles about in half, and reduced the average operating temperature by ~10F.

Set up as per the manual in tankless mode the minimum burn time in summertime standby is only about 75-90 seconds, and the first 6-10 seconds are a fuel-lossy ignition cycle- you've blown something like 6-8% of the totalfuel for that burn even before the burner is fully up snuff which reduces the average efficiency. But by doubling the difference between high & low limits the burns are twice as long, and the time between burns is long is a bit longer than twice as long- long enough that standby-only burns may (mostly) go away, so you've cut that fixed loss per burn by more than half.

With an ErgoMax reverse-indirect buffering the system they WILL go away, despite only a ~7F high/low difference in it's aquastat, the standby loss at 140-145F would be about a half-degree per hour. Then the only time the burner kicks on in summer would be during/after some actual hot water use, and with the smart controls installed would park the boiler near the indirect's setpoint at the beginning of standby, some 30-40F below where it's currently left at the end of a burn. That 30-40F difference in beginning standby temp represents the heat of over a half-cup of oil-burn that was most likely to have been completely wasted in a summertime burn cycle, now safely stored inside an insulated tank rather than a (much lossier) boiler. A cup or two per day of wasted fuel adds up over the course of a summer. The rate of heat loss of the boiler into a 70F room going from 140F to 100F is substantially longer than from 180F to 140F, despite it being the same amount of temperature drop, so even though the boiler has to burn a bit longer to come back up to temp on a cold-start the total system standby loss has been cut by about half, raising the summertime efficiency from ~25% to ~50%.

The annual AFUE of such a system can be estimated using the FSA calculator by selecting "Purge Control 88% AFUE..." from the boiler pull down, and editing the efficiency down to 84%, and the idle loss first up to 1.5%, let it calculate, and re-adjust the heat load guess, then bump the idle loss down to 0.3 or 0.5. It looks like you'd be going from a 55-60% AFUE to a 70% or more- an minimum fuel savings would be ~15%, but 25% would be still in the realm of reality.

If you have the exact dates between two fill-ups this season we can look up the heating-degree data between those dates and calculate a K-factor (degree days/gallons) which might get us a bit closer to your actual heat load. eg: Say you filled up on 26 January, then again on 17 March, and the March fill was 178 gallons, and the http://www.degreedays.net/ daily tally between those dates adds up to 1187, the K-factor would be 1187/178=6.7 Using K-factor rather than a wild guess on annual fuel use you'd have to either round up to 7 or down to 6- the tool won't accept fractional-K, but it's probably more likely to deliver a realistic heat load and other numbers than the above analysis.

The EM-100 is a model they still sell, but the specs they list at the site do not exactly match what is on my boiler. I'm guessing they've made efficiency improvements over the last 17 years. As for your questions- 1.) I used 580 gallons for the calculator which is the higher of the past two years' oil consumption. The rest of the values I let the utility autofill based on the boiler I selected. Even with making the changes you recommended to the idle loss value, the program still warns me that the design day heat value is unusually low. 2.) I turned off the basement zone since even in the coldest months it never gets below 62F. 3.) I know there are "leaks" in my house as I can feel a slight draft coming from upstairs on cold days. So I know I can do much better with sealing/insulation. 4.) Do you have a link for reading up on the differences between an indirect vs. reverse-indirect system? I've got someone coming by to offer a quote on adding an indirect tank and he didn't really have any answers for me when I mentioned a reverse-indirect system. He did mention that with an indirect tank that the boiler would now have be able to run from a cold start instead of having to maintain the 140-180f temps that it does now. My current aquastat will be going away with this new system. 5.) I do have dates and exact amounts of the three fill-ups I've had since last fall. I did have the third zone running up until the end of January, so that is why my first fill-up of the year was so high. Nov-17: 140 gallons, Jan-17: 194 gallons, Mar-04: 160 gallons By the way, how the hell do you break your replies into paragraphs on this forum? Every time I post, it puts everything into one long rambling paragraph!

By the way, how the hell do you break your replies into paragraphs on this forum? Every time I post, it puts everything into one long rambling paragraph!

And you would be posting from a Mac??

No, Windows, but I am using Google Chrome. If I try to edit my post, the proper formatting is intact on that screen, it just doesn't carry over to when the post is submitted.

You need to put < b r > (without spaces) where you want a break.

I'd consider a heat pump water heater for use in the summer. There may be other optimizations if you have offpeak electricity rates.

The differences between reverse-indirect/indirect are a hydronic design problem related to output rates of your heating zones relative to the boiler output and the total mass of the zone+ boiler.  It really about buffered compared to unbuffered heating system (not reverse-indirect compared to indirect hot water) when the smaller zones aren't big enough deliver more than ~25% of the boiler's full output.  When that happens the boiler cycles way too often, giving up way much of it's fuel to ignition cycles and even more heat as standby loss.

Given that your whole-house heat load is but a fraction of the boiler's output to begin with, and you've chopped it up into even smaller zones, I'd be surprised if the heat load of smallest zone was even 10% of the boiler's continuous output, which means you either have to crank the temp up (so that the baseboards deliver heat at a faster rate) losing efficiency to distribution & standby, or let it short-cycle itself to low-efficiency on ignition cycles- it's a no-win situation.

The SOLUTION is to add thermal mass to the system in the form of an insulated tank, and let that thermal mass be involved in every burn cycle, stretching out the burns.  A reverse-indirect provides that mass, and that allows the baseboard to run it at lower temps without short-cycling, and which reduces heat loss from heating distribution plumbing, and further,  sets up the boiler run the fewest burn cycles possible, since it has only ONE zone to serve (the reverse-indirect), and isn't successively called by different zones or hot-water calls.  The burner only kicks on when the tank temp drops (either from the zones drawing water, or DHW coil inside the tank pulling heat out.)    This is a bit academic, and written from a larger-facility systems point of view but the math & concepts are identical to a multi-zoned residential application- see if you can't get your head around this: 

http://harscopk.qa.jplhosting.net/u...d0ef7d.pdf

Most residential installers haven't a clue about reverse-indirect or how to properly size a buffer tank, etc (or even how to do an accurate heat-loss calculation for sizing a boiler), and have relied on the mass of the boiler to be sufficient for running low-mass baseboard without unduly increasing cycling losses, and break it up into zones with no regard to what that does to cycling losses, boiler wear, system efficiency, etc,  but given the present and anticipated cost fuel, continuing to install such low-efficiency systems is a almost a CRIME.

Your boiler was probably sized to be able to run some overestimate of heat load AND a 5gallon per minute tub fill simultaneously.  Going with a standard indirect would be more beneficial if the boiler's output was too small to serve the hot-water draws with a continuous burn, and was at most 1.5x oversized for the peak space heating load.  But with the 113K output of this boiler you could run a standard 2.5gpm shower literally all day long without the need for a storage tank, so an indirect run as a separate zone isn't buying you too much in that regard.  (And standard controls for an indirect doesn't heat-purge the boiler into the indirect, so it would abandon heat in the boiler.) Even though it's more money and more work, re-plumbing the heating system with a reverse-indirect as the point of hydraulic separation in a primary/secondary archictecture, with the boiler-loop slaved to the aquasat on the reverse-indirect, and using a heat-purging control at the boiler buys you a LOT more in efficiency.

CT has some of the most expensive electricity rates in the lower 48.  If you can boost the summertime efficiency of the boiler to 45-50% it'll probably be cheaper to continue to run than using an electric tank (even an expensive heat-pump hybrid type) or on-demand tankless, and the capital cost for something extra just for that 3-4 months/year of savings would be somewhat wasted even if it did end up with a somewhat lower operating cost for that period.

I think I understand the distinction with a reverse indirect. Mainly that all three heating zones and DHW are pooled from the separate water tank instead of the limited amount of hot water in my boiler. The heat capacity of the water in the tank is a better buffer against temperature fluctuations from water use and/or zone heating than the small amount of 140-180 degree water in my current boiler. In a standard indirect water heating system, the tank is simply another zone in addition to the three I already have. The first contractor I spoke with about reverse-indirect pretty much dismissed it, it's certainly an interesting concept. I've got two quotes lined up, but it looks like I'm going to need to do a lot more blind calling to find someone who knows about indirect and reverse indirect and is willing to offer quotes on both. I've learned more in the past week about this stuff than I've learned in the three years I've owned the home!

How much retooling of the heating zone and DHW plumbing are we talking about with a reverse-indirect system? Shouldn't any changes that need to be made happen only at the piping around the boiler?

[edit]Well I just received my first tentative quote. He gave me a rough estimate of around $10k for a new boiler and indirect tank. I didn't mention how much I budgeted for this. He uses Buderus brand boilers and tanks. Specifically, he mentioned this line: http://www.buderus.us/products/oilheating/oilconventional/logano-g125be.html

He said he would quote the 96k BTU model, but I thought I might be able to get by on the 72K BTU version. I'm impressed by this brand's efficiency ratings and the fact that it has the outdoor temperature modulator built-in. Anyone have thoughts on this? I'll post back when I get final numbers on the quote.

It reads like you've grasped the difference between indirects and reverse-indirects, and why one might be preferable over the other based on the boiler size relative to the space-heating requirements.

Installing a reverse-indirect & heat purge controls should be relatively straightforward if you have enough room next to the existing boiler,  since your hot water and heating zone plumbing is already concentrated there.  Depending on how the existing system is pumped you may have to buy a another pump for the boiler-loop, but except for cutting in to the burner controls, the same zone controllers and pumps could probably stay.

$10K is the right order of magnitude if you're going with an all-new high-end boiler like a Buderus G125 + indirect, (a bit on the high side for a smallest-in-the-line boiler though, which is what you should be looking at- I have NO doubt that your design heat load is well under the 73KBTU/hr output of the smallest G125)  but unless your existing boiler is ready to die, re-commissioning it with a buffering indirect would be half the money, and would deliver much better efficiency than you've been running.  The smallest Buderus 125 is still more than 2x oversized for the load, and no matter what it has for an efficiency rating, as-operated in your house with your low space-heating loads it won't hit very close to those numbers without buffering. The smallest Buderous G125 series will perform similar to system # 5 in that Brookhaven Nat'l Lab study, whereas your existing boiler set up for cold start +  Intellicon/Beckett purge control + reverse-indirect would run about 6% lower efficiency than system #3 (due to its  lower steady-state efficiency than system #3). 

Look at Table 3, and consider the annual efficiency for system #5 at the 2x oversizing numbers vs. #3 (less 6%) at the 3x oversizing  for the best rough-comparison. You'll find that while #5 is  better, it's only ~4% better.  Your as-used efficency on the existing boiler as currently operated is probably similar to system #2 with 3x oversizing, or best-case, 3% less than system #1's  3x oversizing numbers.

Best bang-for buck, you're likely to be better off spending 3-5 grand on tightening up the place and adding spot-insulation where appropriate/easy, then recommissioning the existing boiler with a buffering reverse indirect & heat-purging controls.  In 10-20 years when the boiler has really had-it, a reverse-indirect should still have decades of life left in it and about any boiler could be swapped into the boiler loop with minor changes.  The costs of weatherizing an air leaky house are modest (and often subsidized by both state & federal governments).   It's pretty common to see 15-20% reductions in heating fuel use just with a solid round of air-sealing (more, for really old places with leaky double-hung windows and sagging wall-cavity insulation.)  Report back what the air-leakage numbers are from the blower-door test.

Thanks for the Brookhaven link Dana, made for an interesting read!

John

Well I just had the energy audit done. The one guy said I had the lowest leakage rate of any house he's ever done. The first blower reading was 1525cfm. The second blower door test was 1410cfm after they resealed the opening to my crawlspace. The second guy was pretty surprised as well and said there isn't much I could do unless I wanted to start dipping below standard air leakage levels and use modulated fans to pull in outside air to get the levels back to standard for mold prevention purposes. The insulation in my house was "tops" he said.

He said my boiler was only operating at about 74% efficiency due to high oxygen levels and mentioned a device that could be installed called a Heat Manager, made by Beckett. It guarantees a 10-20% oil consumption savings annually and only costs about $400 which includes installation costs. At this point, I'm looking to get the Heat Manager and the indirect tank and leave my existing boiler in place. Judging from the other quotes I've gotten, this seems like it would cost about $2200-$3000 which isn't worth applying for financing over and there might be some rebates I could apply for just for doing this.

OK we can refine things a bit. 1680 ft^2 conditioned space. Assume 8 ft ceilings = 13,440 cubic ft of air in the house. Blower door test = 1410 cfm at (I am assuming at 50 pa preasure). Multiply this by 60 (min to hours) = 84,600 cfh Divide this by the volume of the house = 6.3 ach50. Devide this by about 15 for a 3 story house and you get around 0.4 natural air changes. Generally speaking 0.35 air changes per hour is what is recommended for residential without having to use fan powered air exchange. Sonow you know air leakage is not a major problem for you.
What was the level of insulation in the attic?
It sounds like you can spend your money on heating plant upgrades. I would follow the recommendation from Dana on this.
After that, there are a couple of other possibilities to consider. The first is a solar Hot water heater for the domestic hot water, the second is a solar air heater. Both of these require access to the sun, either a wall or roof that is pointed ~ 190 deg magnetic, plus or minus about 25 degrees, that is not obstructed by trees, buildings, etc. Both of these probably have longer paybacks. IF you were doing solar hot water, you could use a single indirect storage tank that had 2 heating coils in it, one would be from the solar panel, the second would come from the boiler. This system would have to be professionally installed to work well with a reverse indirect system. While I DIYed my solar DHW system, I wouldn’t recommend it to the casual homeowner
The second option, the solar air heater, is a much easier install because the fluid it uses is air not water. These are fairly easy to install diy. I worked out the math for CT, a 2 panel solar air heater tilted vertical (wall mount) will gain about 8 million BTU’s per winter. If you do the math at the efficiency of your oil boiler that gets you to around 90 gallons of oil saved per year. If you do the install yourself, you can do it for ~ 3200$. If you assume oil will stay around 3.50$ per gallon, the simple payoff is around 10 years. It took me about 6 hours with a friend to install a 2 panel system with PV powered fan
http://www.yoursolarhome.com/solarsheat.com/solarsheat/2pak.html

Cheers,
Eric

isn't much I could do unless I wanted to start dipping below standard air leakage levels and use modulated fans to pull in outside air to get the levels back

Yes, this is what you want to do. Such a system recovers the heat in the air (which is not done when it just flows through the walls).

Posted By whatAreMyOptions on 11 Apr 2011 02:25 PM
Well I just had the energy audit done. The one guy said I had the lowest leakage rate of any house he's ever done. The first blower reading was 1525cfm. The second blower door test was 1410cfm after they resealed the opening to my crawlspace. The second guy was pretty surprised as well and said there isn't much I could do unless I wanted to start dipping below standard air leakage levels and use modulated fans to pull in outside air to get the levels back to standard for mold prevention purposes. The insulation in my house was "tops" he said.

He said my boiler was only operating at about 74% efficiency due to high oxygen levels and mentioned a device that could be installed called a Heat Manager, made by Beckett. It guarantees a 10-20% oil consumption savings annually and only costs about $400 which includes installation costs. At this point, I'm looking to get the Heat Manager and the indirect tank and leave my existing boiler in place. Judging from the other quotes I've gotten, this seems like it would cost about $2200-$3000 which isn't worth applying for financing over and there might be some rebates I could apply for just for doing this.

I'm assuming he actually meant/said "high combustion air level"  (not oxygen level) or that and that 74% was the raw combustion efficiency number quoted, not the AFUE due to oversizing.  (Alternatively he might have said something about the high oxygen levels in the exhaust gas stream, the measurement of which is part of the combustion-efficiency analysis.) Hopefully they either re-tuned  air intake the burner to get it back up to 80%+, or recommended getting a burner tech to tune it up?  But raw combustion efficiency is the upper-bound of how well it would work if burning 100% of the time, and doesn't include the standby & cycling losses I've been discussing.  You're probably looking at ~60% AFUE, as-operated due to the 74% combustion efficiency and 4-5X oversizing.

The Beckett Heat Manager is the somewhat dumber cousin of the Intellicon 3250 HW+, but either would do.  (IIRC it was Intellidyne that developed the Heat Manager design for Beckett, but continue to develop & sell the Intellicon line. I'm sure I mentioned the Beckett Heat Manager earlier in this thread.)  The HW+ does a better job of differentiating between zone calls and hot-water calls when the indirect is set up as a separate zone (as opposed to the buffer-centric "reverse indirect" system)  using a slightly different algorithm to handle the HW call.  Either device should be under $500, installed. They both work the same way using similar algorithms, but if you're not doing a reverse-indirect, the Intellicon is probably going to give you a slight performance edge over the Heat Manager on the calls from the indirect, and IIRC it works better on cold-starting systems better than the Heat Manager (which could be huge performance advantage in summer.)  This system SCREAMS for a heat-purging boiler control (any is better than none), and it would likely pay for itself in one heating season.  But for even-money (or even $100 more) the Intellicon HW+ would be a better bet.  Street price on them is under $200, often under $150, and the installation time is identical to the HM.

As separate zones it will still have at least 2-3x the number of burner cycles than it would with the reverse-indirect as buffer approach though.  You'll still see a double-digit reduction in fuel use with a heat-purging control even without buffering, but with a buffering reverse indirect the system can be tweaked for even more, by being able to lower the average temp of the heating system water. (It'll be ~2-3% for every 10F you can drop it.)  Given your fuel use and house-tightness you can probably still stay warm running with 140F water in the baseboards, but without the buffer running it that cool would destroy the boiler. (The explanation for this may be a bit much for those with no interest in becoming Jr Hydronic Heating designers though.)

Congratualions on your relatively low air leakage (it's not super tight, but tighter than most).  Going even tighter and buying a heat-recovery ventilation system is still the right thing to do long term though- your indoor air will be healthier, and fuel use lower.  Your relative tightness and high-score on the insulation inspection probably explains why your fuel use is as low as it is, even with a detuned 5x oversized boiler.

Posted By jonr on 11 Apr 2011 04:36 PM
Yes, this is what you want to do. Such a system recovers the heat in the air (which is not done when it just flows through the walls).

I'm not sure the cost to implement this system would be worth any savings I would receive. I only plan to be in this house another ten years.

Posted By Dana1
I'm assuming he actually meant/said "high combustion air level" (not oxygen level) or that and that 74% was the raw combustion efficiency number quoted, not the AFUE due to oversizing. (Alternatively he might have said something about the high oxygen levels in the exhaust gas stream, the measurement of which is part of the combustion-efficiency analysis.) Hopefully they either re-tuned air intake the burner to get it back up to 80%+, or recommended getting a burner tech to tune it up?

No they didn't tune it up, but I will be scheduling my spring boiler cleaning and will mention it to the technician when he comes.

Posted By Dana1
As separate zones it will still have at least 2-3x the number of burner cycles than it would with the reverse-indirect as buffer approach though. You'll still see a double-digit reduction in fuel use with a heat-purging control even without buffering, but with a buffering reverse indirect the system can be tweaked for even more, by being able to lower the average temp of the heating system water. (It'll be ~2-3% for every 10F you can drop it.) Given your fuel use and house-tightness you can probably still stay warm running with 140F water in the baseboards, but without the buffer running it that cool would destroy the boiler. (The explanation for this may be a bit much for those with no interest in becoming Jr Hydronic Heating designers though.)

I will ask about installation of the Intellicon device when I choose a contractor. If I want to apply for a CT Energy loan through AFC and get the low financing, I have to use an approved contractor/company. The problem I'm having is finding anyone who knows what a reverse indirect system is.
I did get another quote later in the day from the same people who performed the audit. Their rep had a solution that I hadn't considered- splitting off the DHW into an on-demand propane fired water heater. He gave me a rough estimate of $3300 for installation and annual rental fees for the propane tank would be $100. He mentioned that my steel oil boiler should be kept running during the summer at a minimal temperature such as 65F. If I drain the water from the boiler, could I then completely shut it off during the summer and thus keep my oil tank full until I needed it in the fall?

will ask about installation of the Intellicon device when I choose a contractor. If I want to apply for a CT Energy loan through AFC and get the low financing, I have to use an approved contractor/company. The problem I'm having is finding anyone who knows what a reverse indirect system is.
I did get another quote later in the day from the same people who performed the audit. Their rep had a solution that I hadn't considered- splitting off the DHW into an on-demand propane fired water heater. He gave me a rough estimate of $3300 for installation and annual rental fees for the propane tank would be $100. He mentioned that my steel oil boiler should be kept running during the summer at a minimal temperature such as 65F. If I drain the water from the boiler, could I then completely shut it off during the summer and thus keep my oil tank full until I needed it in the fall?

OK here is my take on propane.
Advantages: generally higher efficiency, quiet, no oil smell works great for low heat loads. You can also use a propane dryer and range.
Disadvantage: often expensive fuel, tank rental fees, locked into one supplier for propane unless you own the tank. Small tank ~50-100 gallons they will charge a premium to fill it. In ct only the company that owns the tank can fill it so they have you by the short hairs.
I think it is only worth it to go to propane if you are going to do a complete conversion, and you are going to own the, large tank, preferably inground. This allows you to shop for propane. IF you do this, it can be a great way to go.
I would then spec a Mod con Propane boiler with heat purging and outdoor reset correctly sized via Manual J with actual infiltration numbers) with a well insulated indirect tank for DHW. At the same time this allows you to run much lower temp water through the baseboard during the shoulder seasons.
In your case with an oil bill of 580 gallons per year, but low efficiency(~60%), you are looking at about the same in gallons of propane per year. 45% Less heat content per gallon, but much higher efficiency. I would use a 1000 gallon buried tank. This gets you down to one fill up per year and also allows buying it during the summer when prices are traditionally lower.
One other advantage is if they ever put in the piping for natural gas, you can convert with minimal expense.
The price of propane has historically been higher per BTU in Connecticut. The price of Propane is tied to an extent to the cost of oil.
http://www.eia.doe.gov/dnav/pet/PET_PRI_WFR_DCUS_SCT_W.htm
Currently fuel oil =3.98$/ gal average *139000 btu/gal = 35,000 btu/ per dollar retail delivered
Currently propane =3.21$, gal average *93000 btu/gal = 29,000 btu/ per dollar average retail delivered. you can do quite a bit better than this if you own your own tank and price shop. I am burning 1.81$ propane at the moment. My father, who rents a 50 gal tank is paying about 4.10$ per gallon (different company). Now if you take into account the fact that the efficiency of a propane system is much higher, it is a good deal, if you were getting a new furnace anyway.
The good part from a supply and demand perspective is propane comes from crude oil(50% of the US market) AND as a byproduct of Natural gas production (50% of the us market). Since the newly found reserves of Nat gas are huge, propane should be more price stable than oil going forward.

Confused yet?
Cheers,
Eric

Posted By whatAreMyOptions on 12 Apr 2011 10:03 AM

Posted By jonr on 11 Apr 2011 04:36 PM
Yes, this is what you want to do. Such a system recovers the heat in the air (which is not done when it just flows through the walls).

I'm not sure the cost to implement this system would be worth any savings I would receive. I only plan to be in this house another ten years.

Posted By Dana1
I'm assuming he actually meant/said "high combustion air level" (not oxygen level) or that and that 74% was the raw combustion efficiency number quoted, not the AFUE due to oversizing. (Alternatively he might have said something about the high oxygen levels in the exhaust gas stream, the measurement of which is part of the combustion-efficiency analysis.) Hopefully they either re-tuned air intake the burner to get it back up to 80%+, or recommended getting a burner tech to tune it up?

No they didn't tune it up, but I will be scheduling my spring boiler cleaning and will mention it to the technician when he comes.

Posted By Dana1
As separate zones it will still have at least 2-3x the number of burner cycles than it would with the reverse-indirect as buffer approach though. You'll still see a double-digit reduction in fuel use with a heat-purging control even without buffering, but with a buffering reverse indirect the system can be tweaked for even more, by being able to lower the average temp of the heating system water. (It'll be ~2-3% for every 10F you can drop it.) Given your fuel use and house-tightness you can probably still stay warm running with 140F water in the baseboards, but without the buffer running it that cool would destroy the boiler. (The explanation for this may be a bit much for those with no interest in becoming Jr Hydronic Heating designers though.)

I will ask about installation of the Intellicon device when I choose a contractor. If I want to apply for a CT Energy loan through AFC and get the low financing, I have to use an approved contractor/company. The problem I'm having is finding anyone who knows what a reverse indirect system is.
I did get another quote later in the day from the same people who performed the audit. Their rep had a solution that I hadn't considered- splitting off the DHW into an on-demand propane fired water heater. He gave me a rough estimate of $3300 for installation and annual rental fees for the propane tank would be $100. He mentioned that my steel oil boiler should be kept running during the summer at a minimal temperature such as 65F. If I drain the water from the boiler, could I then completely shut it off during the summer and thus keep my oil tank full until I needed it in the fall?

If you're looking at a 10 year payback on any energy improvements, skip the on-demand propane water heater.  DO install a heat-purging controller and set up the boiler for cold starting.  But then look at the installed price difference between a buffering reverse-indirect vs. a standard indirect.  You'll get higher water heating performance and lower fuel use out of a buffering reverse indirect, but if it's $2500 more money (not likely) it may not pay back within your time frame. 

With 113KBTU of burner behind it you'll get as much "first-hour" hot water out of an Ergomax E23 or TurboMax 23 reverse-indirect as you would the propane tankless, and the cost per delivered BTU might be slightly higher with the lower-efficiency boiler than with a condensing propane tankless the difference in installed price would take decades to pay off.  (You'll get a LOT more hot water performance out of any indirect than with your embedded coil.)

You might call the manufacturers of buffering indirects to see if they have a distributor/installer working in your area. 

http://www.ergomax.com/

http://www.thermo2000.com/content/en-US/s6_contact/coord.aspx

If you run the shower (not the tub) more than 30 minutes/day for all showers, a drainwater heat exchanger as pre-heat to the hot water would pay off in that time frame.  The cut the energy used in a shower by about half, but not batch draws like tub baths or clothes washers, etc.

Posted By Dana1 on 12 Apr 2011 01:39 PM
You might call the manufacturers of buffering indirects to see if they have a distributor/installer working in your area.

http://www.ergomax.com/

http://www.thermo2000.com/content/en-US/s6_contact/coord.aspx

If you run the shower (not the tub) more than 30 minutes/day for all showers, a drainwater heat exchanger as pre-heat to the hot water would pay off in that time frame.  The cut the energy used in a shower by about half, but not batch draws like tub baths or clothes washers, etc.

Showers are 20 minutes tops total during a single day.
I did look into those websites. There is only dealer listed in CT for Thermo2000 and I couldn't get ahold of anyone at Ergomax, but I will try tomorrow.

Posted By eric anderson on 12 Apr 2011 11:32 AM
OK here is my take on propane.
Advantages: generally higher efficiency, quiet, no oil smell works great for low heat loads. You can also use a propane dryer and range.
Disadvantage: often expensive fuel, tank rental fees, locked into one supplier for propane unless you own the tank. Small tank ~50-100 gallons they will charge a premium to fill it. In ct only the company that owns the tank can fill it so they have you by the short hairs.
I think it is only worth it to go to propane if you are going to do a complete conversion, and you are going to own the, large tank, preferably inground. This allows you to shop for propane. IF you do this, it can be a great way to go.
I would then spec a Mod con Propane boiler with heat purging and outdoor reset correctly sized via Manual J with actual infiltration numbers) with a well insulated indirect tank for DHW. At the same time this allows you to run much lower temp water through the baseboard during the shoulder seasons.
In your case with an oil bill of 580 gallons per year, but low efficiency(~60%), you are looking at about the same in gallons of propane per year. 45% Less heat content per gallon, but much higher efficiency. I would use a 1000 gallon buried tank. This gets you down to one fill up per year and also allows buying it during the summer when prices are traditionally lower.
One other advantage is if they ever put in the piping for natural gas, you can convert with minimal expense.
The price of propane has historically been higher per BTU in Connecticut. The price of Propane is tied to an extent to the cost of oil.
http://www.eia.doe.gov/dnav/pet/PET_PRI_WFR_DCUS_SCT_W.htm
Currently fuel oil =3.98$/ gal average *139000 btu/gal = 35,000 btu/ per dollar retail delivered
Currently propane =3.21$, gal average *93000 btu/gal = 29,000 btu/ per dollar average retail delivered. you can do quite a bit better than this if you own your own tank and price shop. I am burning 1.81$ propane at the moment. My father, who rents a 50 gal tank is paying about 4.10$ per gallon (different company). Now if you take into account the fact that the efficiency of a propane system is much higher, it is a good deal, if you were getting a new furnace anyway.
The good part from a supply and demand perspective is propane comes from crude oil(50% of the US market) AND as a byproduct of Natural gas production (50% of the us market). Since the newly found reserves of Nat gas are huge, propane should be more price stable than oil going forward.

Confused yet?
Cheers,
Eric

Good to know. I will probably avoid a hybrid propane/oil system in that case as the cost for digging and buying the tank outright outweigh any benefits to be had in only a 10 year period.

One of the guys that came to my house for a quote mentioned that my boiler was not a good candidate for cold start and that I would have to leave it running at 60-65F even during the summer if I were to split off the DHW into some other direct heated system. Is this BS? Also, is it safe for me to completely turn off my boiler during the summer until it is needed in the fall, assuming my DHW is no longer part of it?

I you can informally find out from the dealer who is buying the Thermo 2000s or ErgoMax in any quantity you'd likely find somebody who knows what they're about. A third alternative is the Everhot EA reverse-indirects:

http://www.tfi-everhot.com/pdfs/TFI_EAseries.pdf

http://www.tfi-everhot.com/contact.html

You'd want something at least 25 gallons- the 30-gallon EA 8-50 is probably the right one for your application (3 gallons more than the smallest Thermomax or Ergomax.)

With either the Everhot EA or ThermoMax to be plumbed as the hydralic seperator some connections have to be built-up externally. The ErgoMax is a more straightforward install, since it has both boiler out/return and heating out/return connections built into the tank, whereas with the others you'd need to Tee-in the boiler/heating loop seperation at the tank's boiler out/return connections. (Not a big deal, but requires more smarts from the installer/designer.)

Key to getting the efficiency out of it is to COLD START the boiler, and let the aquastat on the tank control the boiler loop pump. That way the mass of the tank protects boilers not designed for cold starting by rapid ramp up to near the tank's temp (which should be set no lower than 140F for an oil boiler.)

Well I bought the Intellicon HW+ 3250 from a reputable seller for about $170. At that price I couldn't really pass it up. I'll look into installing it myself. I'll know right away if the installation is something I can handle.

If I didn't have nat gas and geo didn't pay back quick enough, then I'd use an air source heat pump whenever outside temperatures allowed it. Plus insulation and sealing and an efficient fossil fuel furnace for the colder weather.

At this point I'm pretty sure I'm going to just put in a 40 gallon GE electric water heater from Home Depot or a similar model from Bradford White. WIth the specific GE model I was looking, I'd be looking at a monthly operating cost of about $36 at my current KWH rates. To top it off, I'm guessing even with the added cost of an electrician running conduit from my breaker box to the outside of my house along the side and back into the boiler area and the installation costs of the water heater itself, it's only going to be around $1500. This will let me turn off my boiler during the warm months and my electric bill will see a 30% increase on its average of $120.

Posted By whatAreMyOptions on 15 Apr 2011 03:51 PM
Well I bought the Intellicon HW+ 3250 from a reputable seller for about $170. At that price I couldn't really pass it up. I'll look into installing it myself. I'll know right away if the installation is something I can handle.

Ease of installation will vary a bit from boiler to boiler, depending on which aquastat(s) are used and how it's configured. Hopefully you can get decent documentation for the 1990s version of the boiler (which may not be very different from the current version . See p.12 & 13 for the simplified schematic.) Different aquastat controls have likely been used in different models/years, so you may have to look up the aquastat manufacturer's documentation to figure it out completely.

You may find it useful to look at the installation schematics for particular aquastat model numbers in the Beckett Heat Manager installation instructions, and compare notes with the manual for the Intellicon-branded version.

Since you're not going to have an external buffer you probably shouldn't set it up for cold-starting with the circulator on, since you can't use the thermal mass of the buffer to pre-warm the boiler on a startup, and repeated cold starting may damage a boiler not designed for that use.  You can set it up to idle as low as 140F without much risk of damage, which cuts your idle losses roughly in half from what it is when running  the 180F HI/160F LO recommendation for running it with the tankless coil.