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.