Posted By geome on 10 May 2010 03:41 PM

Posted By eric anderson on 10 May 2010 02:44 PM

 I would always  want to lower the amount of BTU's I need before I tried to get the BTU's cheaper. 

It's the word "always" that I don't necessarily agree with.  If a homeowner's current HVAC system is on the way out (this is not the case with the OP), choosing geothermal may be a good first choice if funds are not available for both a new system and new/upgraded insulation, windows and doors.  Of course, gaping holes are a different matter.  In a perfect world, I would agree with your reasoning.

Agreed.
If the current HVAC is toast, the cost to go geothermal is  the differential cost vs a new oil or gas system.  That may make it alot more cost effective.  If I could get way cheaper energy, it would make sense.  However with electicity being expensive in the north east, geothermal is not so attractive right now.  With insulation, there is always a point of diminishing return, but if you are using 1500 gallons of oil per year, you have alot of room to improve.  An energy audit would be a great place to start.

Eric

Ultimately, the decade-average price of oil is determined by the growth rate & energy policies of China & India, not speculators (although speculators will affect the annual averages significantly.) Going forward, my crystal ball sez there's not an intermediate or long term future in oil as a heating fuel- demands from the transportation sector worldwide for diesel & jet fuel are in direct competition for that same fraction of an oil barrel. I'm betting a farmer in India is willing to pay more for a gallon of diesel (subsidised or not) in 2020 than would be reasonable to spend on heating a non-superinsulated house in New England.

The same crystal ball sez that intermediate-term for natural gas in New England & mid-Atlantic states looks favorable, as the only recently tapped Allegheny shale reserves get developed. If you're on the gas grid, a condensing gas furnace retrofit would be cheaper (& more comfortable) than tepid-air geo.

If your air-conditioning load isn't much (usually isn't, in NH), a seaonal-average COP of 3.0 might be difficult to achieve, since you're only drawing heat out, rarely/never injecting heat in, with a relatively long heating season. Subsoil temps in NH are in the 40s Fahrenheit, but by the middle of the heating season you may see ground loop temps under 30F (yup- FROZEN!) and relatively dismal COPs. This can be mitigated by more heat exchanger/deeper wells, etc, but only at some expense, further diminishing returns on cash invested. I'm sure somebody's system in NH has hit 3.0 for a seasonal average, but I'd be surprised if that were typical real-world verified performance. In RI/CT where the subsoil temps are warmer, heating season shorter, and heat loads lower an average of 3 might be realistic (but not 4.)

If you're on a gas-grid and can get reasonable net-metering terms with the electric utility, a cogenerator/condensing furnace/hot water combi like the Freewatt (google it) will be considerably cheaper up front than geo , and will have an overall lower net operating cost (and lower carbon footprint) than a geothermal system. (A guy in my office was an early adopter of the hydronic version, and by the end of it's 3rd year of operation had paid for itself in fuel & electricity savings over the high-mass boiler that it replaced.)

Wood boilers/pellet boilers can be a reasonable approach in some parts of New England, not so much in others. Installing the boiler & buffer tanks outdoors and using a hydro-air system hooked up to the original ducts can work.

Condensing oil heating appliance aren't ready for prime time in the US market (the boilers might be, but the available fuel isn't). The condensate has significant sulfuric acid, and is a disposal problem. But as the developing world imparts higher demand on oil as transportation fuel, any savings you might reap this year in higher-efficiency will likely evaporate in higher fuel costs down the road. (cood be rong offen am)

According to NH Climate Audit (see http://nhclimateaudit.org/calculators.php) the average geo system in NH runs a seasonal COP of 2.75, and at ~15cents/kwh is ever so slightly cheaper to run than $1.32 natural gas in a 78% AFUE furnace, both of which are MUCH cheaper to run than a 78% oil burner. (86% is about as good as oil-burners come without going super-high-tech- you won't improve on that much.) Electricity isn't likely to get cheaper going forward, but natural gas is. A 90% gas fired furnace even at 2010 rates would be cheaper than running geo,( but still way more than a condensing gas cogenerator system like the Freewatt after electricity credits.) Cord wood burned in a 60% wood stove is the only thing else in that range fuel-cost wise. (70% wood boilers & stoves are available too.)

Whatever heating system replacement you opt for, be sure to get a room-by-room & whole house heat load analysis from either the system designer or the contractor, and DO NOT OVERSIZE BY MORE THAN 15%. Oversized heating/cooling equipment ends up being significantly less efficient & higher maintenance due to excessive cycling under part-load conditions. Using your historical fuel use against annual heating-degree-day data and the DOE efficiency ratings on your oil burner it's pretty easy to put a fairly accurate stake in the ground for design-day heat loss. If experience is any guide, a heating contractor that won't/can't do the math will end up oversizing by ~2x, but often as much a 4-5x. Every decent heating/cool system begins with an accurate heat-loss analysis, but it's a step usually skipped, with the tendency to going larger rather than smaller so as to preclude any chance of 5AM call from a cold & irate customer. Rare is the customer who calls up screaming that they're only pulling a COP of 2.0, or that their 85% AFUE furnace is only averaging 73%, but that's what's actually happening in the real world. Right-sizing the equipment is step-1 on avoiding that pitfall.

Well, I need to correct the 1500 gallons. Here are the details:

 

House is 3200 sq feet but with 700 sq feet to 16 feet high ceiling (yea I know this was a mistake). Windows are not small either.

 

We currently use about 1000 gallons of oil plus we have a high efficiency fireplace insert and we use about 2 cords of wood in our big family room with 16 feet ceilings. Kids play in this room so we keep the temp at between 72-74 deg. Wood is great for that localized heating. The rest of downstairs and upstairs stays at 70. I guess I made an error about BTU of wood and I forgot about efficiency of the wood appliance. The insert is 65% efficient so I think adding the wood we probably use 1200 gallons, but if we kept the temp at 70 we would probably be at 1000 gallons. I consider the house to be well insulated considering we have about 4000 sq feet of 8.5 feet ceiling and big windows.

 

You are right my builder put a huge 140,000 BTU furnace. I since downsized it to about 100,000 BTU (by replacing the nozzle for smaller as manufacturer specified) but it is still too big. Even at -20 deg F and strong wind the furnace never worked all the time. I think I need more like 50,000 BTU, but heat loss needs to be calculated by a professional.

I am learning so much in here...

Can't argue with much of Dana's well-written post.

I agree that recent trends indicate cheaper NG for awhile to come, but just as Indian farmers are competing for Diesel fuel, so too are new electric power plants competing for NG. It is by far and away the easiest fuel for new power plants since coal is unpopular and wind / solar will comprise a tiny fraction of grid power for at least a decade.

We've seen NG price and availability gyrate wildly, just as with oil.

Too bad I don't have NG. I used to heat with NG in Canada (Winnipeg, one of the coldest city in North America). I never noticed heating bill it was so small.

Question:
If I spend capital to reduce a perpetually recurring expenditure, (i.e., heat),
do I count that as a "return on investment," or just a "smaller expense?"

Answer:
WHO CARES!!!

I care, Looby, because return on investment is too simplistic to evaluate capital expenditures. As I wrote before, a life cycle cost analysis looks at all the factors, including expected lifespan and upkeep. If I traded my Isuzu for a Prius, would I allow the sales person to describe my decision as an investment based on projected gasoline savings? Absolutely not, because cars and heat pumps get used up.
Seriously, you need to drop the S&P 500 while you look merely ridiculous. The 500 stocks represent about 70 percent of the stock market's value, so any talk of the index systematically outperforming the market is jabberwocky. Kind of hard to make the dog to wag the dog.
Applying survivorship bias to the 500 is also BS. Enron stock fetched $1 on 12-11-2001 when it was booted from the 500 index (because it filed for bankruptcy on 12-4.) Investors in the many mutual funds that passively track the 500 lost real money on Enron. But the Vanguard 500 Index, to name one, has returned 10.46 percent a year since its inception in 1976. If VFINX is an example of burying mistakes, as you say, maybe we should look for money managers holding shovels.

Posted By toddm on 10 May 2010 09:32 PM
If I traded my Isuzu for a Prius, would I allow the sales person to describe
my decision as an investment based on projected gasoline savings?

You seem uncommonly concerned about how some grifter in a polyester
suit chooses to describe things. Call it whatever you like, but it's been my
experience that a dollar saved spends every bit as well as a dollar earned.

"Stand firm in your refusal to remain conscious during algebra;
in real life, I assure you, there is no such thing as algebra."
- Fran Lebowitz

Geo isn't a good fit everywhere. In my territory (mid-MI) it creates positive cash flow immediately for anyone who borrows money to install it (saves more on operating cost than the loan payment) on a 10 year note as long as I am not comparing to natural gas (and sometimes even then). Of course our electricity is as little as $.075kwh and no more than $.11. That is including one-time start-up expenses (loop fields and electric system modifications) that are not true of subsequent replacements (which are less frequent than fossil fired equipment).
I confess to confusion when no one expects any low end heating system to "pay for itself". If you have to have a heating system... wouldn't you want a high end one that "pays you back" the price difference (and more) within it's lifecycle and makes it's own payments with fuel savings, provides even and safer heat, costs little more than fossil equipment to replace (years later than their lifecycle)? It would seem to be a no brainer.
Of course some folks pay more for electricity and some are very disciplined investors who will find a higher ROI vehicle......and that is why it is not for everybody. Just don't try to suggest that anything available is a wiser investment for everybody's "heating" dollar.
Good luck,
Joe

I agree with Dana1, the future outlook for oil is bleak at best, with India and China markets getting more automobiles to the general public, the demand will continue to grow with a fixed or dwindling Supply.  Sooner or later oil price will sky rocket to unaffordable levels to some (thus reducing demand) it might be 10 years down the road, it might be 50, but it will happen sooner or later.  I'm leaning more towards sooner.  Anyway, your right, the numbers might not add up to significant saving yet for you at the current price of heating oil.  And perhaps you could wait another 5 years before making a move, but I wouldn't wait too long, when the numbers look favorable or very favorable, you might be last in long line of people waiting to get a system installed.  While the current numbers might not be ideal, I still think it's a great investment over the long haul.          
As for the stock market, it should have no bearing on your decision, you shouldn't think about how much money you could make on the stock market over time instead of investing in a geo system. The same logic could be apply to everything, I could be a millionaire now if i still lived at home, ate rice for all my meals, took the bus to work and invested every extra cent i earned in the stock market.  At some point you have to spend money on something, even if you could earn higher yields elsewhere. 

"At some point you have to spend money on something, even if you could earn higher yields elsewhere. "

"If you have to have a heating system... wouldn't you want a high end one that "pays you back" the price difference (and more) within it's lifecycle and makes it's own payments with fuel savings, provides even and safer heat, costs little more than fossil equipment to replace (years later than their lifecycle)? "

I think we're on the same page here TG.

I meant to address the "Freewatt" comments last night......Balls! If you want to talk about a really poor ROI, buy yourself one of these. No way it compares to geo. Less efficient than a dedicated gas appliance as a furnace and a poor yield generator all in one. Payback in less than 5 years would take a miracle (unless you use one of those DIY scales that neglects to mention a few expenses). Even the manufacturer (curiously ECR...they claim no affiliation with Earthlinked) suggests that it is more for green-thinkers than ROI. How about maintenance? Don't forget to change the oil on your furnace........
Not new technology or concept. "York Triathalon" ~circa 1990. Maybe the idea is going to take off in anaother decade or two.
j

Posted By engineer on 10 May 2010 08:08 PM
Can't argue with much of Dana's well-written post.

I agree that recent trends indicate cheaper NG for awhile to come, but just as Indian farmers are competing for Diesel fuel, so too are new electric power plants competing for NG. It is by far and away the easiest fuel for new power plants since coal is unpopular and wind / solar will comprise a tiny fraction of grid power for at least a decade.

We've seen NG price and availability gyrate wildly, just as with oil.

True, NG is becomeing the replacement fossil fuel of choice for fossil-power going forward in New England in anticiapation of carbon taxes making coal uneconomic.  But as NG prices rise, so will electricity prices.  Even in best-in-class combined-cycle gas plants the fuel to load efficiency isn't much better than 60%, so you're still unlikely to find geo at a COP of 2.5 to beat a 90%+ condensing gas fired heating unit in lifecycle cost.   The average fuel to load efficiency of the fossil fired grid is about half that  of a combined-cycle generator. A micro-cogenerator like the kilowatt-Honda used in the Freewatt system runs only ~20% efficiency as a generator, but better than 75% as a heater- the combined fuel efficiency is around 95%.  Net metered at New England retail-residential it would be tough to beat with standard geo.

While NG does have significant price volatility, sheer size of the Allegheny shale deposits will have a moderating effect on price averages going forward as it becomes developed. (So far we haven't even seen the frost on the tip of the iceberg from these deposits entering the gas grid.  This is a HUGE untapped resource, previously unavailable due to now-cleared technological hurdles for production.)  Regionally, wind power is going to have a tough time competing with combined-cycle NG & cogeneration, so I don't expect wind to become a major player without significant subsidy or outlandish levels of carbon taxation- the unimpeded marketplace alone won't drive the price high enough. (I heard this morning that the agreed to wholesale price of power from the Cape Wind project in MA is just north of 20cents/kwh- that's WHOLESALE!)

They do have propane versions of the Freewatt- cost-wise not the slam-dunk choice that NG is, but probably still way better than oil if the net metering is reasonable, at roughly half the capital cost of geo.  While traditionally propane has tracked the price of oil (and higher cost per delivered BTU), that is also poised to change as propane production from shale-gas fields becomes larger than propane production from oil-refining.  Fired in a Freewatt the payback on electricity if net-metered at the retail (~15cents/kwh NH average) may beat geo for operating cost, but do a serious financial analysis on it before diving in- the fuel cost numbers & fine-print on net metering matter.

If the true design-day heat load of this place is ~50KBTU or less it's impossible to "right size" it with a standard oil-burner- the fuel available in the US isn't clean enough to micro-nozzle a standard burner down below ~75K or so, but 1.5x oversizing of a low-mass heating system like hot-air isn't nearly as bad as 2-3x or greater oversizing. 

But a decent efficiency wood boiler with a well insulated buffer tank & hydronic coil in an air handler could make heating entirely with wood utilizing your existing ducts quite reasonable & cost effective.  With a well insulated buffer tank the losses from the burner being oversized drops dramatically, and wood-boiler systems are designed to be buffered in order to run flat-out for highest combustion-efficiency/lowest-emissions. (The smallest wood boilers I've seen are in the 100KBTU range, eg Buderus G201-5 )  If you're going for max-comfort max-efficiency a variable speed ECM drive air handler can run nearly continuously to match the instantaneous heat load drawing heat from the buffer.  It'll take some system design work but there may be wood-boiler folks in your area familiar with how it's done.  There are quite a few wood-boiler/radiant-floor systems out there running at similar water temps that you'd want for hydro-air, and given how oversized your initial system was it shouldn't be tough to retrofit a coil/air handler system that can deliver design-day heat with 120-140F water, with very comfortable exit-air temps at the registers.   (I have a hydro-air zone zone to several rooms in my home running with ~125F water from a buffer tank, and the exit air at the coolest register is a quite pleasant ~108F. The same air handler has an AC coil as well, not that we have to run it much in the summer.)  A geo system would likely need a new duct system to work well, and would need to deliver the heat at temps below what's comfortable blowing on human skin in order to make the COP reasonable.  Geo-radiant is a much cushier solution, but even more expensive to install as a retrofit.  If you're up for going with bulk fuels, this type of system is likely to be lower lifecycle cost than geo in the forests of NH.  Find a local wood boiler supplier/distributor, see if they have any system designers to recommend.

Doesn't PSNH also offer additional rebates or incentives for geothermal heat pumps? Check it out at www.dsireusa.org.

I've been meaning to check back in on Freewatt and similar CHP (Combined Heat and Power systems). I keep a vague eye on those but haven't updated myself recently. Cogeneration of power and heat is routine in some industries; those with heavy demands of both, such as paper mills. CHP units bring that advantage into a home.

Do net metering agreements / rules typically extend to CHP units or are they reserved for non-combustion sources of power (PV, hydro or wind)?

It is hard to get around the grid's inefficiency from coal mine to house loads.

Dana1, we have been using our high efficiency fireplace insert for a few years now. It is wonderful but adding wood is a pain in the rear end. Having a wood boiler and feed it often is not what I would like to do.

 

Could you tell me guys what the annual maintenance costs are for geo, coil flushing and so on?

 

I got much better estimate and the second estimate is coming much better as well. I need very little duck work for the geo. However from Dana 1 and from NH climate audit the data for GEO comes with COP of 2.5-2.75. Considering the COP and new estimates oil would have to be at 2.80 for the geo to pay for itself in about 10 years. We know long term oil prices are going up but near term 2-10 years is anyone’s guess, especially with the economy being what it is today.

 

I don’t need a new system since my current oil is only 5 years old (same as the house).  The reason I started looking at the geo is that I was thinking about putting a central air conditioner. In my payout calculations in this (most current post) I subtracted from the geo price cost of putting in an air conditioner.

 

I am not in a hurry at this point so doing the homework is the right thing to do. The only area I don’t know much about is geo maintenance costs.

 

Andrzej, what type of system are you considering? Loop type? I assume water/air. Closed loop may have lower maintenance costs (no coil flushing for instance) but I don't know which would work best in your situation. Make sure a Manual J heat load calculation is done as Dana1 suggested.

Not much maintenance with our closed loop system. Get a good air filter and change as recommended. We like electrostatic filters because they are re-usable, but they need to be washed periodically (get 2 or 3 if you go this route so you don't have to clean them in the middle of the winter.) Periodic maintenance should include an operation test, electrical readings, cleaning of coil and blower if needed, checking loop pressure with a closed loop system, periodic flushing of the coil with an open loop system (frequency depends on water conditions), heat of extraction/rejection calculation. Others here can give you more specific info. Some of these things can be done by a competent homeowner. Your installer may have annual service agreements that may include these things.

I would look for a 10 year warranty for everything. This is what we have. It cost a little more, but the piece of mind is wonderful.

I second the motion for lowering the Btu count... to passive house numbers first, last and always.

I think the idea should be to stop using fossil fueled electricity period.
aj

Posted By adkjacUpstateNY on 12 May 2010 01:57 PM
  first, last and always.

As I said, while reducing load is good, I live in the real world where this is not always possible from a cost standpoint.

Posted By engineer on 11 May 2010 08:51 PM
I've been meaning to check back in on Freewatt and similar CHP (Combined Heat and Power systems). I keep a vague eye on those but haven't updated myself recently. Cogeneration of power and heat is routine in some industries; those with heavy demands of both, such as paper mills. CHP units bring that advantage into a home.

Do net metering agreements / rules typically extend to CHP units or are they reserved for non-combustion sources of power (PV, hydro or wind)?

It is hard to get around the grid's inefficiency from coal mine to house loads.

Most states/utilities with net-metering rules do not have different rules for micro-cogens (I don't know of any that do.)  Check with your local utility- they are the arbiters of how and what gets hooked up with the grid- they'll know. (Or email the Freewatt folks, they'll usually respond within a business day.)

IIRC Marathon has oil-fired micro-cogens, but they're probably all too big for this app: power output higher than most residential net-metering agreements allow, and thermal outputs far bigger than his average heat load- it would need a HUGE buffer to be reasonable.

Posted By Andrzej on 11 May 2010 10:19 PM

Dana1, we have been using our high efficiency fireplace insert for a few years now. It is wonderful but adding wood is a pain in the rear end. Having a wood boiler and feed it often is not what I would like to do.

Wood boilers aren't nearly the pain that wood stoves & fireplaces are. They're far more than ust a glorified wood-stove, but they're clearly not for everyone. The better systems are fairly automated and with a reasonable buffer tank you can typically get away with stoking it once, or at most twice/day during colder weather and less often at lower average heat loads.  Pellet boilers are even more automated, with large hoppers and automated auger feeds, etc.  A friend of mine in a typical 1990s vintage 5 bedroom house in a suburban development heats his place with a pellet boiler and LOVES it- especially when the oil truck is filling up his neighbor's tank. :-)  He was very self-congratulatory about it during the oil price spike.  Another family I know has a mid-sized wood boiler heating a large antique house with retrofit radiant floors. IIRC he said it can handle 3' logs, and they have never filled it more than once/day. (I don't have the specs on his buffer tank relative to the BTU output of it the beast.)

Don't rule it out based on your fireplace-insert experience- there are a wide variety of designs out there with varying degrees of automation.  With the kind of heat loads you seem to be talking your fuel handling labor isn't likely to be much. Pellet boilers with large hoppers aren't much more work than ordering another pellet delivery as the supply runs down (not much different than getting your oil tank filled), but wood boilers will require a modest amount of manual labor.

OTOH one of my employees heats her place with a pellet stove that IS little more than a glorified wood stove and actively hates it (primarily 'cuz she buys the fuel in bags rather than bulk, doesn't have a large hopper, and at 5'0' she isn't strong or tall enough to easily heft the bags up to the top of the hopper.)

A neighbor has an automated pellet boiler for heat and hot water. I believe he puts pellets into the automatic feeder once per week in the winter (VA winter.) He told me that his pellet prices have increased 2-2.5 times since he installed it about 4 years ago and that he has changed his pellet supplier several times due to price and supply issues. Overall, he likes the system. If you decide to go with something like this, verify your supply ahead of time and I would ask for pricing history to check for price stability.

This system doesn't help with air conditioning costs though. He is looking into getting a wind turbine. We decided to go geothermal instead. :-)