I'm in the midst of my second ICF build.  The first was in the upper midwest, this is in the south.  2600sqft, full ICF (foxblocks), full basement.  I can't decide if the upcharge for GEO is worth the payback even with the 30% uncle sam giveback.  Looking at costs, I hae been quoted $39K for GEO (3 ton waterfurnace) 25K for conventional.  Systems include trane electronic air cleaners, renewaire air to air exchange, renewaire ultra quiet bathroom fans.

Does anyone think these prices are out of line?  Please express your opinions on the subject as I am closing in on teh first pour and need to get the penetrations sleeved before proceeding.

Does that include the basement? You might want to post this on the geo thread.

Assuming you have sufficient taxable income to get the entire 30% credit, your cost is 25K conventional and 27.3K for the Geo after uncle's help. Depending on your local utilities, there may be additional help from them or the state. If you consider the Geo should last several years longer than an outside AC or heat pump, it sounds like the Geo will provide the lowest cost of ownership even without considering the savings of electricity. Cheaper electric bill would be icing on the cake.

Brian,

Although I prefer a different ICF, I choose Waterfurnance and have been very pleased. Waterfurnace is well documented which was important to me with a long history of success. I also utilized approximately 1000 square feet per ton - but believe it or not -- I did electronically (thermostat) disable both my emergency backup heat and my second stage as well. Why? Because the system never takes more than a few minutes to hit the setpoint with the first stage so getting there really fast is a waste of energy. Like speeding toward a red light only to stop.

My pricing was somewhat less but it was a few years ago. I have been operating at 1.6 cents per square foot (per month) for three years (heating and cooling separately metered). My target was 1.0 cent (per square foot per month) but it was my first house -- I envy you building a second as I've learned a great deal since then and believe i could hit the target today.

It kills me when I see a house built conventionally with Geo. Heaven forbit BAT insulation. They will have enough up front cost for the extra tonnage sometimes to pay for the ICF entirely. Although, I feel strongly that Geo does not work without ICF -- Solar does not work without Geo. Synergies are important. ICF does really make sense (energywise anyway) without a foam attic, SIPS attic , or ICF attic.

I agree with tb1472000 above regarding cost but with ICF and a good attic as a given -- you do have an interesting situation because your consumption will be so low that your payback time will be extented. For example, if you operate at 2 cents per square foot your talking about $60 per month compared with perhaps 4 cents or $120 for conventional HVAC again utilizing ICF and a good attic. Typical conventional performance in Texas for stick is about 10 cents. Regards.

Posted By TexasICF on 03 Nov 2010 01:45 PM

I have been operating at 1.6 cents per square foot for three years (heating and cooling separately metered).

Heating and cooling, both? Average for the whole year? Can you be a little more definitive in just exactly what the 1.6 cents represents? I'd like to make a comparison to my own house. What's your power rate, cents/kwh, approximately. Idaho Power rates here are on a sliding scale so it's difficult to quote an accurate number. What about yours?

Is your DHW included in the heating/cooling cost? How does the rest of your power bill compare to the heating/cooling portion, total kwh-wise. The reason I ask is that in a well insulated and air tight home the heat generated by life activities, TV, computer, cooking, etc., can be a significant contributor to the total heat input into the home. In my case the daily kwh use during April and October, when the heat pump is doing very little, if any, heating or cooling, is about one-half of the peak summer or winter usage.

Posted By brianpk1 on 02 Nov 2010 03:12 PM
I'm in the midst of my second ICF build.  The first was in the upper midwest, this is in the south.  2600sqft, full ICF (foxblocks), full basement.  I can't decide if the upcharge for GEO is worth the payback even with the 30% uncle sam giveback.  Looking at costs, I hae been quoted $39K for GEO (3 ton waterfurnace) 25K for conventional.  Systems include trane electronic air cleaners, renewaire air to air exchange, renewaire ultra quiet bathroom fans.

Does anyone think these prices are out of line?  Please express your opinions on the subject as I am closing in on teh first pour and need to get the penetrations sleeved before proceeding.

Have you had your HVAC contractor do an estimate of the cost of heating and cooling for your house? If he is using Wrightsoft, or something similar, to perform your heat & cool load calculations, the program can also generate a cost of operation estimate. Using that you can make a more informed decision about which way to go. What you don't want to do, obviously, is to buy a Mack truck to haul sand for your kid's sandbox when a wheel barrow is adequate.

I believe there is no better heating system available than geo, but will the payback be there? If the heating & cooling load is low, then probably not. If your proposed system involves a lot of ducting take a look at the Daikin or Mitsubishi air to air split system heat pump. It involves running refrigerant piping to each indoor unit. May be less costly even than the conventional system you're looking at. Not sure what the rebate situation is though for the mini-splits.

I think the $39k for geo for 2600 sq ft is in line. I paid something on the order of $25k to $30k for a Daikin 3 ton air to air sytem, with limited ducting installed, for my 2000 sq ft house. That included an Ultimateair ventilator ducted to also provide bathroom ventilation. You may not need the electronic air cleaner in an ICF house, unless there's a medical necessity for it or you like to have window open a lot. We live in dusty SW Idaho and have almost zero dust in our house because the house envelope is so tight. The downside of having such clean air all the time is that it is a real disincentive to opening the windows to let in cool spring and fall breezes!

Posted By TexasICF on 03 Nov 2010 01:45 PM

Although, I feel strongly that Geo does not work without ICF -- Solar does not work without Geo.

I'm sure you've read the many comments in other posts expressing just the opposite. If you are going to have a house that consumes a lot of energy, then low operating costs become the main driver, hence the benefit of geo. If the house is a low energy consumer, then recovery of the capital costs become the driver and operating costs are less of a factor, hence geo can sometimes be hard to justify for an ICF house.

If the payback is there, I believe solar can be incorporated into any heating system. Obviously, a system that uses water as its main medium can adapted to solar the easiest. I'm even toying around with the idea of using solar to boost the performance of my Daikin air-to-air heat pump system.

dmaceld,
Sorry not to be clear -- I am referring to cost per square foot per month. Thus, 2 cents per square foot on a 3000 square foot house would be $60 per month (heating and cooling only).

I utilize geo to assist with hot water -- i have a gas tank. I am paying about 11 cents per kilowatt hour. My whole house breakout is as follows 1/3 heating and cooling, 1/3 pool, 1/3 lights and etc. etc.

Regarding the geo with or without ICF... Above you say "If you are going to have a house that consumes a lot of energy" --- this is key. Why have such a house in the first place where the cost of geo will be almost double before you even get started? You'll need the tonnage to overcome the thermal envelop? 1st you fix the envelope - then you get the geo. Solar powered bilge pumps are nuts if you haven't first fixed the leaks in the boat.

Basically, these folks are saying that saving half a big amount is better than saving half of a small amount. So if your bill is $1000 per month its better to save $500 and pay $500. As opposed to haveing a $500 bill and only saving $250 and paying $250. The best green dollar is the one you don't spend. What does that mean? Basically, with ICF and a good attic, you can get into geo for roughly the same budget because you're buying half as much of it. Solar is more of the same -- if you're buying solar panels without geo - it just doesn't make sence. I don't like solar if you don't have the synerigies of icf and geo. And well, wind is the similar.

brian.....are you an O/B or do you have a GC building your house?

I am the general, hiring all trades as req'd.

What state are you building in? Here in SC the local rates for electricity are low enough, even if they went up 10 cents, that the payback for geo would be longer than the unit life expectantcy. It's a sad state of affairs when it is less expensive in the long term to be less energy conscious, but an ICF house in SC will still have low power usage with conventional heat pump.

Ok - experience in Europe has taught me that the mat type geothermal can potentially be a nightmare - and that the bore-hole type are a lot safer in terms of maintenance - although you need to oversize to allow for a partial cooling over time.

If the mat type springs a leak - you have to dig it all up - at least with the bore-hole one the loop can be withdrawn and replaced.

Personally I have used and really like the Aldes system too - see http://www.ecomatcenter.com/crbst_46_es.html for details - this does heating, cooling, ventilation and heat recovery combined.

Thats my 10 cents worth

Posted By insul8 on 05 Nov 2010 07:41 PM
Ok - experience in Europe ...

Personally I have used and really like the Aldes system too - see http://www.ecomatcenter.com/crbst_46_es.html for details

European page in French, and Google fails to translate into English. Not much use for us mono-languaged Americans! Leads me to believe the product is not available in the US, or do you have a link to a US supplier?

try contacting Aldes US - not sure if they brought this product here yet - they do some heat recovery ventilation http://www.americanaldes.com/system-packages/

Being bilingual certainly helps when gleaning ideas from countries maybe 5 years ahead in terms of building low/zero energy homes :0)

Frances new regulations are for a minimum tested standard of a maximum energy use of 50kwh/m2 per year - or 4.65 kwh/ sq ft . . .