[Greenbuilding] Green real estate market -- spray foam, and geothermal

[Keith Winston]

Hi Steve,

Geothermal equipment is typically considered to last about twice as long 
as air-source equipment. The reason for that is, there is no outside 
unit taking the weather directly, and the temperature swings the units 
are handling are much more controlled. I would readily expect a good 
well-installed geothermal system to last in excess of 20 years. There is 
quite a range in quality and performance out there, though, so don't get 
into a system you'll regret later... All that said, I've abandoned 
geothermal on a string of projects due to outrageously high bids. If you 
are using geothermal in an open-source arrangement, drawing water from a 
well and the discharging it, the water quality can often lead to 
increased equipment wear.

All (professionally installed) spray foams are, to my knowledge, 2-part 
polyurethane foams. Many foams are sold as such, and biobased/soy are 
just 2-part PU with some portion of the polyol part replaced by 
vegetable-oil-derived polyols, amounting to 10-30% of the final product. 
I believe Icynene is an open-cell polyurethane. All the foams are fairly 
horrific in terms of safety/exposure during installation (they require 
using an external-air breathing apparatus, for example, not just a 
respirator), but most sources suggest that they are largely vapor-free 
after they've cured, in a few days. Many of them used to use terrible 
blowing agents, I'm not sure that any of them do now. Many people think 
about oil-based polyurethane floor finishes and shudder with dread at 
using them, but water-borne polyurethanes (which includes sprayed) don't 
have the same nasty solvents.

The reason for foaming is to air seal, as much as to insulate. Foam is 
sold more or less by the board foot, installed. So you could have them 
spray 1-1.5", and then finish out the insulation with batts or blown 
cellulose (either wall-spray or dense-pack, I'm inclined to believe that 
dense-pack is a little harder to do right and wall-spray takes more 
equipment). You can also foam yourself, for a little bit less $ per 
board foot (that is, your labor doesn't save much money, except on small 
jobs or otherwise where you get very high bids), using the tigerfoam.com 
products (or other foam kit products, i.e. foampower.com), which seem 
interesting to me but I haven't used them yet. Tigerfoam has very 
helpful technical support. My major concern is the blowing agent which 
is an HFC refrigerant, R134a. It has 0 ozone depletion potential, but a 
relatively high greenhouse gas global warming potential (GWP) of 1300. 
The material data sheets specify a total percentage as high as 20% (10% 
A, 30% B), and a two-tank system at 39 lbs/tank would then contain 7.8 
lbs R134a. With a global warming potential of 1300, that would equate to 
7.8*1300 = 10140 lbs equivalent of CO2. That's for 600 bf of foam. 
Yikes. That's about 5 tons, which could be about as much as you release 
driving your car in a year. In an average sized house (let's say 2000 
sf, 10' walls, flat ceiling, 40' x 50' shape) that equates to 3800 sf of 
wall/ceiling area, so if you installed an average of 2" that would be 
7600 bf or about 60 t CO2 equivalent release. Hmmm. I was talking with 
the Tiger foam people today: we should convince them to change to a 
much-lower-GWP blowing agent -- which is not a trivial challenge for 
them, but a complicated reformulation...

The Tiger people had all kinds of bad things to say about open-cell 
foams, btw. I'm not sure I buy it all (permeability can be an advantage, 
if not overdone). I believe all the professionally-installed foams 
(read, expensive equipment required) use water as a foaming agent, so no 
GWP at all.

We just had Icynene blown on a job recently, and it slightly peeled away 
from some of the framing members in some places. Have other people seen 
this? I have heard of the problem before, I suspect it might have been a 
little too cold for installation... I don't think it's going to be a 
problem, but I'd probably try harder to have foam installed in warmer 
weather next time.

Keith





Steve Tripp wrote:
> I have received quite a bit of excellent information from everyone and have
> quite a few leads to follow up on.  I'm pretty new to the world of green and
> sustainable living and had not heard of EEMs before.  This is an area I'm
> looking into right now with my bank and Credit Union.
>
> One thing I have noticed after talking to several General Contractors about
> geothermal systems is that there is not a lot of good information out there
> about reliability and performance.  10 years seems to be average that they
> give these systems to last before requiring major repairs.  Our energy costs
> are also quite low compared to other areas of the states and makes it more
> difficult to show payback before repairs are necessary.  I'm still looking
> into it though because I don't let go of ideas that easily.
>
> My wife and I are doing most of the finish carpentry, finish plumbing and
> finish electrical ourselves as well as installing the bamboo floors, which
> is as much as I can handle on my schedule, so our sweat equity should be
> pretty considerable on this remodel.
>
> When it comes to low-no VOC products, Contractors seem to be quite well
> versed and have worked with them, which is great.  One thing I'm looking
> into in this area is the spray in foam insulation that expands into all the
> crevices.  It is a very efficient product, but I have not found anything out
> about its chemical makeup.
>
> Thanks to everyone.  The information has been invaluable.
>
>
>
> On 1/10/07, Jason Holstine <jasonh at amicusdb.com> wrote:
>   
>> If you're not going after a jumbo loan, try for a Fannie Mae energy
>> efficient mortgage (EEM). A variety of local and national lenders are now
>> offering them. The program basically counts expected energy savings as
>> income, thus improving your risk score and allowing you better terms.
>>
>>
>> Steve Tripp wrote:
>>     
>>> (I) am wondering what kind of
>>> uphill battle I may have with the bank if I cannot show that we are
>>> adding more to the value of the home.
>>>
>>>       
>> Explain to the loans officer that because you will be spending less money
>> on
>> heating and cooling, you will have more 'discretionary capital'
>> to pay the mortgage with. Of course you will have to have some $ figures
>> on
>> paper to back this statement up.
>> Lenders are in the business of lending money and earning a return on it.
>> If
>> your credit history merits a loan for something like a new car or a
>> snowmobile, there's no reason they would refuse you one for home
>> improvements of any kind, especially if you have some equity in the house
>> and will be adding more via the 'sweat equity' route.. If you can show
>> that
>> the improvements will be the equivalent of getting a salary raise ("A
>> penny
>> saved is a penny earned". said Old Ben ) they should be less hesitant to
>> fork over the $.
>> If not, the next step is: find a new bank or mortgage broker.
>>
>> Regular home construction starts in the US have dropped by something like
>> 13%, and today's Province newspaper, it appears the expectation is that
>> they
>> will drop off a further 11%.
>> The article was talking about this as a sign thee will be a drop in the
>> market for softwood lumber, but the unwritten "other part" of that market
>> change is that there will be more mortgage money floating around looking
>> for
>> some place to go to work.
>>
>> You asked: Do green homes sell?
>>
>> Almost any home will sell eventually, but local market conditions
>> determine
>> when and at what price. However, with the internet changing the world into
>> one big market which individuals can play in, the selling of a green house
>> might best be done on line to reach a market more interested in such
>> things.
>>
>> Here is a link to the archetypal site featuring Green Homes For Sale.
>> http://www.greenhomesforsale.com/
>>
>> In closing, the more of the work on the renovation that you can do
>> yourself,
>> the less money you will need to borrow. That's not always possible, but
>> even
>> just doing the site clean-up and doing things like sorting, de-nailing and
>> cleaning up lumber so it can be used again or recycled elsewhere, and
>> perhaps part of the landscaping work, will save you some money.
>>
>> Cheers,
>>
>> Chris Green.
>>
>>
>>     
>
>   

-- 
Keith Winston
Earth Sun Energy Systems
Hyattsville, MD 20781
301-980-6325
send me mail at 
keith at the company below
www.EarthSunEnergy.com