Where to put the Money

George_26

A little background, we have a small ranch less than a 1000 sq ft. Attic has new insulation to R49, walls have no insulation except for being wrap and 1” pink foam when house was resided.. I know I should of did the wall insulation then but $$. My boiler is an 8 year old Burnham 205, I guess about 135k, seems a little big. We had a rough but probably accurate heat loss done of 44k. So do I put the money into wall insulation or do I look to replace the boiler, any suggestions

Brad White_200

Where to put the money? Washington Mutual is out....

Excellent question.

That 1" pink foam and wrap, being continuous on the outside will alone do wonders.

(By comparison: An awful lot of commercial high-rises get by with about that much, an exterior "Densglas" yellow board with that red tape, with an inch if insulation and NO insulation batts between the 6-inch steel studs, believe it or not. The air barrier is what counts.)

Your board and wrap would have an R-value, if over an uninsulated stud wall, of over 8.5.

If you have, oh, 900 SF of such wall and your indoor-outdoor temperature difference is 70 degrees (I have NO idea but work with me here), the wall heat loss would be about 7,400 BTUH.

Say gas for you, $2.00 per therm and your system is working at a true AFUE of 60 percent and 6,000 degree-days, that wall would cost you about $305 per year to heat.

If you were to insulate that wall cavity with dense-pack cellulose (at what expense and disruption as you would be doing it from the inside?), the R-value could be as high as a full 19.5.

(EDIT: Not to say that it is insurmountable or not worth doing, but the added value and cost potential vs. savings potential has to be weighed. Insulating from the inside is often done -even on our house- but it is part of the evaluation process.)

The heat loss for that wall alone would drop to about 3,230. The annual heating cost would drop to about $133 per year, a savings of $172 per year.

If the insulation costs you say, $1.50 PSF plus another dollar PSF for patching and painting, call it $2.50 PSF of wall and 900 SF, that is $2,250. Divide that by the $172 annual savings and you have a simple payback of 13 years. With borrowing costs factored in, this will be longer but with energy cost escalation, it will drop, perhaps the payback stays about the same.

Now, your system: Your 44K heat loss versus a 135K boiler. You call that, "a little big"? Sort of the way Lindsay Lohan is "a little tipsy"?

If your boiler's demise is imminent, there are a lot of nice, small Modulating condensing boilers out there in the 50-60 MBH input range and 95% efficiency. Very good news for you. At eight years, that boiler has bout 15-20 years left in it though, maybe more.

You can make that boiler work for you, but it will take some work. Personally, I would decouple the boiler from the radiation loop.

Use a 4-way mixing valve (Taco i-Valve) and their 700 series outdoor reset controller and follow their instructions. You can reset your boiler temperature within reason, (say 180 to 140 over the outdoor temperature span) and the radiation loop you can reset from 180 down to, oh, 90F for deeper reset. This will save you money in a meaningful way. Run constant circulation and you will know comfort.

There are other ways and other products, but I like the ease of the Taco line; a lot of the thinking is done for you.

Brad

joel_19

????

You did not mention how you are heating your water? with a couple kids and a compact house 35% or so of that gas bill could be hot water.

I agree with Brad decoupling the flow would be great with outdoor reset. another way to do it is with a buffer tank you could use a Super Store or similar indirect and use the Taco/tekmar control to reset the tank itself it would give you very nice long runs which help maximize efficency.

But I'd also be looking at solar or something like that if you have just a stand alone water heater. Here in Mass you can get 3k in tax credits between state and federal to help bring cost down.

George_26

Thanks for the suggestions as of now I'm leaning towards a new boiler after the winter. In the mean time I'm getting an estimate on insulating the walls from the outside. I'm looking in the long run what I will save. By the way the water heater is new,replace the old one after eight years it leak. Once again thanks.

realolman

I suppose

geothermal is a form of solar heat, but in Mass what kind of solar heat would work?

I live in the mts of PA and I can't imagine a solar heating system that would be adequate.

Larry Weingarten

A reason...

... to insulate from the inside, even though it's a mess is that you will be breaking the waterproof layer under the siding a bunch of times when insulating from the outside. Sheetrock is also easier to do an invisible patch with.

Yours, Larry

JJ_4

Insulate from the inside....

I have had this done a couple of times and it really isn't too bad mess wise. They drilled two rows of holes in each bay; one at the top and one 1/2 way down the wall. The contractor took care of the patching and I just matched the texture and repainted...as the places needed repainting anyway. One job was in drywall the other plaster and lath. I would expect this to be under 2K and well worth the comfort and added quite.