Analyzing home heat loss?

[William W. Plummer]

Can someone advise me on how to find out where the heat is leaking out of my home? My heat bills are almost twice what some neighbors claim. $1800 for a 1500 sq ft, ranch house. There is 6"+ of insulation on the ceiling and say 3" (whatever was standard in 1970)in the walls. Several years ago, I reduced the heat loss a little bit by replacing the leaky in-the-slab radiant heating system with perimeter baseboard radiators.

All of the windows have been replaced. I shotgunned the whole place with vinyl, low-E units and have since replaced most of those with Andersen units.

An interesting observation is that the heat use (cu feet of gas) didn't increase during the recent Winter when I has home all day. New England was fairly cold and I had the thermostat up to "normal" everyday. That says to me that the loss is in the boiler, running a lot and being inefficient.

Now, if I talk to my plumber, he says that boilers don't lose efficiency with age. He'll happily put a new one in for $3K, but doesn't think it will result in much less heat loss.

Siding contractors promise much improvement but won't put a number on it. That's about $6K.

The gas company will do an infrared scan for $150 but I'll have to wait 'til Winter. And, the scan will show what we expect -- heat loss everywhere.

So, is there some kind of professional, maybe an architect or professional engineer, that can analyze the situation?

[stretch]

Bill, Is the $1800.00 for the whole year, or just the winter. Do you have gas dryer, water heater and stove? What is your gas consumption on those? A leaking water heater relief valve will give you a high gas bill coupled with a high water bill. Where does your water heater relief valve discharge to?

The problem may be infiltration. Do you have a Jenn-Aire cooktop? I have seen those raise utility bills significantly when used a lot, because they can blow a LOT of heated air out of the house, only to be replaced by cold outside air that needs heated again.

You are assuming that it is the insulation, that may not be the case. Definately go for the thermal scan, it is time to stop guessing and start measuring. Se if the gas company will do a blower door infiltration test on your house.

Stretch

[William W. Plummer]

Thanks, Stretch. You gave me something to look into: the hood over my stove which is vented to the outside. It could be sitting there sucking up heat all day and all night! I think there should be a flapper on it but maybe not.

I have an electric drier but the stove and water heater are gas. I have

10 years of monthly electricity and gas consumption figures in a spreadsheet with graphs. The gas consumption decreases to almost nothing during the summer months. The electricity use is fairly constant all year 'round.

One other clue is the house tends to get ice dams even though I have soffit and peak vents. That suggests the ceiling insulation isn't working well. I'm thinking of having more blown in just to eliminate it as a problem.

[bbq]

Are you sure your neighbour nows what he is talking about? Many gas companies lets you have "Equal billing" plan. That is when you pay all year round let's say 200$ and then in September they adjust based on your actuall gas meter readings. Now maybe you are comparing his plan with your actuall usuage plan? I had this happen to me when neighbour was talking about his "lower" bill. It is lower in winter, but then in summer when I don't pay anything, he still pays same 200$. Just another thing for you to look into.

Regards

[barry]

I'd suggest that the ice dams indicate sealing problems between walls/ceiling and rafter area. There should be continuous insulation coverage of course. Sealing is most simply accomplished with continuous vapor barrier inside, in addition to sealing wall cavity from spaces above.

'70s-vintage insulation in walls might be due for upgrade. Depending on where you are in NE, may be well past due. From inside, then proper vapor-barrier and wallboard.

May sound like big-deal. Not really, IMHO, doing one room at a time. Besides, damage that can be done by ice-dams can be a really big deal to repair.

Once that's sorted out, you can get an approximate idea of furnace/boiler efficiency by checking its exhaust temp. Higher temp means lower efficiency. Competent local tech should be able to help here. There are ways to boost efficiency of gas appliance, via stack damper, pressure regulator, etc. Which may even be useful to you.

HTH, John

[Joseph Meehan]

....

Could also mean warm moist air is leaking into the attic. This could be bath vents or many other areas. The blown in insulation can help seal the air leaks as well as add insulation.

[Jim R]

Just be careful the blown-in insulation doesn't block the soffit vents. Unobstructed air flow from soffit to ridge helps maintain uniform temps on the whole roof deck in the winter, reducing the occurence of ice dams.

[m Ransley]

Where do you live, what Zone, what are temp lows. Is bill for1 month. Has boiler been cleaned and flame adjusted.

6" insulation is apx R 21. The N.East probably has a attic code of R35 and optimal of R 60. A blower door test and IR photo would help as a start. But your attic sounds way low.

[William W. Plummer]

Good point, Jim. I'm going to try buying some of the Styrofoam inserts that channel the air from the soffits right next to the roof. But with the slope of the roof, they might be really hard to put in place. Maybe I can pull off the soffit covers and work from outside.

Because ice dams also form over my garage and that is "unheated", my problem is not due to air leaking from the walls up to the attic. But it seems to say that heat is getting into the attic and is circulating.

Blown-in pink stuff certainly helped my first house back in the '70s. The heating costs dropped in half!

[William W. Plummer]

I live 30 miles northeast of Boston. Can you direct me to a web site that has the insulation requirements? I always wonder what the point of dimishing returns is.

What do you think the IR photo ($150) will show? I assume the windows and doors will light up, and the roof, but that's what you expect.

I have a hotwater boiler for the heating system. Does that have a "blower door" to be tested? I think what I should do is ask heating contractors, "What tests do you do when you evaluate a heating system?" Most of them say, "Efficiency." But they can't explain what factors influence it and end up recommending a replacement. The guy I use now doesn't do that and says that it wouldn't help much! Who do I believe?

[L. M. Rappaport]

On Mon, 02 May 2005 19:51:04 -0400, "William W. Plummer" wrote (with possible editing):

I think Ransley's numbers are good. Fiberglass nominally has an R rating of 3.5 per inch. 6" is, therefore 22. Until you get to 60 you can just keep adding more, PROVIDING that you don't block ventilation under the roof. That ventilation, btw, will also lengthen the life of your roof shingles by providing cooling to them in the summer. In northern NH, the cheapest insulation is blown in cellulose which is fine for horizontal surfaces like an attic. Usually you buy the cellulose in bales and get loaned the machine to blow it in.

I have no idea, but it is money well spent. That will help you KNOW if and where you have a substantial energy leak.

Usually, they use a meter which measures the temperature and composition of flue gases. The idea of efficiency is just to determine how much of the potential energy of the fuel is converted into heat. It does not tell you anything about the efficiency of your home. One thing which will make a small difference is to use a pipe to bring in outside air for combustion, rather than using the air present in the home, since that air is ultimately vented outside through the stack.

Well the difference between normal efficiency and poor is only a few percentage points, so you can judge for yourself.

If it were me, I would most certainly have the IR study done in the winter with the house in normal configuration. Your heating bill sounds quite high. Mine is higher, but I am just a few miles south of the Canadian border and the house is 8000 sq. ft. with a heated garage. FWIW, there haven't been many changes in insulation technology between 1970 and today. The principles remain the same: keep water vapor out and the more, the merrier!

[Goedjn]

Umm.. sort of.. The bottom line is, you can't save more in heating bills than you're spending. So you figure out how much you're paying in heating bills, and which surfaces account for how much of that. If you can double the insulation in any given area, you halve the heat loss there. That gives you dollars per year saved. Multiply that by how long you expect to live in the house, or 20 years, whichever is smaller.

If you can double the insulation for that price or less, then it makes sense to do so. If you can't, it doesn't.

If there is ANY connection between the attic spaces and the living spaces; a door, a hatch, can-lights, balloon framing, then think carefull about blown-in cellulose. It will *NEVER* stop sifting dust into the rest of the house.

[William W. Plummer]

Another lead! I have a dozen can lights. However, I've been told it is against Code to have insulation in contact with them. I have a bias against cellulose and would probably have pink stuff blown in. I know isocyanate foam is bad because it will push the siding and wallboard off the studs. Is there another choice?

Thanks.

[Goedjn]

Depends. Are you insulating walls, or an attic floor? If the former, you've either got to rip them open, or spray/blow something in. Chunky stuff like chopped fiberglass leaves gaps, cellulose is dusty, foam risks popping your walls. There's low-expansion foam, and if that's put in by competent professionals who aren't being rushed, the chances are that it won't hurt your house any, but that's likely to be your most expensive choice.

I suppose, if you can get at the framing beforehand, and seal up all the cracks and penetrations beforehand like it was the hull of your new submarine, cellulose might work, but my experience with a 40 foot high timber/ballon-framed hybrid with cellulose blown in by a roofing contracter has made a serious negative impression.

[ds549]

plummer said that his gas bill is the same in summer and winter. wouldnt that point to a problem with the gas fired boiler??? lucas

[stretch]

1) In spite of other posts, celulose is better insulation than fiberglass.

2) Can lights are a hole in the ceiling. I have done blower door testing, you can't believe some of them are. Not all are however. Some have nearly air tight housings. The best ones have lenses and gaskets to reduce air flow into the attic. If you can retrofit with those it will help. Do you have any air conditioning, that can affect air pressures and infiltration in the house.

3) Icynene foam is good, but like any foam expansion can be a problem. Best to ask an insulation contractor. It depends what he is used to and what he is best at. Some may have special equipment for a certain insulation that makes it easier to apply in certain circumstances. But get the IR test first so you are not guessing any more.

4) Get the blower door test also, unless you find a BIG problem with the IR test.

Stretch Certified Residential Energy Auditor

[Joseph Meehan]

Actually he said "The gas consumption decreases to almost nothing during the summer months.

[LB]

Points to a budget plan for his gas.

LB

[William W. Plummer]

Hold it. My electric usage (drier, computers, TV, lights) is fairly constant year round. My gas usage (heating, cooking, hot water) is high in the Winter and drops to almost nothing during the Summer.

Budgeting the payments does not affect how much you pay, only when you pay it. I tried budget payments years ago, but I couldn't convince myself that the gas company was doing it right. The "January adjustment" always muddied the waters. So, I went monthly. And I started recording usage and cost every month. Graphing that in Excel is very instructive.

[ds549]

sorry guys, i must have had a blonde moment during my last post.. lucas