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What techniques and methods can be used to test a building envelope for air infiltration/leaks? I know about the blower door thing, but I’m more thinking in terms of methods that don’t require special equipment, or other than readily available materials. I have seen references to this here over the years, but never a discussion of it as a topic. My interest centers more around what can occur during the new home construction process, but I would imagine that at least some of the same techniques would be universal between construction and after the fact problem diagnosis.
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How other than by presuriziation or depressurization could you test this in any quantifiable manner?
*Bill:I don't know. That's why I asked the question. Could bath fans, a cloths dryer, or kitchen exhaust hood be used to depressurize a house? I guess what you are saying that it has to be measured. I assume you use a barometer to do the measuring? But I guess you also need to know how many CFM of air your blowing in/out. I'm just not entirely comfortable with taking steps a, b, c, & d to build a tighter house but never really knowing if a, b, c, & d made much difference.I do really like Fred's advice (below)... start by looking for the big holes.Fred:Can you give a few examples of what the fist sized holes were that you reciently found in these people's house?
*FWIW, a very rough way to access is to use a draft guage in the furnace or water heater flue and have someone open and close an exterior door.I've found that in older, pre-70's home, the ball will barely move, if at all, when the door's opened and closed, but in newer homes, it will usually jump a noticeable amount before returning to the original location.This would just be a starting point, of course, and is hardly definitive or quatifiable.Bob Walker
*I made a huge improvement in our old house following Freds advice on this - my wife and kids could feel the difference almost as fast as I plugged up the tops of balloon framing bays on a very sub-zero night.Fred has explained a method of a BD using less sophisticated tools - basically using fans and measuring pressure changes between changing openings of a known size. You could measure the change of pressure from opening a window of 4 sq ft - for instance - and roughly graph the results. You would need a decent manometer( you must have missed the barometer posts) but that's less than $100 last I looked.
*Big holes:I just spent a couple of days last week plugging a chimney chase that you could fit three people into. The more I closed it off, the faster the warm wind came wistling through the remaining bits. In addition, this client's house had all the perimeter balloon-framed walls dumping into the vented attic, as well as all the interior partition walls. I had her pull up the existing fiberglass, stuff it into polastic bags, and stuff those bags down into the tops of the balloon framed walls. That night she said the draft around her ankles was gone and her feet weren't freezing like they usually were. And this was with no insulation in the attic. Before we started all this, she said that when the furnace shut off she could immediatly feel the temperature drop.And the furnace rarely shut off. And she had huge ice dams backing up into the walls because the snow was melting off her roof from all that heat dumping into the attic. Vents did not help that.Last night we blew in 18 inches of cells. I'll be curious to see what happens to her fuel bills and the ice problem.She's been filling a 275 gallon fuel tank every three weeks to heat 1800 SF to about 60 degrees. Steve
*Fred:Thanks very much for the info and reference to the articles.For anyone else who is interested here is the URL of one of themHow Not to Kill Your Clients by Rob deKieffer published in the Home Energy Magazine issue Dated May/June 1995 It deals largely with problems associated with combustion appliances, namely the release of CO (Carbon Monoxide) and other pollutants into the living space. To me though, it seemed only to deal with the "testing" the aspect as a peripheral subject.I couldn't find a copy of the 2nd article Finding Hidden Heat Leaks by Thomas Blandy anywhere on the web.It sounds like many/most of the large air leaks you describe were due to builders not thinking in terms of "building/thermal envelope during the building process. Bill:A search didn't bring up much about the " manometer".
*Be not jealous, Fred!It was dirty hard work. Especially the part where I was hanging upside down into the chase with not much to keep me from falling to oblivion other than the gripping power of my ankles!But it was gratifying to hear that she felt the results almost immediately.Steve
*Try http://data.oikos.com/products/FMPro?-DB=cat&-LAY=web&-Format=comp_list.html&-Op=eq&cat_find=Air+Pressure+Gauges+(Manometers)&-SortField=Company::SortBy&-SortOrder=descend&-SortField=Company::Company&-SortOrder=ascend&-Error=error.html&-Max=20&-Find for some links.Also, Grainger catalog has them. Perhaps more than I thought - like $200.
*Matt-grab a candle during a windy day. Pass it slowly around penetrations in the building envelope, any air movement will move the flame. I guess you could also blow the candle out and watch the smoke for air currents. During new construction, just watch cracks around door and window frames, pipe penetrations, etc. for loose insulation to be used in. Just don't make a house too tight-you need some fresh air otherwise the burned pot roast on sunday is still there on friday.
*Matt, this is not what you asked for, but something you should be aware of: ultrasonics. In my work I use an ultrasonic gun to detect compressed air and refrigerant leaks. Basically it takes high frequency sound (>20 kHz) that is beyond the human hearing range, heterodynes it, and brings it down to a range that you can hear using the headphones supplied. There is also a "warble tone generator" supplied that emits a warbling, high frequency tone that you can't hear, but with the gun and headphones it sounds like a singing canary. You set the generator down in a room, go outside with the gun, and you will find every crack, no matter how small. The advantage is it lets you isolate the exact spot.Anyone you know who works in maintenance in a medium to large industrial plant, probably has access to one of these. I bought mine on e-Bay for $600. Not something you'd use all the time, but if you're in the home energy business you might want to check it out.
*UEI makes one for 140.00 just got one thru mail order. If you want the mag name email me and let me know. Can't remember name right now.
*lorne l...... u got the generator, the gun and the headphone setup that crusty was describing for $140 ?tell me more...
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What techniques and methods can be used to test a building envelope for air infiltration/leaks? I know about the blower door thing, but I'm more thinking in terms of methods that don't require special equipment, or other than readily available materials. I have seen references to this here over the years, but never a discussion of it as a topic. My interest centers more around what can occur during the new home construction process, but I would imagine that at least some of the same techniques would be universal between construction and after the fact problem diagnosis.