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Blower door demonstration

Greg Swob
Greg Swob Member Posts: 167
Haven't been to SW Missouri in a while or Ark. since '75.
I'd like to go back and do some serious fishing sometime. Here's a website for a 'real' man's sport for you in Northern Texas. www.affordablehoghunts.com Wild pig hunting with a KNIFE! Even my fear no danger brother-in-law thought this was a little too off the scale for him. Greg

Comments

  • jim sokolovic
    jim sokolovic Member Posts: 439
    Saw on \"Home Improvement\" repeat on T.V....

    this weekend, the Blower Door test that Mark Hunt had referred to many times. Does someone really go around the whole outside of the house with a smoke gun? Heidi "the Toolgirl" made the presentation doubly-delightful (DD)!
  • Greg Swob
    Greg Swob Member Posts: 167
    When Hollywood gets involved, things can get a little twisted.

    I enjoyed the show Home Improvement, too. However, when
    performing a blower door test, we do not go around the outside of the dwelling, but rather inside each room. Using a smoke 'puffer', smoke matches and even just a bare hand, leaks can often be readily detected. The contractor who performs your test should have a preparation list for you. Things to prepare would include: clean ashes from fireplaces and do not have any fires burning; shut off furnaces, water heaters and other such combustion appliances and/or lower T-stats so should the interior temperatures be reduced, heating appliances will not turn on; form a list by thinking where you may notice drafts in the home, etc. We virtually always use an Infrared (I.R.) camera in conjunction with a blower door test and provide a VHS tape recording of the I.R. view in each room of the home. The I.R. 'sees' heat and cold areas show up clearly, leading one to find leaks readily also. Blower doors will not hurt your home - a contractor who builds energy efficient homes told a client that "...this house is so tight, the blower door will rupture your windows..." That is just plain rubbish - it may draw some ashes from inside your fireplace, however! The effect of the blower door is so minor, feel free to walk around the home during the test as you normally would. Find a capable contractor and prepare to learn some secrets of your home's envelope. Greg
  • Mark Hunt
    Mark Hunt Member Posts: 4,909
    I like that!


    Hollywood!

    We depressurize homes and test from the inside. A smoke pencil is used sometimes, but many of the air leaks can be felt.

    Stack effect is a huge portion of heat loss in a dwelling and it is also THE cause of dryness in a home in the heating months.

    A comprehensive test of any home can identify the places where your money is floating out of the home.

    Mark H

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
  • Greg Swob
    Greg Swob Member Posts: 167
    Right you are!

    Insulation is so important, but is often over emphasized as a cure to all ills regarding energy consumption. Just as wearing a nice thick warm coat on a cold windy day won't keep you comfortably warm if you fail to zip or button it up. We virtually give away the blower door tests and still have a difficult time getting people to have it done. I did my own home and found it to be too tight, which we were pretty well aware of already. Added an HRV and the girls seem to have less 'allergy' troubles. Being made of SIP's the I.R. view was pretty boring - no studs in the walls to show up, just a plain whitish light gray all-over appearance until one came to a window, then black (cold). It's cool running the camera looking at all the studs, then suddenly finding a cavity with missing or settled insulation. We've probably killed a few insulation contractor sales, but that is not always what homes need. So often just a few tubes of properly placed caulking, weather stripping, door sweeps, closing off pet doors, etc. go a long way to making major comfort improvements. Then sometimes, along comes the associated problems of tightening up the home too much. That's when the blower door will tell you if an HRV is absolutely essential or just advisable. Greg
  • Greg Swob
    Greg Swob Member Posts: 167
    Right in the middle of the continental USA

    Kansas. But I always tell people we live right in the middle of the BEST fishing in the country. All those Minnesota lakes are just a few hundred miles away, Lake Texoma is about the same distance, but opposite direction, either Ocean is just about equally 1,700 miles away; Canada is only a 1,000 miles away, Gulf of Mexico is... Greg
  • Dave DeFord
    Dave DeFord Member Posts: 119
    And not too far...

    from northern Arkansas where the last two worlds record brown trout were caught. And, for those that care some of the best bass fishing in the world is on the impoundments in southern Missouri and northern Arkansas.
  • jstrocky
    jstrocky Member Posts: 2
    water velocity

    I need to flush out some heating pipes to spec 6 feet per second and prove that the flow is 6fps does anyone know of a flow meter that will measure this and where to obtain one?
  • Chuckles
    Chuckles Member Posts: 14


    We paid $300 for a blower door test because gas consumption in the old house we just bought was high, about 14 BTU/sqft/degree-day. Very interesting and educational; we had leaks equivalent to about one air change per hour, lots of air rushing into basement and finished attic under blower door conditions.

    My claculation (using heat capacity of air) suggests that if we could bring air exchange down from 1 change to 0.5 changes per hour, we should cut our gas bill ~15%.

    We closed up all significant leaks with expanding foam, caulk, weatherstrip and so forth, but there was NO difference in the therms used per degree-day. None, zip, nada. We've now spent a total of $500 on this with no benefit.

    What might explain this?
  • jim sokolovic
    jim sokolovic Member Posts: 439
    Are those areas...

    that you did most of the sealing (the basement and attic) unheated and normally closed off from the main area of the house? There had to be some benefit, at least in the drafts felt there, or maybe poor insulation is your main culprit? How come no one's talking about Heidi?
  • Chuckles
    Chuckles Member Posts: 14


    The attic and basement are closed off now, they weren't before. No difference.

    As for Heidi, I haven't watched the show, but I guess I'm going to look for it now. I should TiVo it so I can play it back repeatedly in slow motion. To see the smoke trails, I mean.
  • Dave DeFord
    Dave DeFord Member Posts: 119
    Actually I'm in

    Michigan. My folks grew up in and around KC and moved to Michigan when I was very young. They then retired to Fayetteville AR about 1985 and abandoned me in Michigan. I used to try and get down there at least once a year until my dad died about 10 years ago. Mom moved back to KC when she remarried a couple of years later. It is one of my favorite parts of the country though. As to the boar hunting with a knife I'll pass. I don't even hunt the deer in my back yard.
  • Greg Swob
    Greg Swob Member Posts: 167
    I have an aunt & uncle in Flint, MI

    > Michigan. My folks grew up in and around KC and

    > moved to Michigan when I was very young. They

    > then retired to Fayetteville AR about 1985 and

    > abandoned me in Michigan. I used to try and get

    > down there at least once a year until my dad died

    > about 10 years ago. Mom moved back to KC when she

    > remarried a couple of years later. It is one of

    > my favorite parts of the country though. As to

    > the boar hunting with a knife I'll pass. I don't

    > even hunt the deer in my back yard.



    The most beautiful country I can recall seeing.
  • Greg Swob
    Greg Swob Member Posts: 167
    I have an aunt & uncle in

    Flint, MI. We haven't been up there for almost 20 years!
    Man, time goes by. Sandy was 6 months along with our first daughter then. That is beautiful country. Toured an old German community, wineries, covered bridges,...
    Greg
  • You Missed A Big Part of the Blower Door Test

    We do blower door testing and weatherization. What your first test told you is, where the biggest/easiest leaks were. You sealed them and think you have the leaks fixed. All you did was seal the ones that were the easiest to find. Air takes the path of least resistance. Now that you have sealed them up, get another blower door test, to find the rest of them. Ideally, we run the blower door, find all we can find, fix those leaks, then run it again, find some more, fix them and on and on, until we get a blower door test that shows we really slowed the air infiltration down. You can do the same weatherization with any fan that will push a lot of air. Just rig it up to blow air out of the house, and start looking for leaks. Do it on as calm a day as possible, and with realtively cold temperatures outside. That make it easy to feel the cold air coming in. Once you have found and fixed everything you can feel, have the blower door test done again to verify you got most of them. I will caution you, many leaks will be in areas that may be difficult to reach or see, ceilings, attics, crawl spaces. So, "Think Like a Leak" Good Luck!
  • Duncan_9
    Duncan_9 Member Posts: 33
    Convective air movement.

    What do you mean the attic and basement are closed off now, they weren't before? Closed off from what?

    I'm thinking about moisture problems, What part of the country are you in?

    I noticed you said "old" house. What are the insulation levels and types in roof, floor and walls?

    What type of construction (lap siding, maybe)?

    Did the blower door guys point out things to you like plumbing chases that extend from basement to attic?

    Kitchen cabinet soffits?

    There are ways outside air movement can scrub heat from walls whose inside surfaces are warm. Even though no actual outside-to-inside air exchange takes place.
  • Mark Hunt
    Mark Hunt Member Posts: 4,909
    Chuckles


    Could you tell me what the CFM50 number was when the blower door test was performed?

    Also, square footage and volume of the home?

    Outdoor temperature when the blower door was done as well as indoor temp.?

    Number of stories in the home? Number of people? Number of bedrooms?

    What part of the country are you in?

    The shell contractors that we work with will run the blower door frome time to time while they are doing air sealing work. This lets them find the "invisible" leakage.

    Mark H

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
  • R. Kalia
    R. Kalia Member Posts: 349
    why didn't I think of that?

    >Now that you

    > have sealed them up, get another blower door

    > test, to find the rest of them. Ideally, we run

    > the blower door, find all we can find, fix those

    >. then run it again, find some more, fix

    > them and on and on, until we get a blower door

    > test that shows we really slowed the air

    > infiltration down. You can do the same

    > weatherization with any fan that will push a lot

    > of air...


    Now that I read this, I feel stupid for not having thought of it. The blower door guy did say he would come back after I fixed the leaks, but actually, I do have a fairly strong Lakewood window fan we use in summer as a whole-house ventilator. I ran it today and indeed there are still a number of leaks. I will seal and repeat, and when I can't do any more with my fan, I'll have the blower door people come back with their more powerful fan.Thanks for the advice!
  • Boiler Guy
    Boiler Guy Member Posts: 585
    Leaks & more leaks

    I had a test done about 6 yrs ago 1976 split level home in western Canada. I think the builder forgot to attach the two levels together. Found some very interesting stuff with depressurization. This project required MUCH MORE than just sealing. Fixed all the big leaks- retested - fixed all the not too big leaks - retested - 5 times to get it right! You would be surprised at the leakage through poor quality vapor barriers!!! Lots of work! However, there comes a time when it just might be beyond thye best of intentions. Good Luck Howling in Winnipeg
  • Mark Hunt
    Mark Hunt Member Posts: 4,909
    You need to know


    what he target number is. You could seal the house to the point where mechanical ventilation is required.

    Is that likely? Probably not. Possible? Yes.

    Another thing to remember is that when you start tightening the house up, you have changed the dynamics of the home. So where there were no draft problems with atmospheric equipment before, you may now find that when the clothes dryer runs the water heater won't vent properly. I have seen this happen.

    When you change one thing in your home, you affect the entire home.

    Make sure a worst case depressurization test is performed to assure that your combustion appliances will burn and vent properly AFTER the sealing is done.

    Mark H

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
  • R. Kalia
    R. Kalia Member Posts: 349
    perhpas I should mention age of house

    > what he target number is. You could seal the

    > house to the point where mechanical ventilation

    > is required.


    House (brick) was built 1922. I am not going to worry about over-sealing it; if I somehow manage to go below 1/3 changes per hour, it'll be the most airtight house of its age group in the country! But I will have the blower door people come back at the end, to make sure.
  • Mark Hunt
    Mark Hunt Member Posts: 4,909
    Good idea


    But please remember to have a combustion and draft test done as well.

    It is very important that you have this done as well.

    Mark H

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
This discussion has been closed.