1. ATTENTION returning members. If you are coming here from the old forum for the first time, you will need to reset you password. However, we had an email problem getting password reset links set out to a lot of the email addresses. That problem is temporarily rectified but IF you still have an issue, email me direct at info@thebuildingcodeforum.com and I will give you a temporary password.
    Dismiss Notice
  2. Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by clicking here: Upgrades
    Dismiss Notice

2015 IECC/IRC Mandatory Blower Door Testing

Discussion in 'Residential Energy Codes' started by Coder, Dec 15, 2016.

  1. tmurray

    tmurray Sawhorse

    Joined:
    Jun 10, 2011
    Messages:
    1,038
    Likes Received:
    166
    The homes you typically build would be in the 3 to 4 thousand range based on the increased labour and ductwork. I just installed one in my home a couple years ago for a thousand dollars. 2600 sq ft 2 storey. I did all the work myself, so that's only material costs.

    The big thing installers need to understand is that even though houses are getting bigger, families aren't. The same ventilation for 4 people is needed regardless of the size of the building. The only thing that changes is the ductwork and labour to install it.

    The downside with HRVs and ERVs is the same as any mechanical system: they work great until you turn them off. People don't understand them and think they are a waste of money and then turn them off. I've been to a couple houses with indoor air quality issues and the first thing I noticed in them is that the owner turned off the ventilation system to save money.
     
    JBI likes this.
  2. conarb

    conarb Sawhorse

    Joined:
    Oct 22, 2009
    Messages:
    2,776
    Likes Received:
    157
    Yeah, a mechanical contractor I know told me that a tract builder installed them and he had disabled most of them in the entire tract, people paid him a couple of hundred a house to disable them because they were so expensive to run, so what's the purpose of sealing-up homes if it costs more to operate them than normal homes? I remember Panasonic arguing that with volume that the price would come down, so early adopters would pay more but later they would become more economical, kind of like the arguments for solar panels today
     
  3. mtlogcabin

    mtlogcabin Sawhorse

    Joined:
    Oct 17, 2009
    Messages:
    6,373
    Likes Received:
    364
    1200 sq ft home about $800.00 for a cheap one $2,000.00 for a good one plus installation is what the HVAC contractors tell us. Then again we are building homes for $85.00 per sq ft and up
     
  4. conarb

    conarb Sawhorse

    Joined:
    Oct 22, 2009
    Messages:
    2,776
    Likes Received:
    157
    It just shows that like fire sprinklers a manufacturers' coalition can get their products required in the codes whether they work or not. What's wrong with opening windows? This customer with his mosquito problem is the first I've had to refuse to open windows, he didn't want to pay or listen to a 1,250 CFM roof mounted fan to extract the moisture, he sure wouldn't want to pay for a several thousand dollar ERV, I guess you guys use HRVs in cold climates and ERVs in hot climates? Where do you draw the line? I was talking to another contractor and he said before his customers move in he tells them: "For Christ's sake, keep you windows open, this is a sealed-up house."

    I think my mechanical engineer customer proved that little "fart fans" are worthless, getting up in the middle of the night to take pictures and then taking pictures again in the morning.
     
  5. tmurray

    tmurray Sawhorse

    Joined:
    Jun 10, 2011
    Messages:
    1,038
    Likes Received:
    166
    Costs about $42 a year if they are on constantly. Most would be less than $20 a year. It's more about how wasteful the old air exchangers were and people not understanding the difference.
     
  6. tmurray

    tmurray Sawhorse

    Joined:
    Jun 10, 2011
    Messages:
    1,038
    Likes Received:
    166
  7. tmurray

    tmurray Sawhorse

    Joined:
    Jun 10, 2011
    Messages:
    1,038
    Likes Received:
    166
    There's nothing wrong with opening windows. I completely agree with you there. The issue is that people don't do it.
     
  8. conarb

    conarb Sawhorse

    Joined:
    Oct 22, 2009
    Messages:
    2,776
    Likes Received:
    157
  9. tmurray

    tmurray Sawhorse

    Joined:
    Jun 10, 2011
    Messages:
    1,038
    Likes Received:
    166
  10. conarb

    conarb Sawhorse

    Joined:
    Oct 22, 2009
    Messages:
    2,776
    Likes Received:
    157
    That worked, that's a HRV, what it it's 100° outside? How does an ERV work and when do you use that? In moderate climates do you install both a HRF and an ERV?

    A lot of commercial buildings from the 70s have no openable windows and constant blowing air, I have an engineer located in one of those and I hate to spend time with him with the constant air blowing, I once belonged to gym and they had three of those large 3' diameter fans behind the stairmaster section, women were constantly turning them on and men were constantly turning them off, one guy announced that he was quitting and joining another gym, I asked him why and he said: "One word, fans", I understood.
     
  11. tmurray

    tmurray Sawhorse

    Joined:
    Jun 10, 2011
    Messages:
    1,038
    Likes Received:
    166
    HRVs just recover sensible heat - the heat that shows up on a thermometer - ERVs will recover both sensible and latent heat - basically humidity. Generally you guys would be looking at ERVs there and we keep our HRVs up here. The house here that recently blew a .5 ACH has a unit that is on most of the time. It is a low velocity unit that you cannot hear (I'm only 31, my hearings still fairly good) and cannot feel a draft. it's a lot more expensive that the unit I showed your, but even those units aren't really noisy. When I'm doing a final inspection I can turn one on and you can hear it if you try to. As far as a draft, you won't feel one unless you hold your hand within a couple inches of it.
     
  12. tmurray

    tmurray Sawhorse

    Joined:
    Jun 10, 2011
    Messages:
    1,038
    Likes Received:
    166
    As far as where the line is...I don't know. Someone who is much smarter than me will probably dream up some way of figuring that out, but it's probably the same line where you switch the vapour barrier from the inside of the house to the outside.
     
    #52 tmurray, Aug 4, 2017
    Last edited: Aug 4, 2017
  13. Paul Sweet

    Paul Sweet Sawhorse

    Joined:
    Oct 17, 2009
    Messages:
    817
    Likes Received:
    78
    How many HRVs & ERVs will last the life of the house? Anything mechanical fails after a while, and few will be repaired when they do.
     
  14. tmurray

    tmurray Sawhorse

    Joined:
    Jun 10, 2011
    Messages:
    1,038
    Likes Received:
    166
    We have companies that just do that. We aren't a large population area by any means, about 20000 people. He have a contractor with a couple employees who just do replacements.
     
  15. conarb

    conarb Sawhorse

    Joined:
    Oct 22, 2009
    Messages:
    2,776
    Likes Received:
    157
    It appears that most of these energy and green requirements drive maintenance costs up, insulated homes rot out a lot faster than uninsulated homes, multi-pane windows have to be replaced an average of every 20 years, I had a friend tell me that he was spending an average of $6,000 a year replacing the IG units in his 20 year-old home, he asked if they were saving that much energy? I had to tell him no, that multi-pane windows don't save money, he is spending money to "save the planet".
     
  16. tmurray

    tmurray Sawhorse

    Joined:
    Jun 10, 2011
    Messages:
    1,038
    Likes Received:
    166
    That's really easy to say when you don't live somewhere that when people buy one of the uninsulated homes, they have to choose between being hungry or cold.
     
    JBI likes this.
  17. steveray

    steveray Sawhorse

    Joined:
    Nov 25, 2009
    Messages:
    5,125
    Likes Received:
    443
    Don't buy the uninsulated home?.....The biggest part of the energy code I agree with is the posting of the predominant R values....At least that way people can shop apples to apples...
     

Share This Page