HVAC bypass damper question

HVAC bypass damper question

James KimPro Member
Investor · Los Angeles · Member since 2021 · 89 posts · 23 votes

Hi,

I'm not sure if this is the right section of the forum to post this question, but wanted to know if anyone has experienced this or have knowledge that they could share with me.

My rental unit is a 2 floor house with separate thermostat on each floor with one HVAC unit. I recently had it serviced (annual) even though the house is a new build (2022). The technician told me that i needed a 'bypass damper' that connects from the return plenum to the supply plenum. I understand that this helps with controlling temperature and air pressure in zoned spaces and the technician also told me this helps prolong the life of the HVAC.  It also appears that a bypass damper is not something that might be 'required', though i may be wrong, and I'm asking the builder if this is something they could come back to install. I'm wondering if a damper like this is really needed? or if it's just something 'nice to have' but otherwise it won't kill my HVAC early. I'm also wondering if it's required from whoever installed the HVAC system to include it as part of an HVAC system that's installed for a multi zoned (i.e. more than one thermostat) system?

Thanks in advance!

James

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  • Chris SeveneyBusiness Member
    Moderator
    Investor · VA · Member since 2015 · 21k+ posts · 19k+ votes
    3y

    @James Kim

    If your hvac system doesn’t have a variable speed drive and slow down at increased static pressure then yes a bypass damper should be installed otherwise you are stressing your system as it will be trying to send the amount of air for the system through one zone which will hurt your system and make it sound like a plane is taking off as well.

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  • Chris SeveneyBusiness Member
    Moderator
    Investor · VA · Member since 2015 · 21k+ posts · 19k+ votes
    3y

    @James Kim

    This is also hvac 101 for a home with one system and two floors/zones

    7e investments53 Reviews
  • James KimPro Member
    OP
    Investor · Los Angeles · Member since 2021 · 89 posts · 23 votes
    3y
    Quote from @Chris Seveney:

    @James Kim

    This is also hvac 101 for a home with one system and two floors/zones

     Thanks! Honestly I don't know much about HVAC and generally would just go with what I'm told but this home being new I decided I should ask. I'm assuming mine doesn't have a variable speed drive and slow down as the hvac techinican is strongly recommending I get a bypass damper. But wouldn't the builder who installed the HVAC be responsible for this? Or is it now up to me to "fix" this situation on my own dime? Being quoted $750 for the fix.

    Thanks again!

  • Chris SeveneyBusiness Member
    Moderator
    Investor · VA · Member since 2015 · 21k+ posts · 19k+ votes
    3y

    @James Kim

    $750 isn’t a bad price

    Yes I would have suspected the builder would have installed this.

    7e investments53 Reviews
  • James KimPro Member
    OP
    Investor · Los Angeles · Member since 2021 · 89 posts · 23 votes
    3y
    Quote from @Chris Seveney:

    @James Kim

    $750 isn’t a bad price

    Yes I would have suspected the builder would have installed this.

    @chrisSeveney , much appreciate your feedback. Thank you!
  • Austin, TX · Member since 2019 · 5k+ posts · 5k+ votes
    3y
    Quote from @James Kim:

    Hi,

    I'm not sure if this is the right section of the forum to post this question, but wanted to know if anyone has experienced this or have knowledge that they could share with me.

    My rental unit is a 2 floor house with separate thermostat on each floor with one HVAC unit. I recently had it serviced (annual) even though the house is a new build (2022). The technician told me that i needed a 'bypass damper' that connects from the return plenum to the supply plenum. I understand that this helps with controlling temperature and air pressure in zoned spaces and the technician also told me this helps prolong the life of the HVAC.  It also appears that a bypass damper is not something that might be 'required', though i may be wrong, and I'm asking the builder if this is something they could come back to install. I'm wondering if a damper like this is really needed? or if it's just something 'nice to have' but otherwise it won't kill my HVAC early. I'm also wondering if it's required from whoever installed the HVAC system to include it as part of an HVAC system that's installed for a multi zoned (i.e. more than one thermostat) system?

    Thanks in advance!

    James


     If it were mine, I'd get another opinion from another HVAC place (maybe 2 more) and see if it's just sales talk, or is actually needed.

    Just my 2 cents.

  • James KimPro Member
    OP
    Investor · Los Angeles · Member since 2021 · 89 posts · 23 votes
    3y

    @Scott Mac @Chris Seveney thanks for your tips. After speaking to the builder they were nice enough to come and install the dampers!

    James 

  • Chris SeveneyBusiness Member
    Moderator
    Investor · VA · Member since 2015 · 21k+ posts · 19k+ votes
    3y

    @James Kim

    That’s sign of a good builder. Like they say never hurts to ask.

    7e investments53 Reviews
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