HRV Duct Sizing Question With Damper - HVAC - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC


Thread Tools Display Modes
Old 04-19-2013, 03:30 PM   #1
Join Date: Oct 2008
Location: Albany, NY
Posts: 76
Rewards Points: 83

HRV Duct Sizing Question with Damper

I'm trying to design an HRV ducting system and I had a few theoretical questions in regard to using a damper.

I'd like to have two main trunks that come off the HRV: trunk A and trunk B. These two trunks will be pulling the air OUT of the rooms.

Trunk A will serve a kitchen and two bathrooms.
Trunk B will two crawlspaces.

If I place a normally open damper on trunk B, and I energize the damper, the damper will close.

My expectation is that the CFM amount will fall to zero in Trunk B and will increase in Trunk A.

Should I size the Trunk A and the Trunk A branches to accomodate the CFM when the Trunk B damper is closed, or when it is open?


toddmanqa is offline   Reply With Quote
Old 04-20-2013, 04:21 AM   #2
An old Tradesmen
Join Date: Oct 2008
Location: Somewhere
Posts: 29,990
Rewards Points: 11,452

HRV Duct Sizing Question with Damper


Trunk A should be sized to 125% of the air you want to go through it when ever the HRV is running.


When posting in certain forums, knowing your location will help others give better feedback/advice/solutions to your questions.
beenthere is online now   Reply With Quote

cfm , damper , duct , hrv , size

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Duct work sizing for 800 CFM unit mattorrell HVAC 11 03-25-2013 03:01 PM
Bathroom Exhaust Fan Duct Sizing Lyndon HVAC 6 02-06-2012 08:35 AM
Old flex duct question doityourselfer2 HVAC 3 12-05-2011 01:37 PM
Question Re: New Furnace and Duct Sizing DSimo HVAC 3 06-17-2008 08:24 AM
Duct sizing question Rob HVAC 1 06-04-2005 01:42 PM

Top of Page | View New Posts