Make-up Air - Please explain what I need to tell my contractors

stacylhFebruary 18, 2013

(Cross posting this with HVAC forum)

Hello,

First of all, let me apologize if this is an issue that has been talked to death, but I am just now learning about this and my HVAC guy, contractor, and even appliance salesman are ignorant on this topic. Our area is usually behind on things.....

Anyway, we are doing a home reno that includes replacing ALL windows and doors with HE ones and we are doing a kitchen gut and replacement.

In doing so, we purchased a 36" gas rangetop and need to choose our ventilation for this. We are leaning toward a Vent-a-hood liner (hood will be made of cabinetry) that is rated 600 cfm (with 900 cfm effective, according to appliance salesman). After doing research on this, I found the topic of make-up air, which I'd never heard of before.

I consulted my contractor, HVAC guy and appliance guy and they all had very limited knowledge of this, so, basically, I need the low-down on what to tell this so they can plan/construct appropriately.

So, if you you know you're doing, please advise on the following:

1) Parts and ducting needed for Vent-a-hood system
2) Parts and ducting needed for a make-up air
3) How are range venting and make-up air linked together so the damper is opened when vent is turned on?
4) Sizing and spacing on all the above.

Our kitchen has easy access attic space above it (for the time being until drywall is replaced so I've got to hurry on this!)

Other considerations:

*2 gas furnaces (one located in basement and the other located in a crawlspace under a lower level addition
*Replacing current electric water heater to an on-demand one
*Gas fireplace (ventless)

Thanks so much!

Thank you for reporting this comment. Undo
worthy

See Martin Holladay's article.

If you don't get makeup air from a dedicated intake, it will be drawn through all the air leaks in your home and possibly even backdrafting CO from the furnace and water heater if these are not closed units.

Though I know you're looking for a cheap answer, I'd suggest finding a more educated HVAC designer with commercial experience to be safe.

However, if you don't run the exhaust all out all the time there may be no need for makeup air. We had a 700 cfm unit that was only run full throttle when my spouse cooked fish and offal. I just cracked open a patio door and all was OK.

    Bookmark   February 18, 2013 at 1:57PM
Thank you for reporting this comment. Undo
stacylh

Cracking the door or window is my husband's solution :)

However, we cook fish a lot since fishing is his favorite hobby. It just surprised me when the reputable appliance dealership where we purchased our appliances said they knew about the need for make-up air but had never sold a single make-up unit.

Thanks!

    Bookmark   February 18, 2013 at 5:37PM
Thank you for reporting this comment. Undo
virgilcarter

You need a more knowledgable and experienced HVAC person. Here's a useful reference article: http://www.greenbuildingadvisor.com/blogs/dept/musings/makeup-air-range-hoods

Good luck!

    Bookmark   February 18, 2013 at 7:00PM
Thank you for reporting this comment. Undo
SparklingWater

Just posted to your cross post on appliance stacy.

    Bookmark   February 18, 2013 at 8:54PM
Thank you for reporting this comment. Undo
stacylh

Thanks!

    Bookmark   February 19, 2013 at 8:53AM
Thank you for reporting this comment. Undo
energy_rater_la

ashrae 62.2

    Bookmark   February 19, 2013 at 3:24PM
Sign Up to comment
More Discussions
The movers are scheduled, now what to do?
We called our movers and they will be here on the 16th....
aimless07
Need help with 8' porch drop-off
I'm needing ideas for terracing steps from my front...
Beth LaPenna
Sending my floor plan modifications to the architect. Ideas?
I have to have all my structural changes decided by...
houserookie
Would love some feedback on the schematic design of our home
My wife and I are first time builders and would love...
Shane Sherman
What are you doing for your security system?
I know that's an extra cost, but I was curious as to...
aimless07
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™