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

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-30-2012, 01:33 PM   #1
Newbie
 
Join Date: Jan 2012
Posts: 3
Share |
Default

Fresh Air Intake Vent & Cold Weather


Hi all, I live in central Manitoba in a newly constructed house. The cold air intake vent is insulated and connected into the return air(plenum) of an *electric* furnace(for fresh air).

I'm trying to get around a problem with condensation during cold weather(-20 and under). Whats happening is that I'm getting condensation at the end of the vent, where it meets the furnace venting(within the plenum).

Any solutions other then installing an HRV? I was thinking there could be a way to trap the condensation and funnel it out to a pipe in the drain?

In theory the fresh air vent could be closed up, but I'm worried about the central exhaust in the house(it's a tight house).

Hopefully my description makes sence, thanks kindly

hvacamigo is offline   Reply With Quote
Old 01-30-2012, 03:53 PM   #2
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 25,027
Default

Fresh Air Intake Vent & Cold Weather


Other then using an automatic damper, no way around it.

beenthere is online now   Reply With Quote
Old 01-30-2012, 03:56 PM   #3
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 9,394
Default

Fresh Air Intake Vent & Cold Weather


Try insulate the metal where it attaches with foil back insulation and silver metal duct tape from HDepot. You can buy one of those water heater insulation blankets and cut pieces from it or look for that insulation. Hard to come by as it is used by commercial sheet metal shops and they may not want to sell you a small piece.
__________________
"Cut it twice and it is still too short".
yuri is offline   Reply With Quote
Old 01-30-2012, 04:39 PM   #4
Newbie
 
Join Date: Jan 2012
Posts: 3
Default

Fresh Air Intake Vent & Cold Weather


Quote:
Originally Posted by yuri View Post
Try insulate the metal where it attaches with foil back insulation and silver metal duct tape from HDepot. You can buy one of those water heater insulation blankets and cut pieces from it or look for that insulation. Hard to come by as it is used by commercial sheet metal shops and they may not want to sell you a small piece.
Thanks but I think the cold air will still condense within the plenum...(just not drip outside)
hvacamigo is offline   Reply With Quote
Old 01-30-2012, 05:09 PM   #5
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 9,394
Default

Fresh Air Intake Vent & Cold Weather


not necessarily, do U run your furnace fan continuos for circulation/fresh air/moisture control? if it is running then the cold air will mix with the return air and the mix will be warm enough to not sweat the duct. I live in Winnipeg and know all about that issue. If you want to talk about an HRV that is a MUCH better NRG efficient solution.
__________________
"Cut it twice and it is still too short".
yuri is offline   Reply With Quote
Old 01-30-2012, 05:30 PM   #6
how
Member
 
Join Date: Feb 2011
Location: Vancouver BC
Posts: 1,491
Default

Fresh Air Intake Vent & Cold Weather


I never have to deal with electric furnaces so this could be ignorance speaking but what about using a passive fresh air supply instead of one connected to your return air plenum. In atmospheric gas furnaces you'd just go up one pipe size ( from the size recommended for a direct return air connection) and bring it in to within 18" of the burners. In cold climates it would often terminate in a bucket that would act as a spill trap.


Being electrically fired (CO free) I don't know in your system if the plenum hole could just be left open with a grill covering and with the passive system terminating below?
I'm sure folks here with more than just a pondering knowledge could speak to this.

Last edited by how; 01-30-2012 at 05:32 PM.
how is offline   Reply With Quote
Old 01-30-2012, 05:40 PM   #7
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 9,394
Default

Fresh Air Intake Vent & Cold Weather


Not so good as it will suck air from the basement and not out of the rooms where we really want it sucked. Even with a bucket or loop you get -20 to -40C air migrating in and a nasty cold area. The only passive suction setups I used to see where for the supply from an hrv to near the RA duct. nowadays we hook it up to the duct.
__________________
"Cut it twice and it is still too short".

Last edited by yuri; 01-30-2012 at 05:45 PM.
yuri is offline   Reply With Quote
Old 01-31-2012, 08:33 AM   #8
Newbie
 
Join Date: Jan 2012
Posts: 3
Default

Fresh Air Intake Vent & Cold Weather


Thanks for all your replies.

Im trying to save some money but I dont think I have much choice, I'll probably end up getting an HRV or air exchanger. Yuri, if you have a recommendation for our climate I'm all ears (house is 2600 sf, prob 120 cfm?)
hvacamigo is offline   Reply With Quote
Old 01-31-2012, 08:43 AM   #9
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 9,394
Default

Fresh Air Intake Vent & Cold Weather


Lifebreath 155 Max or the Lennox Healthy Climate 150 which is made by Lifebreath for them. I ripped out that central exhaust fan in my house and put a Lifebreath in place of it. Is it 1300 sf ft per level? I don't count the basement in sq.footage. My 1400 sq ft bungalow uses a 155 Max but you may need a 200 if your house is bigger.

__________________
"Cut it twice and it is still too short".

Last edited by yuri; 01-31-2012 at 08:54 AM.
yuri is offline   Reply With Quote
The Following User Says Thank You to yuri For This Useful Post:
hvacamigo (01-31-2012)
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Ice build up in Fresh Air Intake Werner Site Feedback and Suggestions 0 12-04-2011 09:28 PM
bathroom vent leaking cold air BlueBSH HVAC 0 12-01-2011 10:37 AM
Great stuff or equivalent product for cold weather? Red Squirrel Building & Construction 11 01-21-2011 10:19 AM
proper intake vents for ridge vent?? arty007 Roofing/Siding 14 07-31-2010 12:28 PM
Running network wiring in a cold air return vent? mcvane Electrical 26 04-19-2007 07:52 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.