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 10-14-2009, 02:28 PM   #1
Newbie
 
Join Date: Oct 2009
Posts: 13
Share |
Default

Does gas furnace need fresh air?


Hi,

We moved last year and the home has a 5 yr old gas furnace. Due to major renos when we moved I had the ducts cleaned. The cleaner noted that one of my air intakes was going straight outdoors, thus sucking fresh cold air (in winter) to supply the furnace with fresh air. He suggested I replace it with a passive intake : by means of an insulated tube coming from the outside and placing the other end next to the furnace.

I have 4 interior intakes. The flow was found to be sufficient with the 4 (it was measured by a pro).

Im wondering if I just cancel the exterior intake alltogether and add an interior one for a total of 5 - would this be sufficient or does the furnace need a passive intake for fresh air as suggested by the cleaner?

Franky123 is offline   Reply With Quote
Old 10-14-2009, 03:01 PM   #2
Member
 
Join Date: Sep 2008
Location: Upstate New York
Posts: 368
Default

Does gas furnace need fresh air?


Not sure you're speaking the right language here. Some high efficiency furnaces call for outdoor air for combustion usually with PVC. I have no idea what is mean by it being passive, or that you have 4 interior intakes.

Are we talking about ductwork returns perhaps? Pics might be in order for you to better explain this.

No offense to whoever cleaned your ductwork but a qualified HVAC pro is who you need to provide reliable information on how to handle your furnaces combustion air, if thats what we're talking about.


Last edited by dac122; 10-14-2009 at 03:03 PM.
dac122 is offline   Reply With Quote
Old 10-14-2009, 05:46 PM   #3
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,512
Default

Does gas furnace need fresh air?


Your Home may or may not need that fresh air intake.

Can't tell from here.

There should be at least a manual damper to control how much air it brings in. If not, have one installed. Or, better yet. Get the Aprilaire fresh air vent control that will allow it to be controlled automatically.
beenthere is online now   Reply With Quote
Old 10-14-2009, 06:00 PM   #4
Wire Chewer
 
Red Squirrel's Avatar
 
Join Date: Jun 2009
Location: Ontario, Canada
Posts: 3,200
Default

Does gas furnace need fresh air?


There is an exhaust for the CO produced by the furnace. The air that is exhausted out needs to be replaced or it would try to create a vacuum and I doubt the motor could, so the CO would have trouble escaping. So yes you do need two pipes, one for intake and one for exhaust. Normally they are black PVC, the same used for drain plumbing. (I think... I'm not an expert).
Red Squirrel is offline   Reply With Quote
Old 10-14-2009, 06:08 PM   #5
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,512
Default

Does gas furnace need fresh air?


Some areas don't allow ABS, others do.

What the OP has, is not an intake for combustion.
beenthere is online now   Reply With Quote
Old 10-14-2009, 06:27 PM   #6
Newbie
 
Join Date: Oct 2009
Posts: 10
Default

Does gas furnace need fresh air?


Beenthere are you familiar with a problem where the draft motor does not turn on, therefore the pilot does not light? When heat is comanded from t stat, nothing happens. I am at my sisters. I have the same furnace. Mine works like this. Heat comanded. Draft motor starts. Ignitor lights. Thermocoupler sees flame turns ignitor off. Burner lights. fan turns on. I can get draft motor to run by disconnecting one of the in line sensors with red wire connecting all. So I know that it does work. What is my next step. John

Last edited by simphead; 10-14-2009 at 06:31 PM. Reason: spelling
simphead is offline   Reply With Quote
Old 10-14-2009, 06:38 PM   #7
GC/Master Plumber/Mech
 
Join Date: Feb 2009
Location: Hays, KS
Posts: 1,467
Default

Does gas furnace need fresh air?


On the control board is there an LED flashing and if so count the number of flashes. There should be a code chart and post results
__________________
John Wayne once said "Life is tough and it is even tougher if you are stupid"

Tempstar and Trane Dealer
Plumber101 is offline   Reply With Quote
Old 10-14-2009, 06:54 PM   #8
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,512
Default

Does gas furnace need fresh air?


Could be blown fuse.
Bad wire from stat.
Bad stat.
Bad control board.
Bad inducer motor.
beenthere is online now   Reply With Quote
Old 10-14-2009, 06:55 PM   #9
GC/Master Plumber/Mech
 
Join Date: Feb 2009
Location: Hays, KS
Posts: 1,467
Default

Does gas furnace need fresh air?


Yuri,

He started a new thread
__________________
John Wayne once said "Life is tough and it is even tougher if you are stupid"

Tempstar and Trane Dealer
Plumber101 is offline   Reply With Quote
Old 10-14-2009, 07:31 PM   #10
30 year tech
 
hvac122's Avatar
 
Join Date: Dec 2007
Location: Lincoln, Nebraska
Posts: 427
Default

Does gas furnace need fresh air?


The pipe that is bringing in air sounds like fresh air for the house. Here it is code to have it and it is tied into the return air duct. It is different than combustion air which sounds like the other vents you have. The idea is that with houses being built tighter these days there needs to be some means of letting the house breath so it does not go into a negitive pressure.

Here our code doesn't let us put any damper of any sort in the pipe. I do agree with beenthere that it would be nice to control it somehow.

I would call your local codes department before you do anything and see what they have to say.

How old is the house?
hvac122 is online now   Reply With Quote
Old 10-14-2009, 08:27 PM   #11
Newbie
 
Join Date: Oct 2009
Posts: 13
Default

Does gas furnace need fresh air?


House if 45 yrs old.

By passive air I mean it is not motor aided or connected to the intake lines.

The pro who checked our air flow is a furnace tech, not the cleaner (2 separate inspections).

Passive air is an insulated 6" pipe which goes from exterior and the other end is placed near the furnace so that the flame can draw fresh air as needed.

I have been told this is code for our area so I think this is what we have to go with.

Thanks,
Frank
Franky123 is offline   Reply With Quote
Old 10-14-2009, 09:08 PM   #12
30 year tech
 
hvac122's Avatar
 
Join Date: Dec 2007
Location: Lincoln, Nebraska
Posts: 427
Default

Does gas furnace need fresh air?


That would be the combustion air for the furnace and is needed.
hvac122 is online now   Reply With Quote
Old 10-15-2009, 05:46 AM   #13
Newbie
 
Join Date: Oct 2009
Posts: 13
Default

Does gas furnace need fresh air?


Thanx hvac,

But should I just leave as aforementioned or does it have to be tied into a return vent? (sorry I kept saying intake - not correct term).

Thanx,
Frank
Franky123 is offline   Reply With Quote
Old 10-15-2009, 05:50 AM   #14
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,512
Default

Does gas furnace need fresh air?


Although some contractors will use that as a combustion intake.

It is not. Unless you have a supply vent in your furnace room.

It is a fresh air intake for your house, not a combustion intake for the furnace.

beenthere is online now   Reply With Quote
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
Lennox Furnace G27M Series Unreliable operation: pressure switch or else? sheppard1977 HVAC 7 01-14-2013 05:42 PM
Furnace air filtration advice stephen_smith HVAC 7 12-24-2010 02:24 AM
Make up ventilation through return on furnace question creamaster HVAC 8 09-27-2009 04:53 PM
Problems with new furnace..Overheating, having to reset. Furnace too big? Tommy2 HVAC 41 12-01-2008 01:55 PM
New Cased Coil - Install to Furnace - PICTURES!! hartkem HVAC 39 11-18-2008 01:45 AM




Top of Page | View New Posts

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