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 10-20-2008, 09:07 PM   #1
Newbie
 
Join Date: Oct 2008
Posts: 4
Rewards Points: 10
Default

Venting high eff. gas furnace through the wall.


I am installing a 95% gas furnace. Wondering if I can run exhaust out one side of house and intake through the other. As I understand the combustion air may be terminated under a deck, but vent may not. That is my delima. They would be sloped 1/4" / ft and be basically the same hgt as far as atmospheric pressure goes. Can anyone help? Thanks.

Prince1 is offline   Reply With Quote
Old 10-21-2008, 08:26 AM   #2
Newbie
 
Join Date: Oct 2008
Posts: 4
Rewards Points: 10
Default

Venting high eff. gas furnace through the wall.


The only reason I ask this is because all the diagrams I have looked at seem to show a min of 3" apart and max of 24" apart. I guess I don't understand that and wondering if anyone knew more about it. Thanks.

Prince1 is offline   Reply With Quote
Old 10-21-2008, 11:37 AM   #3
Member
 
Join Date: Sep 2008
Location: Portland, OR
Posts: 1,186
Rewards Points: 500
Default

Venting high eff. gas furnace through the wall.


Yes you can do that. I have done that in really tight places. One had to have the vent go up a chimney that was real tight.

You can even terminate the intake inside the house but I don't recommend that although I have seen it done.
__________________
My idea of a perfect day: No where to go and all day to get there.
Marvin Gardens is offline   Reply With Quote
Old 10-21-2008, 04:00 PM   #4
30 year tech
 
hvac122's Avatar
 
Join Date: Dec 2007
Location: Lincoln, Nebraska
Posts: 427
Rewards Points: 250
Default

Venting high eff. gas furnace through the wall.


The reason that the manufactures don't want them on different sides of the house is because of the pressure differences that will occur and may cause intermintent unit lockouts. I would highly suggest you follow the manufactures installation manual on this.
hvac122 is offline   Reply With Quote
Old 10-21-2008, 06:31 PM   #5
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

Venting high eff. gas furnace through the wall.


Not a good idea for the following reasons:

The pressure zones are are completely different from side of the home to the other because of air press differences and air currents.

All current production 95% have a two port pressure switch that sense this diff in the vent and combustion air pipes and would cause the the press switch to lock out the furnace burners.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 10-21-2008, 06:45 PM   #6
Member
 
Join Date: Sep 2008
Location: Portland, OR
Posts: 1,186
Rewards Points: 500
Default

Venting high eff. gas furnace through the wall.


I just installed an Armstrong 95% and they state that you can vent in different places. They say that the intake can be inside and the exhaust outside.

Now that is a pressure difference. Not a big one but there is a difference in pressure especially when the wind is blowing.

I was going to do an inside intake but the energytrust.org says to get their rebate of $200 I have to have the intake outside.

The one I vented up a chimney and did the intake out the back is working fine.

Where the pressure switch comes into play is if the pressure in the exhaust gets too high, then it will shut down. This assumes that the vent is blocked. In fact to test them I just put my hand over the exhaust and it shuts down.
__________________
My idea of a perfect day: No where to go and all day to get there.
Marvin Gardens is offline   Reply With Quote
Old 10-21-2008, 07:35 PM   #7
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

Venting high eff. gas furnace through the wall.


Quote:
Originally Posted by Marvin Gardens View Post
I just installed an Armstrong 95% and they state that you can vent in different places. They say that the intake can be inside and the exhaust outside.

Now that is a pressure difference. Not a big one but there is a difference in pressure especially when the wind is blowing.

I was going to do an inside intake but the energytrust.org says to get their rebate of $200 I have to have the intake outside.

The one I vented up a chimney and did the intake out the back is working fine.

Where the pressure switch comes into play is if the pressure in the exhaust gets too high, then it will shut down. This assumes that the vent is blocked. In fact to test them I just put my hand over the exhaust and it shuts down.
They are rated for indoor air, yes. But not for going into diff press zones.


The press differential is measured by the double tap press switch and will cut out if not with in a specific range of WC".
I had a go round with my OLD,old school dist. He told everybody they could run pipes to diff side of home.
I called Allied air tech service and they said "NO WAY JOSE'" direct quote, that. So they gotta go out on the same side.

Don't take my word for it, call Armstrong .
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 10-21-2008, 09:12 PM   #8
Newbie
 
Join Date: Oct 2008
Posts: 4
Rewards Points: 10
Default

Venting high eff. gas furnace through the wall.


I appreciate all the info....keep it coming if anyone has more thoughts. I had a contractor give an estimate and he thought it would be fine if they were to do the install. Thanks again.
Prince1 is offline   Reply With Quote
Old 10-21-2008, 09:13 PM   #9
Newbie
 
Join Date: Oct 2008
Posts: 4
Rewards Points: 10
Default

Venting high eff. gas furnace through the wall.


MAybe I can run them both out the back, but I am getting near a dv gas fireplace. Ugh.
Prince1 is offline   Reply With Quote
Old 10-21-2008, 09:30 PM   #10
Member
 
tk03's Avatar
 
Join Date: Sep 2008
Location: PA
Posts: 167
Rewards Points: 150
Default

Venting high eff. gas furnace through the wall.


READ....That will tell you. The I&O will address the venting issues. They tell you what you can do not what you can't do. I they don't show it in pictures and do not talk about it in text best bet is do it.
Two different walls is going to be a problem if they use a suction/pressure switch as opposed to a pressure switch. Two different walls and a suction/pressure switch will give you shut downs.
You stated the vent and air intake need to be no more then 24" apart. How much easier is it to understand. Not to sound coy but it does not matter if we undersatnd it or not, it is what they decided to pay for in the certification process.
tk03 is offline   Reply With Quote
Old 10-21-2008, 11:20 PM   #11
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,023
Rewards Points: 3,712
Default

Venting high eff. gas furnace through the wall.


For every install that works fine with the intake and vent on opposite sides of teh house. There are 100 that don't.
beenthere is online now   Reply With Quote
Old 10-21-2008, 11:36 PM   #12
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

Venting high eff. gas furnace through the wall.


Quote:
Originally Posted by beenthere View Post
For every install that works fine with the intake and vent on opposite sides of teh house. There are 100 that don't.

C'Mon! Give more detail. You're sand baggin' us.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 10-21-2008, 11:43 PM   #13
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,023
Rewards Points: 3,712
Default

Venting high eff. gas furnace through the wall.


LOL...

If I can't get both to the same wall. I use indoor air for combustion. It works better.

I hate cutting PVC at 1 in the morning to get the heat going again.
beenthere is online now   Reply With Quote
Old 10-21-2008, 11:48 PM   #14
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

Venting high eff. gas furnace through the wall.


Quote:
Originally Posted by beenthere View Post
LOL...

If I can't get both to the same wall. I use indoor air for combustion. It works better.

I hate cutting PVC at 1 in the morning to get the heat going again.
If it's 1 in the morning no sane customer would have me in house, heat or not...I get cranky after 12am.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 10-21-2008, 11:51 PM   #15
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

Venting high eff. gas furnace through the wall.


Quote:
Originally Posted by hvaclover View Post
If it's 1 in the morning no sane customer would have me in house, heat or not...I get cranky after 12am.

By the way...how come none us "Pros" brought up a concentric termination? That only needs a half brick.

__________________
Just slow, not stupid.
hvaclover is offline   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
Removal of interior wall Bobb G Remodeling 4 09-15-2008 02:30 PM
Raising Doorway Height (load bearing?) treefrog Building & Construction 6 02-25-2008 10:11 PM
furnace venting redman HVAC 2 01-21-2008 09:28 PM
Wall furnace blowing out kwoodsong General DIY Discussions 5 12-09-2007 07:14 PM
Framing a 16 foot high wall for shop pranderson Building & Construction 10 01-01-2006 05:23 PM




Top of Page | View New Posts

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