Forums | Home Repair | Home Improvement | Painting | Interior Decorating | Remodeling | Landscaping


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 12-29-2008, 02:31 PM   #1
Newbie
 
Join Date: Dec 2008
Posts: 6
Share |
Default

Combustion (make-up) air in basement


Hello,
I am about to start remodeling my basement and have a few questions regarding allowances for combustion air. The house is about 13 years old in the Chicago suburbs. According to all my calculations, I will need 6,400 cu ft. for combustion air. Becasue the mechanical room containing my furn. & w/h is not large enough, I intended on using louver doors to tie in air from the rec room. Even in this situation, I will be 400 cu ft short due to the planned ceilings in the rec room. I will be short regardless of if I use a suspended ceiling or dry wall. The way I look at it, I have two options. 1) leave the ceiling unfinished and paint the entire ceiling or 2) install an outside combustion air kit to my mechanical room.

I was hoping somebody would be able to give me some advice/opinions on my situation. Also, if I decide to install the outside kit, is there any information you could pass along as to how to do it, where to find one? I have only been able to find very limited information and no complete kits or instructions. Any web links in installation instructions would be greatly appreciated.
Thank you in advance.
tthacke is offline   Reply With Quote
Old 12-29-2008, 03:19 PM   #2
Member
 
Join Date: Dec 2008
Location: West Michigan
Posts: 440
Default

Combustion (make-up) air in basement


Seems like a lot of combustion air. From what I have seen, typically a 6 inch or 8 inch round duct piped to the outside is the norm for residential mechanical rooms.
SKIP4661 is offline   Reply With Quote
Old 12-29-2008, 05:12 PM   #3
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 8,329
Default

Combustion (make-up) air in basement


How many BTU's are the water heater and furnace rated for. Generally we use 1 sq ft/100,000 Btus.
yuri is online now   Reply With Quote
Old 12-29-2008, 05:34 PM   #4
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Default

Combustion (make-up) air in basement


I am reading the specs for bringing in some outside air to supplement the your slight deficit.
A 4" round is good for up to 40k btu. A factory made make up air would cost more than 4 lengths of 4" pipe and an outdoor dryer-style fresh air intake.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 12-29-2008, 05:57 PM   #5
Member
 
tk03's Avatar
 
Join Date: Sep 2008
Location: PA
Posts: 167
Default

Combustion (make-up) air in basement


See the following link to amount of combustion air required by national code. Your local code may require more.
The only required make up air needed is the difference of what is needed minus what you have. Is the basement area to to upstairs an open doorway or does the doorway have a door at the top of the stairs.
http://www.comfort-calc.net/Combusti...lculation.html
There are a few ways to get what is required.
I can supply options once you answer the above questions.
tk03 is offline   Reply With Quote
Old 12-29-2008, 08:35 PM   #6
Newbie
 
Join Date: Dec 2008
Posts: 6
Default

Combustion (make-up) air in basement


Thank you all for your help. Below are answers to the questions asked.

The furnace is 88,000 btu and the water heater is 40,000 btu...for a total of 128,000 btu. 128,000 / 20 = 6,400 cu. ft. required for the combustion air. While I will have a door to the mechanical room/crawl space, it will be a louver-type to draw in air from the rest of the basement (i.e. the rec room). After putting a ceiling on the rec room only, my total air volume is 6,020 cu. ft.

Regarding the stairway, I will have a door at the top that will need to be closed.

I hope this better helps to lay out the situation. Thank you all again.
tthacke is offline   Reply With Quote
Old 12-29-2008, 09:43 PM   #7
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Default

Combustion (make-up) air in basement


If you want to provide fresh air for all your combustion needs instead of just running the right sized pipe to make up the difference your free space is lacking you will need a six inch pipe.


[IMG]file:///C:/DOCUME%7E1/John/LOCALS%7E1/Temp/moz-screenshot-11.jpg[/IMG]
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 12-30-2008, 07:06 AM   #8
Newbie
 
Join Date: Dec 2008
Posts: 6
Default

Combustion (make-up) air in basement


Thanks hvaclover. If I run that pipe/hood (similar to the picture you included) into the basement, do I need to put an extension of flex on it to run it to the ground, or can I just leave the 6" pipe sticking out of the wall?
tthacke is offline   Reply With Quote
Old 12-30-2008, 10:46 AM   #9
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Default

Combustion (make-up) air in basement


First off buy afresh intake that has a screen in it goes outside. You then terminate the six inch pipe twelve inches above the floor. Use hard pipes made of 26ga steel.

Also add insulation to the pipe drop avoid sweating.

The kit I showed you would cost about$200.

But it connects to the cold air return. The hood vent and six pipe is a much better option.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 12-30-2008, 11:00 AM   #10
Newbie
 
Join Date: Dec 2008
Posts: 6
Default

Combustion (make-up) air in basement


I understand. Thank you. Should the end of the pipe be terminated into a disfuser or anything? I've read about running them into a 5 Gal bucket.

I have about 12' from my outside wall to the furnace. Can the pipe drop along side the wall, or does it need to be taken closer or a horiz. path to the furnace before it drops?

I apologize for all the questions, I just want to make sure I have all the information.
tthacke is offline   Reply With Quote
Old 12-30-2008, 12:07 PM   #11
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Default

Combustion (make-up) air in basement


Quote:
Originally Posted by tthacke View Post
I understand. Thank you. Should the end of the pipe be terminated into a disfuser or anything? I've read about running them into a 5 Gal bucket.

I have about 12' from my outside wall to the furnace. Can the pipe drop along side the wall, or does it need to be taken closer or a horiz. path to the furnace before it drops?

I apologize for all the questions, I just want to make sure I have all the information.
No what you describe is fine and more than close enough
I just strap them to the wall and leave the bottom open with no other fitting.

I would suggest maybe chicken wire just in case. A five gallon bucket would create it's own pressure zone, unless I miss my guess. That would impede the full air flow.

I could see a five gallon bucket with several one inch holes drilled around the bucket from bottom to top.














[IMG]file:///C:/DOCUME%7E1/John/LOCALS%7E1/Temp/moz-screenshot-14.jpg[/IMG]
__________________
Just slow, not stupid.

Last edited by hvaclover; 12-30-2008 at 01:01 PM.
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
Spray foam insulating joists in basement? peethree Building & Construction 13 11-28-2010 08:54 AM
Mysterious Basement Leak MidTenn General DIY Discussions 4 08-31-2008 02:20 PM
Basement Moisture problem jimdd Remodeling 1 07-22-2008 02:48 PM
Finished Basement Quandry SonOfPirate Remodeling 5 04-29-2008 04:23 PM
Sub Basement Walkout - Please Help pgs_28 Building & Construction 11 08-12-2007 09:55 PM




Top of Page | View New Posts

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