Heating, Air Conditioning, Fridge, HVAC/Venting outside - hvac


In a 2 pipe gas furnace that is vented out of the side of a house what is the minimum distance (and max) that the intake and outtake vents should be? What issues could happen if the distance is less than the minimum?


The distances are specified in the manufacturer's Installation Instructions. It's quite important to keep the two terminations in the same "pressure zone" to avoid nuisance shutdowns. In the event the two are too close, combustion products can be drawn into the combustion air.

This is "black and white" stuff: If your contractor has them too close, he has to correct it. The "AHJ" (Authority Having Jurisdiction") should fail the installation at inspection (you did insist on a permit and inspection, right?), and you are well within your rights to withhold final payment until corrections are made.


Heating, Air Conditioning, Fridge, HVAC

All Answers

Answers by Expert:

Ask Experts


Fred Weldin


I can't help you if your whatsis won't work, people (Especially if it's a refrigerator); I have no experience with appliances, and I haven't been involved with H&AC service and repair since March 08, 1996 (Thank the Lord); I always send a "standard" reply to appliance questions and H&AC "Service and Repair" questions (about 20 a month), so if you want to know why your whatsis isn't working like it used to, ask someone else. A lot of my answers arenít read by the questioners; in that event, I always send reminders to read the answers for a month or more (the word "idiots" comes to mind - actually there's another more appropriate word, but discretion prevents its use here). If you have questions about how big a unit you need, if one room's warmer than the others, if you want an opinion oas to scope of work on bids received, etc. just ask. Do visit www.askweldin.com, there's a lot of good information on sizing, ductwork, efficiency, as well as some techniques accomplished DIY-ers can use to troubleshoot and improve their H&AC. Finally, I want to thank all of the kind, serious people whom I meet here: I enjoy working with you. My wife says I'm "snarky" from time to time; as for you others, please use your imagination as to the responses swirling on the snarky side of my brain when I read your questions.


53 years in the business. See www.askweldin.com


B of ME U of D 1965, numerous classes, seminars and a lot of "Hands On" learning since.

©2017 About.com. All rights reserved.