Author Topic: off-gass  (Read 2525 times)

Offline oldguy2

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« on: January 11, 2012, 09:24:37 AM »
hi gang happy 2012 to everyone. recently watched an episode of holmes on homes and he called in the hvac guys to move an ac  which he claims was to close to furnace vents because of off gassing.. it needed to be 3ft from vents. now in my 27 yrs in hvac ive seen alot of things and an ac unit right next to furnace vents ive seen plenty. anyone care to chime on this one. i know holmes isnt the gospel and when he talks hvac i damn near want to strangle him.

Offline Admin

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Re: off-gass
« Reply #1 on: January 11, 2012, 11:31:12 AM »
Happy New Year.  I'm sitting in Punta Cana pool side right now, reading and drinking Mai-Tais!  A good start to 2012.

I've seen the holmes hvac guy make clearance mistakes on the show.  The hvac pro was maintaing 3' from the furnace vent to a dryer vent, when he should be maintaining 3' from the dryer vent to the furnace intake.  A dryer vent is not a building opening and can be beside a furnace vent.  He left a code violation as per Clause 7.5.2, by leaving the furnace intake within 3' of the dryer vent.

I normally try to keep vents from blowing on outdoor a/c units as they tend to corode the contactor and components inside, however there is no code that prevents an appliance vent from being installed near an a/c. Only a meter regulator vent needs 3' from a source of ignition, which is considered to be any part of the a/c.  To avoid hassles from the ESA I would ensure there is 3'3" in this case, even though our gas code trumps the electrical code.

I've heard of off-gassing for automotive air conditioning, and all manufacturers state to open windows for the first few minutes.  Apperently the plastics in the car can off gas benzene, which is linked to causing leukemia.  This is only a risk in cars newer than 6 months, and opening the window can subject you to the benzene created by car exhauts during traffic ect...  Even with the windows up and a/c on you could be pulling air from outside.  Alot of misinformation on this subject and I don't know how this pertains to a house a/c.

If there were an issue, there would be a Code to prevent it, IMO.