Danny Pritchard Posted February 4, 2004 Report Share Posted February 4, 2004 Found this in a 1947 beach house today.That is a dryer vent behind the water heater with a damper.Can't figure out why the damper was installed.This is in a closet in the master bedroom which used to be the garage.I basically said get the water heater out of there and redo everything. Danny Pritchard Download Attachment: gas heater and dryer vent.jpg 61.73 KB Quote Link to comment Share on other sites More sharing options...
Chad Fabry Posted February 4, 2004 Report Share Posted February 4, 2004 The damper is for the energy conscious to divert the warm, moist air from the dryer into the home all winter. This person is so energy conscious that they even insulated the cold water pipe. Quote Link to comment Share on other sites More sharing options...
Brian G Posted February 4, 2004 Report Share Posted February 4, 2004 I think that vent pipe has to run straight up a little before turning, but I can't really remember. Damn, I asked that on the ASHI forum once, now I don't remember the answer...BRAIN CRAMP! [:-headache] Brian G. It'll Come to Me...Next Week [:-indifferent] Quote Link to comment Share on other sites More sharing options...
Terence McCann Posted February 5, 2004 Report Share Posted February 5, 2004 Hi Danny: Good call. Gas fired water heaters are prohibited in bedrooms, bathrooms, clothes closets etc... Regarding the flue, IRC code 2426.6.4 "bends, 45 degree max except one 60 degree". I would say from your pic that doesn't cut it either. Any shut off valve on the cold water line? Pardon me, pointless question - it's like trying to quantify how illegal is illegal. Last but not least, why on earth someone would want a nasty dryer vent discharging into their bedroom closet is beyond me. I hope that was installed before the remodel. Even still, I find those dryer vent bypasses offensive. Quote Link to comment Share on other sites More sharing options...
a46geo Posted February 5, 2004 Report Share Posted February 5, 2004 Originally posted by Brian G. I think that vent pipe has to run straight up a little before turning, but I can't really remember. Damn, I asked that on the ASHI forum once, now I don't remember the answer...BRAIN CRAMP! [:-headache] Brian G. It'll Come to Me...Next Week [:-indifferent] Dan, I don't know about elsewhere, but here (S.E. Michigan) you can elbow right off of the diverter. The pipe must maintain at LEAST a 1" rise for every foot of run. This one seems to slope down. But, I like the way you wrote it up. George Quote Link to comment Share on other sites More sharing options...
Danny Pritchard Posted February 5, 2004 Author Report Share Posted February 5, 2004 I failed to mention in my post; There was inadquate clearance to combustibles for the flue Inadquate slope for the flue No shutoff for the cold water The gas line was not bonded to the grounding system Plastic dryer vent T/P line not extended to the exterior Metal chips on the burner No make up air supplied to the closet for the water heater I'm just still curious why the damper was installed in the dryer exhaust. Danny Pritchard Quote Link to comment Share on other sites More sharing options...
a46geo Posted February 5, 2004 Report Share Posted February 5, 2004 Lets not confuse the issue. "Make up air" and "combustion air" are technically two separate issues. Combustion air is needed to burn fuel. Where a gas flame is the concern, primary air, (that which mixes with the fuel and is ignited) secondary air,(the atmosphere in which the burn takes place) and draft air are all part of combustion air. Back in the 70's Lennox taught a 28 to 1 ratio for natural gas. Now days you often see 30 to 1. Restrict this air and you could have a very serious problem. Cut it off entirely and you will have no flame. Make up air on the other hand is external (usually outside) air introduced to replace exhausted air to keep the exhausting process balanced. Like in a commercial kitchen, welding shop or indoor gun range. Make up air under many circumstances has to be "conditioned" (heated or cooled) before it is introduced into the space. An air to air heat exchanger is one example of a make up air system. The only reason I am bringing this up is that I have seen several instances on HI forums where the terms were interchanged. They are not interchangable. In todays litigious society, and to keep form un-impressing a client that happens to know the difference, I thought some would like to know. Please, no offense meant. George Quote Link to comment Share on other sites More sharing options...
Terence McCann Posted February 5, 2004 Report Share Posted February 5, 2004 Originally posted by a46geo Lets not confuse the issue. "Make up air" and "combustion air" are technically two separate issues. Combustion air is needed to burn fuel. Where a gas flame is the concern, primary air, (that which mixes with the fuel and is ignited) secondary air,(the atmosphere in which the burn takes place) and draft air are all part of combustion air. Back in the 70's Lennox taught a 28 to 1 ratio for natural gas. Now days you often see 30 to 1. Restrict this air and you could have a very serious problem. Cut it off entirely and you will have no flame. Make up air on the other hand is external (usually outside) air introduced to replace exhausted air to keep the exhausting process balanced. Like in a commercial kitchen, welding shop or indoor gun range. Make up air under many circumstances has to be "conditioned" (heated or cooled) before it is introduced into the space. An air to air heat exchanger is one example of a make up air system. The only reason I am bringing this up is that I have seen several instances on HI forums where the terms were interchanged. They are not interchangable. In todays litigious society, and to keep form un-impressing a client that happens to know the difference, I thought some would like to know. Please, no offense meant. George Nice explanation George! If I might add, a lack of make up air is directly proportional to a lack of combustion air. In our condo, for example, the hot water heater, dryer and furnace is in the same little room. There are two, 6" round ducts, placed high and low, in this room. These are really needed to supply the necessary makeup air/replacement air for combustion/dryer venting. To tell the truth though I've never broken out the slide rule to see if the free area was sufficient enough to take care of the needs with the utility room door closed. I took the easy path, just left the door open. Quote Link to comment Share on other sites More sharing options...
Danny Pritchard Posted February 6, 2004 Author Report Share Posted February 6, 2004 George, Good explanation and no offense taken.I tend to intermingle the terms.What I was referring to is what Terry said about the ducts bringing in fresh air from the exterior. Danny Pritchard Quote Link to comment Share on other sites More sharing options...
n/a27 Posted February 6, 2004 Report Share Posted February 6, 2004 What's a slide rule?? Quote Link to comment Share on other sites More sharing options...
Renron Posted March 11, 2004 Report Share Posted March 11, 2004 Anyone else notice that if the dryer vent/damper blows across that area it could pull the burt gas fumes away from the draft hood by way of venturi/drafting action and into the living space? Ron Quote Link to comment Share on other sites More sharing options...
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