Fresh air intake requirements for a gas water heater?

What would be the fresh air intake requirements for a 36,000 BTU natural gas water heater?

I used to have a 72,000 BTU 80% natural gas furnace, and a 36,000 BTU natural gas water heater. The fresh air intake for both was provided by a vent (i.e. hole) in my basement wall in the furnace room to the outside.

I've since upgraded my furnace to a 93% efficiency model, so its fresh air intake is supplied by a PVC pipe that runs outside through the concrete foundation (through a new hole).

So I'm wondering (hoping) whether I can make the original vent smaller, as it now only serves the water heater, and all the cold air coming in from the outside is wasting energy needlessly.

The furnace installer (who was pretty junior as he was young and screwed a couple of things up and I had to call the company back to fix the problems with an older repair man) had said to leave the original vent alone. But I would think that the water heater (36,000 BTU) could suffice with a smaller fresh air intake vent than what was originally done to serve both the water heater and the furnace? Assuming the vent size is related to the BTU capacity, the gas water heater represents

1/3 of the original setup (36,000+72,000).
Reply to
jonny_rizzo
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I lived in three houses with gas water heaters. They had no vents at all. I see no reason it could not be reduced a bit.

Reply to
Edwin Pawlowski

Not knowing the exact situation, you need 1 sq inch per 10k btu of fresh air, one air inlet high and one low. Respond directly to me and I can send you the ~4 meg pdf file. That I have or you can use google like I did

Reply to
SQLit

The installation manual for the heater should have pretty clear specs on air intake. These things are calculated by the manufacturer, just so the installer or homeowner doesn't have to "guess". Not that it stops them from guessing anyway :-)

Reply to
Andrew Duane

Check with your city or call your local energy company. In my city fresh air intakes are only required for gas furnaces. Frankly, it's not a bad idea at all to have one for the other gas appliances anyway, to reduce the risk of backdrafts, but you're best off finding out what is code in your area.

HellT

Reply to
Hell Toupee

I dought you need an intake, it just cools the house, close it and check for no flue draw, houses leak alot of air. Get a blower door test to confirm it.

Reply to
m Ransley

If the water heater is in the durnace room and the furnace room is closed off from the rest of the basement ; the fresh air inlet may still be required, depending on the size of the furnace room. You can probably reduce it in size. I don't have my code books with me, but SQLit may have all you need. Have him email it to you.

Stretch

Reply to
Stretch

Thank you all for the replies. I'll call the energy company to confirm whether it is needed or not (my hot water tank is a rental). Last night I spoke to a few friends and family members living in relatively new houses, and none of them had a vent specifically for their hot water tanks, so it may not be needed at all.

Reply to
jonny_rizzo

Of all the houses we have owned or rented in six states we have never had a separate air intake for our gas water heaters. Typically, the heater is in the garage. Sometimes it is inside the house, like where we live now. The heater just draws its air from the house or garage. I suppose if it was in a closet with a sealed door, you might need a vent.

Reply to
Dick

You're sure not current on code.

(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) snipped-for-privacy@7cox.net

Reply to
DanG

What code would that be?

Reply to
Bob

Uniform plumbing code. Table 5-1

(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) snipped-for-privacy@7cox.net

Reply to
DanG

Reply to
Dick

replying to SQLit, Kara Walton wrote: Could you please send me the PDF file you have. I am sealing my hot water tank closet and want to make sure my high low inlets are correct.

Reply to
Kara Walton

That post was made over 10 years ago. You think the poster is still there, at the keyboard, waiting to respond to your request?

Reply to
trader_4

he is if he is one of the Obummer supporters who are still blaming everything on Bush.

Reply to
Taxed and Spent

replying to Taxed and Spent, follybud wrote: yep ... dems tax & spend and publicans borrow and spend ... both hurt but only one requires you check your brains at the door ...

Reply to
follybud

replying to SQLit, Beaul Haynes wrote: please send files

Reply to
Beaul Haynes

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