Wall built next to Water Heater and Furnace area

Old 12-27-01, 05:40 AM
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Question Wall built next to Water Heater and Furnace area

In process of framing the basement for remodeling. Does anyone know what the code dictates for the amount of space required between the Furnace (GAS) and Water Heater (Gas).

Also, obviously ventilation will be crucial when surrounding these appliances. Do louvered doors work best or is a large slider sufficient to provide amount of air flow needed when framing this area.?

Any help would be appreciated.

Happy Holidays.


Old 12-27-01, 06:00 AM
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No expert here. If I was you, I would look at the furnace and water heater, there are usually labels which detail clearance requirements and ventilation too.
Since each State/City has its own codes, you may want to check with the local building inspectors office.
I am in California and have work on houses which had the furnace and water heater in the same closet with approximately 6-8" between them. The doors had louvered panels, vent panels (like on heater/AC vents) and even peg board panels. I have heard that the peg board panels are not the best, they restrict to much air flow. So they either have to be bigger in size or they won't work right.
Old 12-28-01, 01:35 AM
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(Note: I am not an HVAC expert, but I have researched the same questions and here's what I found)

(1) Clearances - you will find this information in the owner's manuals for the furnace and the water heater. It may possibly also be on the labels as well.

(2) Ventilation - This is more difficult.

Long answer: First you must determine if your partitioning will place your furnace and water heater in "confined space". A confined space is defined as less that 50 cu. ft. of volume per 1000 BTU/hr of all equipment installed in that space. If the volume of your furnace closet is larger, you can put the solid doors on. In all likelihood your space will be way smaller.

If the space is confined, you must provide "two permanent opemings communicating directly with an additional room(s) of sufficient volume so that the combined volume of all spaces meets the criteria for an unconfined space" (quote from my furnace installation manual). Each opening must have a minimum free area of one square inch per BTU/hr but not less than 100 square inches.

You can also add a vent to bring outside air into the furnace closet. There is a table with the required vent size versus BTU/hr, but it is too complicated to easily describe here.

Short answer: Use louvered doors. Make sure you leave enough access to replace either the water heater ot the furnace when needed. I am using four-panel full-louver bifold doors.

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