HVAC ? Box-in Furnace, how close?

This is a narrow townhome in Balmore, hon, and we want to maximize the amount of space outside the "furnace room."

We are wondering how close we can build the room to the furnace. We will need to leave enough room for servicing and filter changes etc., but are wondering about other obstacles.

Do they need air? Need to breathe?

Safety concerns?

Thanks in advance.

consider the resale a bit - if you put the whole thing together with speed screws and brackets, costs a bit more but disappears real nice when you want to sell the place

Look for the unit lable and it should spec the combustion clearence spec's, usually 2" on the rear of the unit and 1" on the sides. Different units have simular spec's and don't cheat them as there for a good reason.

Most equipment rooms have to be fire rated walls and ceiling. Usually two layers of 1/2" sheet rock for a 1hr fire rating.

Then there's a make up air requirment. Usually combustion air has to be metal duct to with-in 6" of the floor and a room vent opening that extends 12" below the joist. Duct size is determined by the BTU/hr rating.

There's needs to be a unit electrical disconnect with-in sight of the unit.

Gas line shut off needs to be 6" above the floor grade with 6" of easy access clearence to the valve.

This will give you a basic idea of Code requirement but as stated you need to check with your local code enforcement for the current codes for your area as they will probably be more restrictive than what I've stated.

T_Bone

1. Clearance for service and maintenance. You stated you will keep space for filter removal and in front of access panels.

2. Clearance to Combustibles. This requirement should be on the nameplate of the furnace, but if you left room for number 1, you will probably be OK.

3. Yes, they do need adequate air to support combustion, If it is a "hi-E" type furnace with PVC flue out a sidewall it most likely also has a PVC combustion air inlet. If it is not that type, you will need to provide grilles/door louvers/etc. The minimum size of these type openings is governed by code.

It was good advice to give a courtesy call to your local code official to make sure you don't have some unique local requirements also.

As usual YMMV,

Kirk

Valid point, but we are jsut in the planning stage. Trying to see if it is even possible.

I should mention that this is electric ignition (no pilot) and the airhandler is on top (integral).

Anyone have a rough idea on code/best practices?

Thanks,
Joe

Yes, go talk to HVAC people and see if they have any specifics for your area, preferably a dealer for the type of units you have.

Charles