Hearth and Home Technologies NDV4236I, NDV3630 B. Constructing the Appliance Chase, C. Clearances

B. Constructing the Appliance Chase

A chase is a vertical box-like structure built to enclose the gas appliance and/or its vent system. In cooler climates the vent should enclosed inside the chase.

NOTICE: Treatment of ceiling firestops and wall shield firestops and construction of the chase may vary with the type of building. These instructions are not substitutes for the requirements of local building codes. Therefore, you MUST check local building codes to determine the requirements to these steps.

Chases should be constructed in the manner of all outside walls of the home to prevent cold air drafting problems. The chase should not break the outside building envelope in any manner.

Walls, ceiling, base plate and cantilever floor of the chase should be insulated. Vapor and air infiltration barriers should be installed in the chase as per regional codes for the rest of the home. Additionally, in regions where cold air infiltration may be an issue, the inside surfaces may be sheetrocked and taped for maximum air tightness.

To further prevent drafts, the wall shield and ceiling fire- stops should be caulked with high temperature caulk to seal gaps. Gas line holes and other openings should be caulked with high temp caulk or stuffed with unfaced insu- lation. If the appliance is being installed on a cement slab, a layer of plywood may be placed underneath to prevent conducting cold up into the room.

C. Clearances

NOTICE: Install appliance on hard metal or wood surfaces extending full width and depth. DO NOT install directly on carpeting, vinyl, tile or any combustible material other than wood.

WARNING! Risk of Fire! Maintain specified air space clearances to appliance and vent pipe:

•Insulation and other materials must be secured to prevent accidental contact.

•Failure to maintain airspace may cause overheating and a fire.

1/2 in.

(13 mm)

1/2 in.

(13 mm)

Drywall

0 in.

Combustible flooring may be installed next to the front of the appliance.

Note: If the inside of the framed cavity is to be finished, the framing dimensions must include the finished surface.

If drywall is to be attached to the rear wall, the depth must be measured from the drywall surface.

D

Clearance to Ceiling

30 in. (762 mm)

Object	36 in.
Combustible	(914 mm)

0 in. TO LEVEL OF STANDOFFS

B

0 in.	C
	A

	A	B	C	D
	Rough Opening	Rough Opening	Rough Opening	Rough Opening
Model	(Width)	(Height)	(Depth)	(DVP Pipe)
NDV3630	36 in./914 mm	34-7/8 in./886 mm	19-5/8 in./498 mm	10 in./254 mm
NDV3933	39 in./991 mm	34-7/8 in./886 mm	19-5/8 in./498 mm	10 in./254 mm
NDV4236	42 in./1067 mm	34-7/8 in./886 mm	19-5/8 in./498 mm	10 in./254 mm
NDV4842	48 in./1219 mm	34-7/8 in./886 mm	19-5/8 in./498 mm	10 in./254 mm

Figure 5.2 Clearances to Combustibles

Heatilator • Novus NDV Series • 4055-187 Rev F • 06/08 19