Installation Guide

SECTION VIII

PRODUCING ADEQUATE AIR FOR COMBUSTION AND VENTILATION

This section is for residential or manufactured (mobile) installation

“This heater shall not be installed in unusually tight construction unless provisions are adequate for combustion

and ventilation air.”

NOTE: This heater shall not be installed in a room or space unless the required volume of indoor combustion

air is provided by the method in National Fuel Gas Code, ANSIZ223.1/NFPA 54, the International Fuel Gas

Code, or applicable codes.

National Fuel Gas Code, ANSI Z223.1/NFPA 54 deﬁ nes unusually tight construction or unconﬁ ned space as

a space whose volume is less than 50 cubic feet per 1,000 BTU per hour (4.8m 3 per kw) of aggregate input

rating of all appliances installed in that space and an unconﬁ ned space as a space whose volume is not

less than 50 cubic feet per 1,000 BTU per hour (4.8m 3 per kw) of aggregate input rating of all appliances

installed in that space. Rooms communicating directly with space in which appliances are installed, through

openings not furnished with doors, are considered a part of unconﬁ ned space. Unusually tight construction

is deﬁ ned as construction where:

A. Walls and ceilings exposed to the outside atmosphere have a continuous water vapor retarder with a

rating of 1 perm (6 x 10-11kg per pa-sec-m2) or less with openings gasketed or sealed.

B. Weather stripping has been added on openable windows and doors.

C. Caulking or sealants are applied to areas such as joints around window and door frames, between

sole plates and ﬂ oors, between wall-ceiling joints, between wall panels, at penetrations for plumbing,

electrical and gas lines and at other openings.

NOTE: SOME AREAS IN THE UNITED STATES HAVE HIGHER REQUIREMENTS FOR CUBIC FEET PER 1000 BTU/ HOUR

INPUT. (EX. CINCINNATI, OHIO CODES REQUIRE 70 CUBIC FEET). CHECK YOUR LOCAL CODE BEFORE INSTALLATION

DETERMINING FRESH-AIR FLOW FOR HEATER LOCATION

Determine if you have unusually tight construction or unconﬁ ned space. Use this worksheet to determine if

you have unusually tight construction or unconﬁ ned space. Space: includes the room in which you will install

heater plus adjoining rooms with doorless passageways or ventilation grills between the rooms.

“WARNING: IF AREA IN WHICH HEATER MAY BE OPERATED DOES NOT MEET THE REQUIRED

VOLUME FOR INDOOR COMBUSTION AIR, COMBUSTION AND VENTILATION AIR SHALL BE

PROVIDED BY ONE OF METHODS DESCRIBED IN NATIONAL FUEL GAS CODE, ANSI Z223.1/

NFPA 54, THE INTERNATIONAL FUEL GAS CODE OR APPLICABLE CODES.”

“WARNING: IF AREA IN WHICH HEATER MAY BE OPERATED IS SMALLER THAN THAT DEFINED AS

AN UNCONFINED SPACE OR IF BUILDING IS OF UNUSUALLY TIGHT CONSTRUCTION, PROVIDE

ADEQUATE AIR FOR COMBUSTION AND VENTILATION BY ONE OF METHODS DESCRIBED IN

NATIONAL FUEL GAS CODE, ANSI Z223.1/NFPA 54 AIR FOR COMBUSTION AND VENTILATION

OR APPLICABLE LOCAL CODES.”