Example:
Vent-free heater #1 9,000
BTU/Hr
Vent-free heater #2 23,000
BTU/Hr
Gas appliance #1 35,000
BTU/Hr
(water heater)
Total = 67,000
BTU/Hr
* Do not include direct-vent gas appliances. Direct-vent is sealed
combustion and draws combustion air from the outdoors.
The space in the previous example is a confined space because the actual
BTU/Hr used is more than the maximum BTU/Hr the space can support.
You must provide additional fresh air. Your options are:
a.
Rework equations adding the space of adjoining room(s). If the extra
volume provides an unconfined space, then remove door or add ventilation
grills between rooms. Refer to National Fuel Gas Code, ANSI Z223.1,
Section 5.3.
b.
Vent room directly to the outdoors. Refer to National Fuel Gas Code,
ANSI Z223.1, Section 5.3.
c.
Install a lower BTU/Hr heater, to make the area an unconfined space.
If the actual BTU/Hr used is less than the maximum BTU/Hr the space can
support, then the space is an unconfined space. You will need no additional
fresh air ventilation for an unconfined space.
This appliance is designed to be wall-hung. Do not recess any part of
the appliance into the wall. This appliance may be installed in any
room in a home except bathrooms - or areas where large amounts of
steam are likely to be generated.
It should be noted that heaters create warm air currents. These
currents move heat to wall surfaces next to the heater. Installing
the heater next to vinyl or cloth wall coverings or operating the
heater where impurities in the air (such as tobacco smoke or
candle smoke) exist, may discolour walls.
Installation in living rooms is common, however other rooms such as
kitchens, dining rooms and hallways are permitted, providing a suitable
natural gas supply is available, and rooms sizing and ventilation
requirements are strictly adhered to (see section 4).
The appliance is designed to be versatile, and as such will operate correctly
when exposed to normal gentle drafts experienced within the home. It is not
recommended, however that the appliance be installed in areas where it is
likely to be exposed to persistent strong drafts, that may be generated by
outside doors or windows, air vents etc. It is recommended that the
appliance should not be installed within 20” of any air vent.
4
5.0 CODES
Adhere to all local codes or in their absence the latest edition of The
National Fuel Gas Code ANSI Z223.1 or NFPA54 which can be obtained
from The American National Standards Institute, Inc. (1430 Broadway, New
York, NY, 10018) or National Fire Protection Association, Inc. (Batterymarch
Park, Quincy, MA, 02269).
Seller of unvented natural gas fired supplemental room heaters in the
commonwealth of Massachusettes shall provide to each purchaser a copy
of 527 CMR 30 upon sale of the unit. Please refer to section 4.0 on page 2
of this manual.
This Lennox Hearth Products unvented gas room heater is certified by
OMNI-Test Laboratories, Inc to ANSI Z21.11.2b-2004 standard.
This heater shall not be installed in a confined space or unusually tight
construction unless provisions are provided for adequate combustion and
ventilation air.
The
National Fuel Gas Code, ANSI Z223.1/NFPA 54
defines a confined
space as a space whose volume is less than 50 ft
3
per 1,000 BTU/Hr (4.8
m
3
per kW) of the aggregate input rating of all appliances installed in that
space and an unconfined space as a space whose volume is not less than
50 ft
3
per 1,000 BTU/Hr (4.8 m
3
per kW) of the aggregate input rating of all
appliances installed in that space.
Rooms communicating directly with the space in which the appliances are
installed, through openings not furnished with doors, are considered a part
of the unconfined space.
Unusually tight construction is defined as construction where:
a.
wall and ceilings exposed to the outside atmosphere have a continuous
water vapor retarder with a rating of one perm or less with openings
gasketed or sealed, and
b.
weather stripping has been added on operable windows and doors, and
c.
caulking or sealants are applied to areas such as joints around window
and door frames, between sole plates and floors, between wallceiling joints,
between wall panels, at penetrations for plumbing, electrical, and gas lines,
and at other openings.
Use the following equations to determine if you have a confined or
unconfined space.
Determine the volume of space — ft
3
.
Length x Width x Height = _____ ft
3
(Include adjoining rooms with doorless passageways or ventilation
grills between rooms.)
Example:
24' (L) x 16' (W) x 8' (H) = 3072 ft
3
Divide the volume of space by 50 ft
3
to determine the maximum
BTU/Hr the space can support.
______ (volume of space – ft
3
)/ 50 ft
3
=
(Maximum BTU/Hr the space can support)
Example:
3072 cu ft 3 / 50 ft 3 = 61.44
or 61,440 BTU/Hr the space can support.
Add the BTU/Hr of all the fuel burning appliances in the space.
Vent-Free heater
_______ BTU/Hr
Gas appliance #1* _______ BTU/Hr
Gas appliance #2 + _______ BTU/Hr
Gas appliance #3 + _______ BTU/Hr
Total =
_______ BTU/Hr
1.
2.
3.
6.0 COMBUSTION AND VENTILATION AIR
4.
Compare the maximum BTU/Hr the space can support with the
actual amount of BTU/Hr used.
_______ BTU/Hr (max. the space can support)
_______ BTU/Hr (actual amount of BTU/Hr used)
Example:
61,440
BTU/Hr (max. the space can support)
67,000 BTU/Hr (actual amount of BTU/Hr used)
7.0 SITE REQUIREMENTS
IF THE AREA IN WHICH THE HEATER MAY BE OPERATED IS
SMALLER THAN THAT DEFINED AS AN UNCONFINED
SPACE OR IF THE BUILDING IS OF UNUSUALLY TIGHT
CONSTRUCTION, PROVIDE ADEQUATE COMBUSTION AND
VENTILATION AIR BY ONE OF THE METHODS DESCRIBED
IN THE NATIONAL FUEL GAS CODE, ANSI Z223.1/NFPA 54,
SECTION 5.3 OR APPLICABLE LOCAL CODES.
WARNING
