NOTE: DIAGRAMS & ILLUSTRATION NOT TO SCALE.
4
Your options are:
a. Rework equations adding the space of ad-
joining 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
1992, Section 5.3.
b. Vent room directly to the outdoors. Refer to
National Fuel Gas Code, ANSI Z223.1 1992,
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 uncon-
fined space.
LOCATION OF FIREPLACE
Carefully select the best location for installa-
tion of your VF4000 series Unvented Room
Heater. The following factors should be taken
into consideration:
• Clearance to side wall, ceiling, woodwork
and windows.
• Location must not be affected by drafts
caused by kitchen exhaust fans, return air reg-
isters for forced air furnaces/air conditioners,
windows or doors.
• Installation must provide adequate ventila-
tion and combustion air.
• Do not install the VF4000 series heaters in a
sleeping room or bathroom.
• Never obstruct the front opening of the heater
or restrict the flow of combustion and ventila-
tion air.
• This appliance may be installed in an after-
market* manufactured (Mobile) Home, where
not prohibited by state or local codes.
*Aftermarket: Completion of sale, not for pur-
pose of resale, from the manufacturer.
• Minimize modifications to existing construc-
tion. Refer to
Figure 1 for location suggestions.
Figure 1
To ensure even heat distribution, it is best to
position the heater centrally against the longest
wall of the room. Make sure there is adequate
ventilation where the heater is installed. The
gas appliance will shut off if the oxygen level
falls below 18%.
These appliances are uniquely suited for instal-
lations requiring a utility shelf positioned di-
rectly above the fireplace. Utility shelves like
these are commonly used for locating televi-
sion sets and decorative plants.
To provide for the lowest possible shelf sur-
face, combustible materials used to support a
utility shelf directly above these appliances
should be positioned just above the appliance
top spacers. The minimum height from the
base of the VF4000 to the underside of com-
bustible materials used to construct a utility
shelf is 37-1/4” (946 mm).
The appliance should be mounted on a fully
supported base extending the full width and
depth of the unit. The appliance may be located
on or near conventional construction materi-
als. However, if installed on combustible mate-
rials, such as carpeting, vinyl tile, etc., a metal
or wood barrier covering the entire bottom
surface must be used.
If the appliance is to be elevated above floor
level, a solid continuous platform must be
constructed.
WARNING: MAINTAIN MINIMUM
CLEARANCES.
WARNING: IF THE AREA IN WHICH THE
HEATER MAY BE OPERATED IS SMALLER
THAN THAT DEFINED AS AN UNCON-
FINED SPACE, PROVIDE ADEQUATE
COMBUSTION AND VENTILATION AIR BY
ONE OF THE METHODS DESCRIBED IN
THE NATIONAL FUEL GAS CODE, ANSI
Z223.1 1992, SECTION 5.3 OR APPLI-
CABLE LOCAL CODES.
Use the following equations to determine if you
have a confined or unconfined space.
1. Determine the volume of space — ft
3
.
Length x Width x Height = _____ ft
3
(Include adjoining rooms with doorless pas-
sageways or ventilation grills between
rooms.)
Example: 20' (L) x 16' (W) x 8' (H) = 2560 ft
3
2. 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: 2560 ft
3
/ 50 ft
3
= 51.2
or 51,200 BTU/Hr the space can support.
3. Add the BTU/Hr of all the fuel burning appli-
ances in the space.
Vent-Free heater
_______
BTU/Hr
Gas appliance #1*
_______
BTU/Hr
Gas appliance #2
+ _______
BTU/Hr
Total = _______
BTU/Hr
Example:
VF4000 Vent-free heater 25,000
BTU/Hr
Gas appliance #1
34,000
BTU/Hr
(water heater)
Total =
59,000
BTU/Hr
* Do not include direct-vent gas appliances.
Direct-vent is sealed combustion and draws
combustion air from the outdoors.
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:
51,200
BTU/Hr
(max. the space can support)
59,000
BTU/Hr
(actual amount of BTU/Hr used)
The space in the above example is a confined
space because the actual BTU/Hr used is more
than the maximum BTU/Hr the space can sup-
port. You must provide additional fresh air.
