Vermont Castings Jefferson Vent Free Gas Heater
Installation Requirements
Fresh Air Requirements for Combustion and Ventilation
W A R N I N G
This heater must have fresh air for proper opera- tion. If it does not, poor fuel combustion could result. Read the following instructions to ensure proper fresh air supply for this and other fuel- burning appliances in your home.
Modern construction standards have resulted in homes that are highly
The JUVS heater has specific fresh air require- ments. You must determine that these requirements will be met within the space where the appliance will be installed. The following information will help you insure adequate fresh air is available for the heater to function properly.
Provide for Adequate Ventilation
Any space within a home can be classified in these categories:
1)Unusually tight construction
2)Confined space
3)Unconfined space
First, determine which classification defines the in- tended installation space.
Unusually Tight Construction
You must provide additional fresh air if the space falls into this classification. Unusually Tight Construction is defined as construction wherein:
a. Walls and ceilings exposed to the outside atmo- sphere have a continuous water vapor barrier with a rating of one perm or less, with openings gasketed or sealed, and
b. weather stripping has been added on openable windows and doors and
c. caulking or sealants are applied to areas such as joints around windows and door frames, between sole plates and floors, between wall and ceiling joints, between wall panels, at penetrations for plumbing, electrical and gas lines and at all other openings.
If your home meets all of the above criteria, you must provide additional fresh air for the appliance as detailed
on Page 7.
If your home does not meet the above criteria, follow the procedure below.
Determine If You Have a Confined or
Unconfined Space
Use the following formula to determine if you have a confined or unconfined space.
Space is defined as the room in which you will install the heater, plus any adjoining rooms with doorless passageways or ventilation grilles between the rooms.
The National Fuel Gas Code defines a confined space as a space whose volume is less than 50 cubic feet per 1,000 BTU per hour input rating (4.8m3 per Kw) of the aggregate (total) input rating of all appliances installed in that space and an unconfined space as a space whose volume is not less than 50 cubic feet per 1,000 BTU per hour (4.8m3 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.
1.Determine the volume of space (length x width x height). Include adjoining rooms connected by doorless passageways or ventilating grilles.
Example: A room that is 18’ x 12’ x 8’ has a volume of 1728 cubic feet. An adjoining open kitchen that is 10’ x 12’ x 8’ has a volume of 960 cubic feet. An adjoining open dining room is 12’ x 12’ x 8’ with a volume of 1152 cubic feet. The total volume is 3840 feet. (1728 + 960 + 1152)
2.Divide the volume of space by 50 cubic feet. The result is the maximum BTU/hour the space can support.
Example: 3840 cubic feet divided by 50 = 76.8 or 76,800 BTU/hour.
3.Add the BTU/hour ratings of all
Gas Water Heater | Gas Furnace |
Gas Fireplace Logs | |
Vented Gas Heater* | Other Gas Appliances* |
*Do not include
Example: |
|
Gas Range | 55,000 BTU/hour |
+25,000 BTU/hour | |
Total | 80,000 BTU/hour |
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