Vermont Casting Vent Free Features, Fresh Air Requirements for Combustion Ventilation

Vermont Castings Jefferson Vent Free Gas Heater

Vent Free Features

The JUVS Gas Heater is an unvented gas appliance tested and listed to the ANSI standard Z21.11.2a.2001. The Vent Free Gas Heater is configured to use Natural Gas, (JUVSRN, JUVSMN ) or Propane (JUVSRP, JUVSMP). Because these heaters are clean-burning and highly energy-efficient, no venting system is required.

The JUVS is shipped fully assembled with the exception of the log set. The log set is assembled during installation.

The JUVS is equipped with a Honeywell control valve that allows thermostatic control, on/off switch or a remote switch (not supplied).

The JUVS model incorporates variable regulators that allow you to adjust burner heat output between HIGH, (28,000 BTU), and LOW, (20,000 BTU). See the Operation Section for details.

The standing pilot incorporates an Oxygen Depletion System (ODS/pilot) which shuts off gas flow to the burner in the event that sufficient fresh air becomes unavailable for continued safe operation.

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 energy-efficient and that allow little heat loss. Your home needs to breathe, however, and all fuel-burning appliances need fresh air to function properly and safely. Exhaust fans, clothes dryers, fireplaces and other fuel burning appliances use the air inside the building. If the available fresh air supply is insufficient to meet the demands of these appliances, problems can result.

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)

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