WATER VAPOR: A BY-PRODUCT OF UNVENTED ROOM HEATERS

Water vapor is a by-product of gas combustion.An unvented room heater produces approximately one (1) ounce (30ml) of water for every 1,000 BTU's (.3KW's) of gas input per hour.

Unvented room heaters must be used as supplemental heat (a room) rather than a primary heat source (an entire house). In most supplemental heat applications, the water vapor does not create a problem. In most applications, the water vapor enhances the low humidity atmosphere experienced during cold weather.

The following steps will help insure that water vapor does not become a problem.

1.Be sure the heater is sized properly for the application, including ample combustion air and circulation air.

2.If high humidity is experienced, a dehumidifier may be used to help lower the water vapor content of the air.

3.Do not use an unvented room heater as the primary heat source (an entire house).

PROVISIONS FOR ADEQUATE COMBUSTION & VENTILATION AIR

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 defines a confined space as a space whose volume is 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 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.

The following example is for determining the volume of a typical area in which the VFCM-25 may be located and for determining if this area fits the definition of an unconfined space.

The maximum input of the VFCM-25 is 25,000 Btu per hour. Based on the 50 cubic feet per 1,000 Btu per hour formula, the minimum area that is an unconfined space for installation of the VFCM-25 is 1,250 cubic feet, 50 cubic feet x 25 = 1,250 cubic feet. To determine the cubic feet of the area in which the VFCM-25 is to be installed, measure the length, width and height of the area. Example: The area measures 16 feet in length, 10 feet in width and 8 feet in height, the area is 1,280 cubic feet. The VFCM-25 can be installed in this unconfined space with no requirement to provide additional combustion and ventilation air.

Warning: 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, Section 5.3 or applicable local codes.

Unusually Tight Construction

The air that leaks around doors and windows may provide enough fresh air for combustion and ventilation. However, in buildings of unusually tight construction, you must provide additional fresh air.

Unusually tight construction is defined as construction where:

a.Walls 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.Weatherstripping has been added on openable 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 wall-ceiling joints, between wall panels, at penetrations for plumbing, electrical, and gas lines, and at other openings.

If the heater is installed in a building of unusually tight construction, adequate air for combustion, ventilation and dilution of flue gases shall be provided in accordance with ANSI Z223.1/NFPA54.

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Empire Comfort Systems VFCT25-3, VFCM-25-3. VFCR-25-3 Water Vapor a BY-PRODUCT of Unvented Room Heaters
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VFCT25-3, VFCM-25-3. VFCR-25-3 specifications

Empire Comfort Systems has long been recognized for its commitment to delivering high-quality heating products that cater to a variety of residential and commercial needs. Among their offerings, the VFCM-25-3, VFCR-25-3, and VFCT-25-3 stand out as exceptional models in the realm of vent-free gas fireplaces. These units are designed to provide warmth and comfort while boasting innovative technologies, efficiency, and user-friendly features.

The VFCM-25-3 model is particularly notable for its contemporary design, offering a sleek appearance that can complement various home decors. It utilizes a dual fuel system, allowing it to run on both natural gas and propane. This flexibility ensures that users have options based on their heating preferences and availability of fuel sources. The in-built thermostat control enables automatic adjustments to maintain a consistent temperature, providing comfort without the need for constant monitoring.

Meanwhile, the VFCR-25-3 model focuses on efficiency and an elegant, traditional style. It incorporates Empire's cutting-edge technology that allows for a quick and efficient heat production. Featuring a unique safety pilot system, the VFCR-25-3 automatically shuts off the gas supply in case of a malfunction, ensuring peace of mind for homeowners. Additionally, this model is equipped with a ceramic burner that produces realistic flame patterns, creating a warm ambiance in spaces of various sizes.

The VFCT-25-3 variant is designed with versatility and user convenience in mind. This model comes with vent-free technology that allows for installation in locations where venting would be challenging or impossible. Its adjustable flame height allows users to customize the experience, creating a customizable ambiance that caters to personal preferences. Moreover, the unit is equipped with a built-in oxygen depletion sensor (ODS) that ensures safe operation by shutting off the unit if oxygen levels drop to unsafe levels.

All three models share common features like easy installation, thermal efficiency, and low emissions, making them environmentally friendly options. They are perfect for both supplemental and primary heating, providing comfort during the cold winter months without the need for extensive alterations to existing structures. Empire Comfort Systems continues to lead the market with innovative solutions that prioritize warmth, safety, and aesthetic appeal. Whether you choose the VFCM-25-3, VFCR-25-3, or VFCT-25-3, you can be assured of quality comfort and reliability for years to come.
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