Is Vent-Free Gas Heating Right For Me?

Click here for a map of states allowing ventfree products
*Several counties and municipalities in Colorado and Utah permit the product. Wisconsin restricts installation in homes built after 1980
Because states, counties and municipalities adopt various codes, please check with your installer or local code officials to assure the current code in the city where you plan to install permits vent-free gas appliances.

The following six model building codes permit the installation of listed vent-free products:
  • National Fire Protection Association (NFPA)
  • Building Officials and Code Administrators (BOCA)
  • Southern Building Code Congress International (SBCCI)
  • Council of American Building Officials (CABO)
  • International Mechanical Code (IMC)
  • International Fuel Gas Code
Only the International Conference of Building Officials-Uniform Mechanical Code (ICBO-UMC) does not permit the product
Other Considerations:
  • Homes of Extremely Tight Construction - if you home shows symptoms of inadequately ventilated home (moisture on inside of windows, mildew, and shower or bath humidity lingers), additional ventilation may be required prior to adding additional  vent-free gas appliances.
  • Homes with Other Fuel Burning Appliances - if there are other fuel burning appliances that use inside air for combustion (i.e. gas ranges, fireplaces, clothes dryers) in the area you plane to operate your vent-free heating product, you must provide adequate fresh air to support the operation of all the appliances. Consult your installer and refer to the Air for Combustion and Ventilation section of the Owners and Installation Manual for your specific vent-free appliance.
  • Homes at High Altitude - (i.e. homes at 4,500 feet above sea level or higher) - may experience nuisance pilot outage and flame shutdown due to lower atmospheric pressure.
  • Bedrooms and Bathrooms - in many areas the installation of vent-free products is permitted up to 10,000 Btu in bedrooms and 6,000 Btu in bathrooms - ANSI Z21.112 Standard and National Fuel Gas Code permit wall mounted installations of vent-free gas heater of 10,000 Btu or less in bedrooms and 6,000 Btu or less in bathrooms.
  • Water Vapor Levels - When outside temperatures fall, so does relative humidity (water vapor). Many people in cold climates use humidifiers to supplement indoor moisture. Vent-Free gas heating products are not intended to replace humidifiers, but they do perform a similar function. AGAR researchers examined relative humidity at 0 degree F outdoor temperature and a 0.25 air change rate ( American Society od Heating Refrigerating and Air Conditioning Engineer's minimum acceptable air change rate is .035/hour). Even under these extreme conditions, the highest relative humidity measured was 49 percent. That's still well below the recognized comfort level of 60 percent.
"Let's Clear the Air" Regarding the Effect of Vent-Free Gas Heaters on Indoor Air  Quality
    In 1995, the scientist at the American Gas Association's Research Division (AGAR) tested the levels of all five major contributors of indoor air quality - oxygen, carbon monoxide, carbon dioxide, nitrogen dioxide and water vapor (humidity) - against the latest Indoor Air Quality (IAQ) guidelines and concluded that vent-free gas heating products performed well within nationally recognized guidelines for indoor air quality.
    This research proves that vent-free gas heating products meets applicable emissions requirements, even when used over extended time periods, among sensitive populations, and even with oversized units.

Combustion by product Specifying agency National IAQ Standard/Guidelines
exposure level/time
Vent-free gas product
Carbon Monoxide (CO) CPSC 15 pp, avg/8 hours
25 ppm avg/1 hour
2.5 ppm/8 hours
1.5 ppm/1 hour
Nitrogen Dioxide (NO2) CPSC 0.3 ppm avg/1 hour 0.22 pm/1 hour
Carbon Dioxide (CO2) OSHA 5000 ppm avg/8 hours 1500 ppm/8 hours
Oxygen (O2) NIOSH 19.5% minimum/continuous 20.4% continuous
Humidity (H2O) ASHRAE 60% maximum/continuous 36.5% maximum
with no condensation

Important Heater Information

  • Installation must be done by qualified service persons.
  • Read Owner's Manual before using.
  • Check local codes and ordinances for permitted uses.
  • Not for use in recreational vehicles.
  • All products approved for manufactured (mobile) home installation.
  • We reserve the right to amend product specifications without notice.
  • Use with adequate air (ventilation) only. Humidifies while it heats.
  • Provides water vapor in the area heated. Refer to owner's manual for specifics.
  • Heating areas based on rooms with 8" ceilings.
  • Operating heater at elevations above 4,500 ft. could cause nuisance outages.
  • Is Vent-Free Gas Heating Right For Me?
  • Product cannot be converted between fuel types.
  • The only warranty available is the Manufacturers standard warranty. Please read the warranty for any limitations or disclaimers. Warranty is provided by the product manufacturer, Master Distributors does not provide warranty or extended warranty programs.
  • All Vent-Free products carry a limited warranty. 
  • All accessories have a limited 30 day warranty.
  • ANSI Z21 11.2 Standard and National Fuel Gas Code revised in 1994 to permit wall mounted installations of vent-free gas heaters of 10,000 Btu or less in bedrooms and 6,000 Btu or less in Bathrooms. As always check local codes
  • States Prohibiting Sale/Use of Vent-Free Products

Technical Tips

Replacement Parts

Home: Contact Us

© 1999--2014 New Beginnings Management Company, Inc.