Non fluorochemical refrigerants, such as ammonia (R717), carbon dioxide (R744) and hydrocarbons such as propane (R290) or isobutene (R600a). These products exist naturally in the environment. Alternative to fluorochemical refrigerants, often used due to their low direct GWP and ODP potential. (However it should be noted that commercial production of natural refrigerants is normally via man-made synthesis).
Air-source heat pumps are more popular in milder winter climates where the temperature is frequently in the range of 4–13 °C (40–55 °F), because heat pumps become inefficient in more extreme cold. This is because ice forms on the outdoor unit's heat exchanger coil, which blocks air flow over the coil. To compensate for this, the heat pump system must temporarily switch back into the regular air conditioning mode to switch the outdoor evaporator coil back to being the condenser coil, so that it can heat up and defrost. A heat pump system will therefore have a form of electric resistance heating in the indoor air path that is activated only in this mode in order to compensate for the temporary indoor air cooling, which would otherwise be uncomfortable in the winter.
*The Wells Fargo Home Projects credit card is issued by Wells Fargo Financial National Bank, an Equal Housing Lender. Special terms apply to qualifying purchases charged with approved credit. The special terms APR will continue to apply until all qualifying purchases are paid in full. Monthly payments of at least 1.90% of the purchase balance are required during the promotional (special terms) period. The APR for Purchases will apply to certain fees such as a late payment fee or if you use the card for other transactions. For new accounts, the APR for Purchases is 28.99%. If you are charged interest in any billing cycle, the minimum interest charge will be $1.00. This information is accurate as of 05/01/2017 and is subject to change. For current information, call us at 1-800-431-5921. Offer expires 6/30/2017.
Heaters exist for various types of fuel, including solid fuels, liquids, and gases. Another type of heat source is electricity, normally heating ribbons composed of high resistance wire (see Nichrome). This principle is also used for baseboard heaters and portable heaters. Electrical heaters are often used as backup or supplemental heat for heat pump systems.
Affton, Arnold, Baden-Riverview, Ballwin, Bellefontaine Neighbors, Belleville, Berkeley, Breckenridge Hills, Brentwood, Bridgeton, Carondelet, Chesterfield, Clayton, Clifton Heights, Collinsville, Creve Coeur, Des Peres, Edwardsville, Ellisville, Eureka, Fairview Heights, Fenton, Ferguson, Florissant, Glen Carbon, Granite City, Hazelwood, High Ridge, Hillsboro, House Springs, Hyde Park, Imperial, Jefferson County, Jennings, Kirkwood, Lake St. Louis, Lemay, Manchester, Maplewood, Maryland Heights, Normandy, O'Fallon (MO), Oakville, Olivette, Richmond Heights, Sappington, Soulard, South Hampton, Spanish Lake, St. Ann, St. Charles, St. Charles County, St. Louis-Downtown, St. Louis Place, St. Peters, Swansea, Tower Grove, Town and Country, University City, Valley Park, Webster Groves, Wentzville, West County, West End, Wildwood