When.com Web Search

Search results

1. Results From The WOW.Com Content Network

2. Central heating - Wikipedia

   en.wikipedia.org/wiki/Central_heating

   Electric heaters are usually part of a fan coil which is part of a central air conditioner. They circulate heat by blowing air across the heating element which is supplied to the furnace through return air ducts. Blowers in electric furnaces move air over one to five resistance coils or elements which are usually rated at five kilowatts.

3. Furnace (central heating) - Wikipedia

   en.wikipedia.org/wiki/Furnace_(central_heating)

   A condensing gas furnace includes a sealed combustion area, combustion draft inducer and a secondary heat exchanger. The primary gain in efficiency for a condensing gas furnace, as compared to a mid-efficiency forced-air or forced-draft furnace, is the capture of latent heat from the exhaust gases in the secondary heat exchanger.

4. Zone valve - Wikipedia

   en.wikipedia.org/wiki/Zone_valve

   Zone valves can also be constructed using wax motors and a spring-return mechanism. In this case, the valve is normally closed by the force of the spring but can be opened by the force of the wax motor. Removal of electrical power re-closes the valve. This style of zone valve operates with a perfectly ordinary SPST thermostat.

5. Thermostat - Wikipedia

   en.wikipedia.org/wiki/Thermostat

   The reversing valve, controlled by the thermostat, causes the change-over from heat to cool. Residential heat pump thermostats generally have an "O" terminal to energize the reversing valve in cooling. Some residential and many commercial heat pump thermostats use a "B" terminal to energize the reversing valve in heating.

6. List of vacuum tubes - Wikipedia

   en.wikipedia.org/wiki/List_of_vacuum_tubes

   High-power RF power tubes are directly heated; the heater voltage must be much smaller than the signal voltage on the grid and is therefore in the 5...25 V range, drawing up to hundreds of amperes from a suitable heater transformer. In some valve part number series, the voltage class of the heater is given in the part number, and a similar ...

7. Reversing valve - Wikipedia

   en.wikipedia.org/wiki/Reversing_valve

   A reversing valve removed from an HVAC heat pump for replacement. A reversing valve is a type of valve and is a component in a heat pump, that changes the direction of refrigerant flow. By reversing the flow of refrigerant, the heat pump refrigeration cycle is changed from cooling to heating or vice versa. This allows a residence or facility to ...

8. Thermostatic radiator valve - Wikipedia

   en.wikipedia.org/wiki/Thermostatic_radiator_valve

   A thermostatic radiator valve on position 2 (15–17 °C) Installed thermostatic radiator valve with the adjustment wheel removed A thermostatic radiator valve (TRV) is a self-regulating valve fitted to hot water heating system radiator, to control the temperature of a room by changing the flow of hot water to the radiator.

9. Annual fuel utilization efficiency - Wikipedia

   en.wikipedia.org/wiki/Annual_fuel_utilization...

   The annual fuel utilization efficiency (AFUE; pronounced 'A'-'Few' or 'A'-'F'-'U'-'E') is a thermal efficiency measure of space-heating furnaces and boilers.The AFUE differs from the true 'thermal efficiency' in that it is not a steady-state, peak measure of conversion efficiency, but instead attempts to represent the actual, season-long, average efficiency of that piece of equipment ...