Fans

Ceiling fans should be operated only when the rooms are occupied. A motion sensor or a clear policy of operating ceiling fans only when using the room is needed. Variable speed fans are preferable so that the lowest speed can be used in the heating season to accomplish destratification without causing excessive draft.

• 1.1 Energy use of ceiling fans Ceiling fans use about the same amount of energy as a 100 watt light bulb.

  Ceiling fans permit raising the thermostat setting on an air conditioning system 4 to 6 degrees.

• 1.2 Selecting a ceiling fan

  A good warranty indicates better durability.

  Fans with metal motor housings may require annual oiling while plastic motor housings will not, but may have better warrantees and be worth the added maintenance.

  Blade material will not affect performance.

  Use ceiling fans in heavily used rooms.

  Match the fan size to the room size.

2.0 Whole House Fan

Whole house fans are useful when outdoor temperatures are within the comfort range. The key consideration in our region is the typically high humidity which can postpone nighttime cooling. The high outdoor humidity will also increase the humidity in the home when brought in by the whole house fan. This humidity will reduce the cooling effectiveness of daytime mechanical cooling due to what is termed the latent cooling load. This effectively causes the mechanical cooling to operate more, reducing the net energy savings from using a whole house fan.

• 2.1 Optimum benefits from whole house fans:

A high mass interior and minimal moisture-adsorbing materials (fabric furnishings, draperies, and carpets) increase benefits. (A high mass interior will stabilize temperature swings in any home; see section on Passive Solar Design)

In the heating season, it is important to insulate the whole house fan opening to prevent heat loss.

Minimizing the carpeting in a home is an excellent strategy in reducing the latent cooling load. (Energy savings from a whole house fan can still occur in light frame, conventionally furnished homes.)

Windows should be opened in all the rooms that are to be cooled and the air path to the whole house fan not obstructed by tightly closed doors or other means.

Windows may be opened by controlled mechanical means in conjunction with the fan turning on at certain outdoor temperatures; this can reduce manual operation. In either case, a security concern may necessitate the use of barred window guards. These extra expenses can significantly delay a payback on energy savings.

• 2.2 When to use a whole house fan

  When the outdoor temperatures are below 82 degrees and the relative humidity is less than 75 percent, a whole house fan can cool a house by itself.

• 2.3 Selecting a whole house fan:

  The fan should be sized to accomplish a minimum of one-half air change per minute.

  Use a fan with variable air flow.

  Larger fans are generally quieter than smaller fans, particularly at lower speeds.

  Employ a fire safety feature that will deactivate the fan during a fire.

See "Engineers - Air Conditioning, Heating, and Ventilating" in Yellow Pages

See "Fans - Household," in Yellow Pages

See "Building Materials - Retail" in Yellow Pages

Whole House Fan Contact - George Karonis 29021 Ave Sherman STE 103 Valencia, CA 91355 United States 661-775-5979 1-888-845-6597 1-661-457-3835 http://www.wholehousefan.com Areas Served: North America

Healthy House Technologies Contact - Nazneen Eggleston 26362 Carmel Rancho Lane #213 Carmel, CA 93923 United States 831-625-6345 888-500-VENT 831-625-6346 http://www.healthyhousetechnologies.com Areas Served: North America We sell low Energy/high efficiency Solar attic ventilators and low energy crawlspace fans which cost $7/year in electricity and have a 15 year maintenance free life.

Texas Energy Extension Service
Center for Energy and Mineral Resources
Texas A & M University
College Station, TX 77843-1243
(800) 643-SAVE

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This file last updated on Friday, August 4, 2006