Room Air Conditioner Efficiency, Use and Maintenance Tips Tips on Cooling Capacity: How many BTUs do I need? It is extremely important to choose a room air conditioner of proper cooling capacity. A unit with too much cooling capacity will be inefficient and expensive to operate. A unit that’s too small won’t do a satisfactory job. To determine the best sized air conditioner for your room, click here  for our room calculator worksheet. There is also a close relationship between cooling capacity and dehumidifying the air. An oversized unit will quickly cool the air without remaining in operation long enough to dehumidify it, and a “cold, clammy” feeling will result. After determining the size unit needed, consider its operating efficiency. An efficient room air conditioner uses less electricity, so it costs less to operate. To measure efficiency, engineers have established a room air conditioner Energy Efficiency Ratio (EER). It is computed by dividing Btu/h (cooling output) by the watts of power (electrical input) in accordance with U.S. Department of Energy Test Procedures.

Federal Trade Commission regulations require that this value be placed on the label attached to the product. Thus, a 12,000 Btu/h model might use 1,900 watts and have an EER of 6.3, while another model of the same capacity might use 1,350 watts and have an EER of 8.8. The higher EER is the more efficient of the two. AHAM’s searchable directory lists EER’s for all units. Before installing room air conditioners, check your home wiring for the right circuit amperage and voltage. Avoid lines already loaded with appliances. Do not connect a 208-V unit to a 115-V line or a 115-V unit to higher lines. If a fuse blows, shut off the unit and check load and wiring. Be sure the outlet is properly grounded. Never remove the grounding prong from the plug. Install the unit in a shaded window, if possible. Keep warm air out by weather stripping doors and windows and keeping them tightly closed. Close fireplace dampers and seal openings to the attic or other uncooled areas. Seek professional advice on recommended ceiling and wall insulation.

Tips for Energy Efficiency and Maintenance Turn off the unit and open doors and windows during cooler periods. Use the unit fan and portable fans to draw in cooler outside air and increase circulation. Although air conditioners also dehumidify, a dehumidifier in the basement can prevent excess moisture seepage through the house. Use a higher (warmer) thermostat setting during peak periods or when the area is unoccupied. A setting of 75 to 80 degrees will cut power consumption by 15 percent. Don’t let heat build up all day and then try to cool areas quickly by turning the controls to maximum settings. Start units earlier in the day and cool areas slowly before they are occupied. Avoid activities that generate high heat and humidity (i.e., cooking, bathing and laundering) during high heat hours. Draw the shade or window blinds to reduce solar and outdoor heat. Reflecting and double-pane glass, awnings, overhangs, louvered sunscreens, plantings, fences or adjoining buildings also help ─ but be sure not to block the back of the unit.

Regularly change or clean filters, and check air flow for blockage and evaporator coil for frost. Use a vacuum cleaner attachment to clean accessible parts but be careful not to damage them. Have the unit checked and cleaned at the start of the season. During the off season, make certain it is cleaned and properly covered and disconnected.3 Tips for Taking Care of Window Air Conditioner Units Yesterday, we featured 5 Tips for Annual Air Conditioner Maintenance. ac unit floorIt was a helpful article for anyone with central A/C, but Unplggd reader Amanda H pointed out that we completely neglected many small, cool dwellers with window or free-standing air conditioning units.side opening window ac unit Just like any other appliance in your place, the window A/C also needs tender love and care. how to make an air conditioner with a fan

Make sure to give it a thorough cleaning at least once a year: 1. Wash the filter. The main thing to do to upkeep your window unit is to make sure you wash the filter screen on a regular basis. After popping out the front grill of the unit with a putty knife, remove the mesh filter. Wash it together with the grill in a mixture of warm, soapy water and bleach to remove any mold. 2. Clean the coils. You'll find evaporator coils underneath the filter. To keep your A/C going strong, you'll want to vacuum them thoroughly using a brush attachment. Remove any stubborn dirt with a plastic scrub brush. Do the same thing with the condenser coils at the back of the A/C unit. The idea is that extra debris gets in the way of air flow—an your cool air. Use a fin comb to straighten any bent coil fins. You can find fin combs at a home or hardware store or online for around $10. (Image: Flickr user skeddy in NYC under license from Creative Commons.)Installing Air Conditioning Unit

Before Purchase or Installation Calculate the size of room to be cooled so that you buy an AC unit with enough capacity. Obtain permission for installation from building management. Make sure that electrical service is adequate. AC units should have dedicated outlets. Ensure that the window and frame where the unit will be installed are in good condition. Follow the manufacturer's instructions. Make sure the unit is installed securely. Support the unit from underneath, or firmly fasten it from inside with angles. You may use metal brackets, mounting rails, etc. Supporting metal brackets, interior angles, etc. should be structurally fastened to the building and must be strong enough for the size and weight of the AC unit. Objects or shims used to adjust the position of the AC unit must have an independent source of fastening or attachment. Secure leveling objects to prevent movement and shifting due to vibrations from the AC unit, wind and other weather conditions.