Air-conditioning tips

In medium to large offices, the number of people and presence of equipment and lights all generate extra heat. This adds to the load the cooling cycle of air-conditioning systems has to deal with. That's why even in Australia's coolest cities it takes more energy to cool office blocks over a year than it does to heat them.

Estimating the air-conditioning energy savings due to efficient office equipment is complicated by two factors. Firstly, air-conditioners typically produce two to three units of cooling for every unit of electricity consumed (that is, their coefficient of performance or "COP" is between two and three). So, to remove a kilowatt-hour of heat energy requires between a third and a half a kilowatt-hour of electrical energy. Secondly, in cold weather the heat from office equipment may help heat the building, saving on heating from other sources. However, this is a relatively minor effect.

Once these factors are accounted for, air-conditioning savings from using more efficient office equipment usually bring an extra 20-30% saving in energy costs and greenhouse gas emissions.That is, if an efficient copier saves 1,000 kilowatt hours a year (saving about $150 and generating a tonne less greenhouse gas), additional savings will be up to $45 on air-conditioning costs and 300 kg of greenhouse gas emissions.

Cut Your Cooling Costs With These Money-Saving Tips If you have central air conditioning or a window air conditioning unit, you can cut your electric bills significantly, especially in very warm climates, by following these energy-saving cooling tips this summer.

• When buying a window air conditioning unit, more is not necessarily better. Base the size of the air conditioning unit on the size of the room, the other factors that affect the temperature in the room, such as how many windows it has and whether it faces south, north, etc. An air conditioning unit that is too big for the room will work harder and cost you more.

• When you're shopping for a central air conditioning system, make sure the SEER number (seasonal energy efficiency ratio) is 13 or better (14 in warmer climates). A less efficient system will cost you more to run. Look for an EER (energy efficiency ratio) of 11 or higher for room air conditioners. A high efficiency unit costs more, but if you live in a hot climate, it will pay for itself in a few years by reducing electricity bills.

• Perform regular maintenance on your air conditioning unit. Replace the filter monthly during the cooling season and have a professional service your system at the beginning of each cooling season.

• A cooling system is one of the biggest energy guzzlers in your home (second only to your heating system, depending on where you live). If you have an old air conditioning system with a SEER rating of less than 8, it may be worthwhile to consider replacing it with a more energy efficient system. You should be able to recoup the cost in just a few years.

• Use a programable thermostat so you can vary the Temperature Regulation according to when you're home. Set it to 78 degrees when you're home. If you'll be gone for more than a few hours, it makes sense to set the air conditioning at 85 degrees while you're gone.

• Make sure your air conditioning condenser is located in a shady spot and has room to dispose of the heated air it removes from your house. Don't crowd it with shrubs or anything else.

• Plant shade trees and shrubs around your house to help reduce the heat of the sun, especially on the west and south sides. This can reduce your cooling costs by up to 30%.

• Close drapes on the sunny side of your house.

• Install awnings on the windows on the sunny side of your house.

• Sealing up air leaks in your house will reduce your air conditioning costs as well as heating costs. Caulk or seal places where utilities come into your home (plumbing, electricity, dryer vents, etc.). Fill gaps around chimneys. Weatherstrip around drafty windows and doors.

• Install energy efficient ceiling fans and run them on hot days. If it's just a little too warm for comfort, use the ceiling fan without air conditioning. If it's hot enough to require air conditioning, using the ceiling fans at the same time allows you to raise the temperature setting by five degrees, which will reduce your costs. Use the ceiling fan only when you're in the room, because running the fan doesn't actually lower the temperature. The moving air increases the amount of evaporation from your skin and helps cool you off.

• The darker the color of your house, the more heat it will absorb, so if you're building, buying, or considering repainting, choose lighter colors for the exterior.

• Thirty percent of the heat in your house is absorbed through the roof. Make sure your attic is properly ventilated. Vents in the eaves allows cooler air to enter. A ridge vent or an attic fan can significantly reduce your cooling costs.

• Consider putting reflective window tint on your windows to reduce the amount of heat absorbed.

• Any heat that's generated inside your home has to be removed by your cooling system, so avoid generating heat inside your home whenever possible. Cook on your outdoor grill as often as possible, or use a crockpot and the Microwave Oven. Use the 'air dry' setting on your Dishwasher tips.

• Close off rooms that you aren't using and the cooling ducts to those rooms.

• Make sure the cooled air coming from your air conditioning vents is not obstructed by furniture or draperies.

• Turn off lights when not in use. Lights produce heat, which makes your air conditioning system work harder (and cost more).

• Your computer and other home office equipment also generate heat. Turn them off when not in use.

Also see Tips for buying air-conditioners