Some homeowners are initially inclined to select fiberglass insulation since that is what they are most familiar with and because it is relatively inexpensive. However, you should consider all your options before making a choice.

Polyurethane foam insulation is rapidly gaining in popularity as its benefits become more widely acknowledged. While its upfront costs may be a little higher than fiberglass, foam insulation is considered to provide a better quality insulating barrier than other options, ultimately saving homeowners money through reduced energy costs over time. Spray foam insulation is uniquely suited to fill small areas that may be difficult or impractical to reach with fiberglass. Foam insulation is sprayed into the uninsulated area, such as an attic, basement or wall cavity, and expands to fill every recess and crack, thus creating a truly airtight seal.

While there are do-it-yourself foam kits available, polyurethane insulation should be handled carefully and it is highly recommended to hire a spray foam professional for the application. In addition to alleviating safety concerns, professional installation will ensure that the spray foam is applied properly in order to provide the most energy efficiency and also to reduce wasted product.

Spray polyurethane foam insulation provides many advantages over alternative options, making it the superior choice when selecting an insulating material. Although it may require a slightly higher upfront cost than fiberglass, foam will make up for that difference over the long run with increased savings on heating and cooling costs as well as less maintenance.

Carrier realized he’d developed something with far-reaching potential, and it wasn’t long before air-conditioning systems started popping up in theaters and stores, making the long, hot summer months much more comfortable.

The actual process air conditioners use to reduce the ambient air temperature in a room is based on a very simple scientific principle. The rest is achieved with the application of a few clever mechanical techniques. Actually, an air conditioner is very similar to another appliance in your home — the refrigerator. Air conditioners don’t have the exterior housing a refrigerator relies on to insulate its cold box. Instead, the walls in your home keep cold air in and hot air out.

Air-conditioning Basics

Air conditioners use refrigeration to chill indoor air, taking advantage of a remarkable physical law: When a liquid converts to a gas (in a process called phase conversion), it absorbs heat. Air conditioners exploit this feature of phase conversion by forcing special chemical compounds to evaporate and condense over and over again in a closed system of coils.

The compounds involved are refrigerants that have properties enabling them to change at relatively low temperatures. Air conditioners also contain fans that move warm interior air over these cold, refrigerant-filled coils. In fact, central air conditioners have a whole system of ducts designed to funnel air to and from these serpentine, air-chilling coils.

When hot air flows over the cold, low-pressure evaporator coils, the refrigerant inside absorbs heat as it changes from a liquid to a gaseous state. To keep cooling efficiently, the air conditioner has to convert the refrigerant gas back to a liquid again. To do that, a compressor puts the gas under high pressure, a process that creates unwanted heat. All the extra heat created by compressing the gas is then evacuated to the outdoors with the help of a second set of coils called condenser coils, and a second fan. As the gas cools, it changes back to a liquid, and the process starts all over again. Think of it as an endless, elegant cycle: liquid refrigerant, phase conversion to a gas/ heat absorption, compression and phase transition back to a liquid again.

It’s easy to see that there are two distinct things going on in an air conditioner. Refrigerant is chilling the indoor air, and the resulting gas is being continually compressed and cooled for conversion back to a liquid again. On the next page, we’ll look at how the different parts of an air conditioner work to make all that possible.

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In this article the term air conditioner will apply to a heat pump or a standard air conditioner. Both benefit equally from annual service tune-ups.

An air conditioner is a very tough piece of equipment. It is engineered to withstand all sorts of abuse and keep on running. This is great in most respects, but it can lead to complacency about maintenance. Like a car, air conditioners need regular tune-ups to run properly.

Without regular maintenance an air conditioner loses about 5% of it’s original efficiency for each year of operation. This means that the 12 SEER unit that you bought just a few years ago may be functioning like a 9 SEER unit today! The good news is that you can recover most of that lost efficiency through regular maintenance. Studies show that with regular tune-ups a unit will maintain up to 95% of it’s original efficiency. This means that the cost of an annual tune-up is recovered very quickly in savings on your monthly electric bill and reduced repair costs. A properly serviced air conditioner will also do a better job of dehumidifying your home.

Many local air conditioning firms offer special prices at this time of the year. Some even offer annual service programs that insure that you will be reminded of the need to service the unit at the beginning of the cooling and heating seasons.

The service check should include cleaning the condensing unit coils, checking the amp draw of the compressor, oiling the fan motors, checking that belts are well adjusted, and checking the system operating pressures and temperatures against the manufacturers specifications. One of the most important items to check is the coolant level (commonly known as Freon) in the air conditioner. A system that is only 10% low on coolant will cost about 20% more to operate! The Air Conditioning Contractors of America (ACCA) recommends that coolant levels be checked every year.

If your unit is low on coolant, and more must be added, there are new laws governing its use. Freon is a chlorofluorocarbon (CFC) that will damage the Earths protective ozone layer if released into the atmosphere. The laws governing CFC’s now do not allow your air conditioner contractor to add Freon to a leaky system. [Ed note: CFCs are no longer allowed and various alternative refrigerants are now common.] They are first required to find and fix the leak in the system. Don’t ask them to violate this law as they may lose their license if they are caught doing this.

There are some things in addition to yearly tune-ups that you can do to help ensure a high level of comfort and proper system operation. First, buy good filters and change them regularly. Next, keep bushes and other materials away from the outside unit of your air conditioner. Another good idea is to avoid closing supply air outlets in your house. In almost all cases, closing supply outlets is harmful to the operation of the overall system.

All equipment, even the most reliable, needs routine maintenance. Complicated equipment like today’s air conditioners benefit in many ways from annual service. They recover much of their lost efficiency, they are less likely to suffer a major break down, they have a longer life span, they increase your comfort, and they operate for less money.

Article By Doug Garrett