Tuesday, July 22, 2008

~SeVen ThInGs YoU ShOuLd KnOw AbOuT aIrCoNd~

With spring here, summer is not that far off. It is time to start thinking about air conditioning. Here are seven things you should know about air conditioning.

1- Air conditioners are made up of two motors, which utilize electrical power. One of them is the compressor, which is the responsible for cooling the air with the refrigerant. The second motor is responsible for moving the air by driving the fan.

2- Your air conditioning costs goes up by about 3% to 4% for every degree that the thermostat is set lower than 78 degrees.

3- Make it a habit to regularly compare the room temperature with the temperature of the air being emitted by the air conditioner. The temperature of the air being emitted by the AC should be approximately 20F lower than the room temperature.

4- An air conditioner effectively dries out the air by converting the water vapor into liquid water. This decreases the humidity and increases the comfort level in the home. In a window unit air conditioner, this water drains out from the rear and in central air conditioning, the water flows to a basement floor drain. Window units have a drip pan at the base and in central air conditioning the drip pan is located beneath the cooling coil, which is inside the ductwork. This drip pan catches the water that flows out and directs it towards the appropriate drain location. Check this water flow. If you can see it going where it is supposed to go, then that’s great. It means your air conditioner is working just the way it is supposed to.

5- You need to make sure that your window units are tilted in such a way that the end that is indoors is higher than the outdoor end so that the water flows outside and not back inside the house ore else you’ll have one enormous mess inside the house. You should also make sure that the water does not drain down the furnace lest the furnace get rusted.

6- Schedule a pre-season maintenance that involves cleaning the drain and the drip pan. Failure to do so could prevent the water from draining. This stagnant water could form ice on the cold coil. As this ice builds up it prevents the outside air from coming in and flowing through the cold coil and thus prevent your air conditioner from functioning efficiently. It could even stop your air conditioner from functioning altogether. As soon as you notice that the air conditioner is not working as efficiently as it should and the house is not cooling down as much as before, you should take immediate action to rectify the situation. This is very easily done- The first thing you should do is turn off the air conditioner. Allow the ice to melt and then fix the drain problem. The AC can now be switched back on.

7- If the air seems to be flowing as it should, but the room does not appear to be getting any cooler, the problem is something other than ice. It could be the level of the refrigerant is low. An air conditioner will keep on running despite low refrigerant levels, but the problem is it does not cool the room down whatsoever. This is a complete waste of electricity.

~HiDe ThIs UgLy ThInG~

You need it. But you don’t have to see it.





1. THE COLOR WRAP
Most window A/Cs have slats or sections of bare plastic that can be covered with wrapping, scrapbook, or printed paper. Use spray mount or double-sided tape.

2. THE CUSTOM CABINET
Environmental therapist Matthew Tudor-Jackson designed a lacquered ash cabinet that hides his A/C and all the cords and cables attached to other living-room electronics. Two slatted doors let cool air out.



3. THE VEIL
Prop stylist Lauren Shields made a short café curtain that sits a third of the way up the window just high enough to cover the A/C. She pulls it aside when the unit is on.




4. THE OBJET D’ART
Designer Jayne Michaels and furniture dealer Larry Weinberg used vintage holed tiles and an iron frame to create a sculpture that stands on a table before the window.
All you need: a meshlike material
that’s nice to look at and lets air through.




5. THE WALL RELIEF
Artist Leslie Fry designed a bas-relief sculpture to fit over her wall-unit A/C. She built a wooden frame, then affixed a cover made from plastic forms found in cookie boxes.

~TiPs FoR bUyInG a NeW aIr CoNdItIoNeR~


  • Don't hire a contractor who wants to size your unit based solely on the floor area of your house. Contractors should calculate how much cooling a home needs according to the guidelines set forth in the Manual J of the Air Conditioner Contractors of America (ACCA). To gather the necessary information, your contractor should spend about an hour poking around your house, taking measurements in each room and asking questions. He or she needs to measure floors, ceilings, and walls--including all the windows--and check insulation in the attic, walls, and crawlspaces. Some other factors that go into the cooling load formula include indoor and outdoor temperatures, number of occupants, shading, and roof color.

  • Insist on getting a copy or computer printout of the cooling load calculations. These can be useful in comparing bids from contractors. Question the contractor if the calculations don't include all the items mentioned above, or if you see anything that you don't understand.

  • Ask your contractor to size the air conditioner based on the latent cooling load (which considers the humidity of the air) as well as the sensible cooling load (which considers the temperature of the air) for your home.

  • Don't be tempted by the lowest bid. Be willing to pay for the time the contractor must spend to do the job right.

  • Check for duct leaks and disconnected ducts. Also be sure air flow is not restricted by ducts that are crushed or too small for the system. Ideally, the contractor should use diagnostic equipment to find leaks and then fix them with quality duct sealants (not duct tape). It doesn't make a lot of sense to buy a larger air conditioner to cool your attic or crawlspace!

  • Buy a high-efficiency unit. New air conditioners are required by federal law to have a SEER of 13 or higher. Even though it will cost more, it's usually worth it to buy at a unit exceeding this value because over time that initial investment will be paid back with energy savings. Look for an ENERGY STAR label when you shop. If you are replacing an existing air conditioner, you must replace the whole unit, including the inside coil and often the blower fan, to achieve the rated efficiency. [Information in this paragraph updated by LBNL to reflect new standards of January 2006]

  • Install for ease of maintenance. Make sure the inside coil can be reached for cleaning. The contractor may have to install an access panel, depending on the model. The coil should be cleaned every two years. The air filter should be located where it is easy to remove. Check it every month during the summer, and clean it or change it whenever it is dirty.

  • Place the outside unit on the north or east side of the house, out of direct sunlight, but don't add shade for it. Leave plenty of room for free air flow on all sides, and leave at least 4 feet of clearance at the top. Keep the area free of debris and shrubbery. The air conditioner draws a lot of air through it. It's more important for the unit to have a lot of space than for it to be well shaded.


Choosing a New Central Air Conditioner

When you buy a new air conditioner, there are three things to remember. Don't buy an oversized unit. Buy an efficient model. And make sure that the unit you buy is installed properly.

Studies show that one third to one half of home air conditioners don't work the way they should because they are oversized. Contractors generally size air conditioners at least a half ton larger than necessary, and often oversize by a ton or more. (We're not talking about the weight of the air conditioner here, but tons of cooling. One ton of cooling is approximately how much cooling you'd get from melting a ton of ice. One ton of cooling is equivalent to about 12,000 Btu of air conditioner capacity.)

An oversized air conditioner turns on and off more often than it should, even during the hottest weather. You pay more for it, and it uses more energy, raising your utility bills. It won't dehumidify the air as well as a smaller system would. It's noisy, especially if the grilles in your house were designed for a smaller unit, as most are. An oversized air conditioner doesn't mean cool comfort for you. It means higher first costs, higher electricity bills, and a home that's uncomfortable to be in.

So make sure that your contractor sizes your air conditioner properly. This should not be done by rule of thumb. Ask your contractor to use the sizing manuals put out by the Air Conditioning Contractors of America (ACCA). Manuals J and S help the contractor size and select equipment; Manual D gives guidance on designing the duct system. The contractor measures your house, notes the window area and the direction the house faces, and measures insulation levels. These data are entered into formulas that are used to calculate the amount of cooling your house needs.

Another important consideration is the ability of the selected air conditioner to remove moisture from the air. Different models have different abilities to handle moisture. The contractor should understand how to pick an air conditioner that is suitable for your house, and for your climate. For more on choosing the best unit for your needs, and on dealing with contractors, see above.

Note: Installation and service charges may be added to these costs.

Source: 1994 Measure Cost Study, California Energy Commission

­Wouldn't it be nice to know how these indispensable machines work their magic?

­ Air conditioners come in various sizes, cooling capacities and prices. One type that we see all the time is the window air conditioner, an easy and economical way to cool a small area:

Window Air Conditioner

People who live in suburban areas usually have one of these in their backyard:

Air Conditioner

If you live in an apartment complex, this is probably a familiar sight:

Air Conditioner

Most businesses and office buildings have condensing units on their roofs, and as you fly into any airport you notice that warehouses and malls may have 10 or 20 condensing units hidden on their roofs:

Air Conditioner

And then if you go around back at many hospitals, universities and office complexes, you find large cooling towers that are connected to the air conditioning system:

Air Conditioner

Even though each of these machines has a pretty distinct look, they all work on the same principles. In this article, we will examine air conditioners -- from small to huge -- so you know more about what you're seeing.