The purpose of this document is to assist those who may want to add a window air-conditioning unit in their off-campus unit. This is not permitted where Caltech has provided air-conditioning. Caltech sells only casement style a/c units for use in the on campus dormitories. We sell no other a/c units. Prior to your purchase of any air conditioning unit, you must call Housing Maintenance at 626-395-6175 and have them site inspect to ensure you have the electrical power needed to operate a window a/c. If it is determined that the electrical service cannot handle the additional load of adding an air conditioner, Caltech will make no changes in order to accommodate an air conditioner.

If you are able to install an air conditioner, Caltech must install it. You will be charged the exact labor rate for installation. The average labor cost for this installation is $45.00. The average labor rate per hour per man is $30.00.

Here are some helpful hints on purchasing a window air-conditioning unit for use in an off campus unit.

Window unit:
The window unit is (usually) easy to install into any standard double-hung window. It should offer multiple cooling options (low - high). This is the kind that most people get because it's the cheapest.
Cost: $250-$800
Weight: approximately 120 lbs.

Before you get ready to go shopping, it's a good idea to check out Consumer Reports or some other product-rating publication so you know which models are recommended based on what you're considering buying. Don't select a no-name brand without researching it or you won't know what kind of quality and durability you're getting. If you aren't interested in hunting down air conditioner brand ratings, then pick a brand you already trust, such as General Electric, Amana, Sharp, or Whirlpool.

Now you're ready to go to the store. To find one, we suggest that you look in your newspaper for air conditioners that are on sale and see what else they have in stock. We also recommend that you go to a "superstore" that specializes in selling appliances such as air conditioners (they tend to have the best people on staff to help you… in fact, they're super). And most importantly, don't forget to bring your room dimensions along with you.

Btus and EERs

Once you arrive at the store, the first thing you should look at are the air conditioner's Btus and EERs.

• Watch your Btus. The first thing you're going to come across when you go a/c shopping is the term "Btus." Here's what it means: every air conditioner has a cooling capacity number that ranges from 5,000 to 18,000 Btus. The higher the Btu value, the stronger the air conditioner is. (For the people out there interested in such things, "Btu" stands for "British thermal units.")
  
  "Oh, then I should get an air conditioner with the most Btus possible, right?" NO. Believe it or not, it is possible for an air conditioner to be too powerful (even on its lowest setting). Furthermore, the more Btus an a/c has, the more it costs. Btus are the best indicator of what air conditioner you should buy, so carefully figure out what you're looking for. The smaller the room, the fewer Btus needed. There are two methods to figuring out how many Btus you need:
1. Find the square footage of the room (multiply its length and width). Then check out this chart to see where you fall.
2. Find the square footage of the room, and multiply the answer by 35. That'll get you in the right ballpark.

Here's an example: Let's say your apartment is 12' x 15'. So that's 180 square feet. Using method (1), you know that you should be looking for an air conditioner in the low 6,000 Btus. Using method (2), you are recommended to get an air conditioner with about 6,300 Btus (180 X 35).

In addition, you should follow the following guidelines for proper selection:

• If the room is shaded, reduce the Btus by 10%.
• If the room is very sunny, increase the Btus by 10%.
• If you plan on placing the air conditioning unit in your kitchen, add 4,000 Btus.
• If more than two people will regularly be in the room (e.g., an office), add 600 Btus per person.
• Find the EER number for each unit. "EER" stands for "Energy Efficiency Ratio." Air conditioners with high EERs are good, because they cost less to operate. Unfortunately, they're also more expensive, so you have to find a balance. Air conditioners' EERs usually range from 8.2 to 10.5. So if you're going to have your air conditioner on 24/7 and you're planning on keeping it for a couple of years, then it's worthwhile to get an a/c with a high EER. If you only need an air conditioner to last you through the summer (and you're planning on being at the beach most of the time anyway), get an air conditioner with a low EER.

Here are some other things to think about when purchasing your air conditioner:

• Warranty: Perhaps the most important feature of all, particularly if you have a history of bad luck with electronics. Be sure that your air conditioner comes with at least a one-year warranty that covers labor and parts on the entire unit. This way, if something breaks down, you can return it and get a new one or send it in to be serviced free of charge. Some stores even offer an extended warranty plan (typically covering four to five years instead of just one) for an extra fee. This may be a smart purchase if your electronics always seem to break right after the one-year mark.
• Temperature range: If it spans less than 20° (e.g. 68°-86°F), it may not be sufficient for your needs, particularly if you live in a hot, arid climate.
• Temperature increments: Be sure that the temperature can be incremented in notches of 1°-2°. This allows for greater precision and prevents electricity waste. If you have the cash, get an air conditioner with a digital system (as opposed to a dial), because it allows greater precision.
• Sleep setting/Energy saver switch: Some unit air conditioners have a sleep setting so that at night when you are sleeping, the air conditioner slows the cooling process to a minimum, saving money and energy.
• Slide-out filter: Every unit air conditioner has a filter that must be cleaned. Save yourself an immense hassle and get a slide-out filter air conditioner, not a frame-enclosed one. The slide-out filters are easy to remove and re-install.
• Fan speed settings: How many fan speeds are offered on the unit? The more settings available, the better the energy saving will be (and the more choices you have).
• Installation: Make sure your unit air conditioner comes with installation directions. There's nothing worse than getting the thing home and suddenly realizing you have no idea what you should do with it. If you have any questions about the installation process, definitely ask a store employee for advice before you leave and attempt it yourself. Some air conditioners require that you drill holes into walls or bricks. It would be nice to be aware of such things in advance.