Individuals who do not want to incur the expense of installing central air conditioning but have a need to cool a small space should consider purchasing a window air conditioner unit. This type of air conditioner provides a bit more power, cools the air faster and it is not as noisy as a portable air conditioning unit. These are some things to think about when shopping for a window air conditioner.
Capacity for Cooling
Cooling capacity is measured in British Thermal Units (BTUs) per hour. One BTU is an industry standard that reflects the amount of square footage an appliance can cool under optimum conditions. When you are searching for something to buy, you will notice that many units share similar features but they are rated for different BTUs.
A unit capable of handling more BTUs is more efficient for cooling larger spaces but you need to buy an air cooler that is the proper size for the space. A unit that is too big for the room requires more energy to operate. Here is some valuable information that will help you determine how many BTUs you need.
BTU/hour — Area of the room in square feet
5,000 BTUs — from 100 to 150
6,000 BTUS — from 150 to 250
7,000 BTUs — from 250 to 300
8,000 BTUs — from 300 to 350
9,000 BTUs — from 350 to 400
10,000 BTUs — from 400 to 450
12,000 BTUs — from 450 to 550
14,000 BTUs — from 550 to 700
18,000 BTUs — from 700 to 1,000
24,000 BTUs — from 1,000 to 1,400
Additional things to note are how much sun reaches the room, the number of people in it and whether anything is generating heat within the space. You can reduce the BTU capacity by 10 percent if the room has a lot of shade. You must increase the BTUs by 10 percent for a sunny room. Add 600 BTU per person for rooms where more than two people are occupying the space. If the space is a kitchen or some other room with large appliances that generate heat, the BTU capacity must be increased to 4,000.
Determining Energy Efficiency
United States regulations require all air conditioning manufacturers to reveal the appliance’s EER, or Energy Efficiency Rating. This rating will indicate the unit’s efficiency during normal operation. A unit with a higher EER will cost less to operate. Some units have a separate ENERGY STAR rating. This means they have approval by the government for guaranteed efficiency because more heat transfers to the coils, which requires less energy to compress the unit’s refrigerant. Units with an ENERGY STAR rating exceed government minimum standards by 15%, which makes them less expensive to operate for consumers while at the same time being good for the environment.