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AC Installation: How To Choose the Right Size AC System for Your Home
At some point, most homeowners will need to decide on the purchase of a new air conditioning system. Most homeowners know very little about this complex building system that affects a family’s health and comfort for many years and even less about the different features available to consumers. The average air conditioner lasts 10 to 15 years, which gives most homeowners little experience with making an AC purchase. However, a few definitions and explanations can help potential buyers get acquainted with the necessary jargon.
An important detail concerning replacing an air conditioner is determining the right size. The terms can be confusing since air conditioners are sold by the ton, but tonnage does not refer to weight. Of course, there are confusing acronyms to cloud the decision. Let’s uncover some basic information about properly sizing an air conditioner.
Basic Definitions
Tonnage. We experience air conditioners pumping cool air into our homes, but the scientific facts are that air conditioners remove heat and deposit it outside. This ability to move heat is measured and expressed with a formula, and the resulting measurement is termed “tons.”
BTUs. You might be more familiar with the scientific term “calorie,” the energy necessary to raise one gram of water one degree Celsius. A British Thermal Unit is the energy necessary to raise one pound of water one degree Fahrenheit, so a BTU is a larger unit of energy than a calorie.
AC Installation Calculations
Simple calculations. The formula for a simple calculation of the air conditioning need multiplies your home’s square footage by a regional number since homes in northern states require less air conditioning energy than in southern states. This number is divided by 12,000 to determine tonnage. A 3,600-square-foot home requires three times as much air conditioning capacity as a 1,200-square-foot home.
Load calculations. A simple calculation will get you a ballpark figure. To properly size your air conditioner, a technician will also take into consideration how many floors, windows, doors, and the quality of insulation in your home. These details may add to the air conditioning need or load.
Quick Review. So far, we have learned that the air conditioner’s function is to move heat outside, that the energy is measured in British Thermal Units, and that the “size” of an air conditioner is measured in tons. Homes in the U.S. generally have air conditioners that range between 1.5 and 4 tons.
Correct Sizing
Technicians go through the trouble of completing a load calculation because installing the correct size air conditioner for a defined space is extremely important.
This one’s too large. An air conditioner system that is too large works very efficiently and reaches the desired temperature very quickly. That sounds good, but another function of an air conditioner is to remove excess moisture from the air and a “short cycle” does not have the time to remove adequate moisture. This can lead to mold or mildew infestations and ruin furniture surfaces. Turning the system on and off frequently also leads to unnecessary wear on electrical components.
This one’s too small. An air conditioner system that is too small works overtime trying to cool the space adequately; during heat waves, it will not keep the space cool enough to provide the desired comfort. The long cycles will wear mechanical parts prematurely.
This one’s just right. A properly sized system will perform all the air conditioning functions efficiently, without undue wear and tear on system components.
SEER and SEER2 Ratings
The Department of Energy protects consumers by testing air conditioner systems during the design phase of development and requiring manufacturers to meet efficiency standards. Air conditioners are rated using Seasonal Energy Efficiency Rating standards. However, the DOE recently updated its research, identifying factors in the field (your home) that were a little different than factors in the laboratory, and now uses SEER2 ratings to distinguish the new rating. Currently, air conditioners sold in Texas must be SEER2 15 or higher.
Have Questions About AC Installation and What Size AC System You Need?
Northwind Air Conditioning and Heat can help you with your AC Installation needs. Contact us and get the help you need.
