Frequently Asked Questions About How Air Conditioners Work

As with most things that people don't have technical knowledge of there is often confusion about how things work and what can be expected from products. The air conditioning industry is no different. This is a compilation of common questions and things that are sometimes misunderstood about how air conditioners work. This is a work in progress so check back occasionally.

How often does my air conditioner have to be recharged?

A common belief is that air conditioners need to have new refrigerant added occasionally. This not true. If refrigerant has to be added to your air conditioner, it means the system has developed a leak and it must be repaired.

There are two reasons for this misunderstanding. The first is that refrigerant is often referred to by technicians as a gas. To most people the word gas means fuel, like you put in your car. These two products are completely different and have no relationship to each other at all.

The second reason for this misunderstanding also lies on the shoulders of air conditioning technicians. In the days before environmental regulations regarding ozone-depleting substances it was not uncommon for some technicians to just add more refrigerant to air conditioners and not repair leaks. Today this is not a common practice and is an indication of poor workmanship.

Refrigerant not Freon

Many people refer to the refrigerant in their air conditioning systems as Freon. Even some air conditioning and refrigeration technicians use this term. Freon is actually a brand name and is so popular that it is often applied to all refrigerants. Other examples of this are Kleenex - facial tissues, Band-Aids - plastic bandages, Scotch Tape - cellophane tape and Velcro - hook and loop fastener.

Some of the common types of refrigerants used in air conditioners today are R-22 and R-410. There are new ones being developed to replace R-22 which is due to be phased out due to its ozone depleting characteristics.

Is Refrigerant Poison - Freon Poisoning

Refrigerant (Freon Gas) is not poison in the sense that you will get sick if you are in a room and a piece of refrigeration or air conditioning equipment leaks and you inhale some. Ventilate the room and have the leak repaired. Service technicians have been exposed to refrigerants for years without ill effects. This only applies to refrigerants that the average person could be exposed to during the course of their daily activities.

However people have died from suffocation when exposed to large doses of refrigerant vapour because it displaces oxygen. As refrigerant vapour fills a room it displaces air. So what happens is you suffocate from lack of oxygen. It takes large amounts of refrigerant and the right conditions for this to happen.

For example, many ships have refrigeration equipment below deck. These can be dangerous situations because the refrigerant would have no place to go. There have been some close calls and some deaths in these situations. The people weren't poisoned they suffocated. With today's safety standards most of these locations are probably equipped with refrigerant leak monitors.

Close Windows When Using Your Air Conditioner

When using your air conditioner it is very important to close all windows. An open window allows unconditioned air to enter the building. This air is warm and has higher moisture content than the conditioned air in the building. Open windows can have a huge effect on an air conditioners ability to operate efficiently.

This can have a huge effect on how air conditioners work. Properly sized air conditioners are designed to cool the space under design conditions. An open window can cause enough extra load on an air conditioner that it will not be able to maintain the desired room temperature. This also increases operating costs because the equipment has to operate for longer periods of time.

What is a BTU?

BTU (British Thermal Unit) - A BTU is the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit. Ton (One Air Conditioning Ton) - A Ton of air conditioning is equivalent to 12000 BTUs/hr or 288000 BTUs/24hrs

What is a Ton of Air Conditioning?

A Ton of air conditioning is equivalent to 12000 BTUs/hr or 288000 BTUs/24 hour period. Manufacturers usually rate their air conditioning equipment in BTUs per hour. So using this information, a 3 ton air conditioner would have a cooling capacity of 36000 BTUs/Hr. Excluding window and portable air conditioners, air conditioner capacities increase by half ton increments

Will Turning The Thermostat To The Lowest Setting Cool The Space Faster?

This applies to both heating and air conditioning. It is commonly believed that adjusting a room thermostat all the way up or down will heat or cool the room faster. This is not how air conditioners work.

When the thermostat is turned to a lower setting the air conditioner starts and works at its designed capacity until the desired thermostat setting is reached. The thermostat only turns the equipment on and off it does not determine how fast the equipment will cool the space. When an air conditioner starts it will work at maximum capacity until the thermostat setting is reached.

There is really nothing to be gained by turning a thermostat below the desired room temperature. You will only have to return and make more adjustments later.