Your air conditioning (AC) unit is an important component to your business. You
want to make sure your AC unit is functioning effectively during the hot summer
months. In order to do this, you need to understand at a high level how your system
works. Familiarize yourself with its functionality, different parts, what running
efficiently looks like and sounds like, and any written materials that come with
your unit as reference tools to utilize when problems arise.
Communications Workplace of America, Occupational Safety and Health Department
(CWA) states that more than 500,000 people employed in office environments are
exposed to work-related health hazards each year. One of these common health
problems is indoor office pollution.
It is important that those working within your maintenance department are familiar
with your electrical and mechanical systems throughout your entire facility. They
are the “go to” personnel if something breaks down and are responsible to finding
solutions quickly to get them up and running again.
Not all businesses have a designated maintenance department and/or service
technicians on staff to do this, therefore, it is important to have a few designated
people understand the fundamentals of your system if something does go wrong.

Make sure you know what brand AC unit you have within your establishment. Some
of the most common brands are Trane, Carrier and York.
It is best to recognize the manufacturer and make sure you have all the documents,
warranty papers, past history of service call reports, etc. handy in the event of a
breakdown. This information will help your “in house” maintenance person or the
“service tech” identify the problem much quicker!
You are not expected to be an expert in understanding how AC units function, however, it
is a good idea to learn just how an air conditioning system works to shoot out cool air.
A typical air-conditioning system operates on the principal that when a liquid converts
to a gas it absorbs heat. Air conditioners simply use a liquid (Refrigerant) that
converts to a gas at a very low temperature.
An AC system compresses refrigerant into a high temperature and hi pressure
gas, then condenses the gas into a liquid. The liquid refrigerant passes through a
metering device, such as an expansion valve or an orifice. This metering device
separates the “hi side and lo side” of the refrigerant system. The pressure drop
between the hi & lo side causing the liquid to drop in temperature as it goes
through the cooling (evaporator) coil. The room air passes through the evaporator coil,
absorbing heat from the air flow going through it, therefore charging cool air back
into the room.
In a nut shell, you are not cooling the air; you are removing the heat and expelling
the heat to the outside of the building.
Temperature differentials across the cooling (evaporator) coil should range between
18 to 20 degrees. This is the difference in air temperature of what is going into the
cooling coil and what is being distributed after the coil into the rooms.

• There are basic mechanical components that enable the air conditioning unit
to operate. The first is the compressor, the “heart” of the system, which compresses
the refrigerant into a gas.
• The condenser ejects the heat from the refrigerant
• The metering device which controls the refrigerant flow and pressure drop
• The evaporator, cooling coil, which absorbs the heat and lowers the air temperature
as it passes through it with the help of a blower fan
• After the saturated refrigerant passes though the cooling coil, it picks up heat
and turns back to a low temperature gas to re-enter the compressor and start
the cycle all over again
• Other system parts include: a thermostat, Hi & Lo pressure switches, low ambient
controls, electrical relays, contactors, and fans.

Not only does the cool air provide relief in the summer heat, but it lowers humidity
levels that make you feel comfortable. Yes, your AC unit is also a de-humidifier!

Make sure you keep your manual around in close proximity of your AC unit in case
you need to reference it when a problem occurs.

The best time to get your unit ready for the hot summer months is in the early
spring. You don’t want to wait until the first day of summer to test your AC unit
and then suffer when it won’t function properly. It is best to find the small problems
now, before they lead into larger problems later!

First off, you want to make sure your system works. Just because the heater has
been working all winter doesn’t mean the AC will come on as it should in the
springtime. Before the summer months approach, turn the system on and see if
it’s fully functional. If there is a delay to the unit starting, this may indicate that
you may have a problem. If the unit does start up, begin checking the vents to see
if cool air is coming out of them. Listen for any strange sounds that might be coming
from your system or vents, impending system failure.
During the year, keep your system clean. Many people never think to do this, but
failing to keep filters clean and changed on a regular basis can derail all other efforts
and cost you more on your electric bill. Dirty filters will also lead to poor air flow/
distribution and possibly premature failure of your AC system.
• Replace blower belts as they become stretched and old. Use “cogged” belts
whenever possible
• Lubricate motors & bearings. Keep your condenser and evaporator coils clean
for top efficiency
The best way to care for your system is to be proactive in its care and maintenance.
By planning ahead and addressing maintenance needs on a systematic scheduled
basis, you can save significantly on repairs and virtually eliminate unplanned
There is also no substitute for professional air conditioning maintenance. Spring
is the best time to call your HVAC repair company to check your system and make
sure everything is working correctly. If you wait until the warmest day of the year,
you will often have to wait for service, as most companies will be bogged down
taking care of other clients on a first come first serve basis. This could result in a few
days of suffering from a non-working AC unit; a position that you don’t want to be in.


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