Atlas AC Repair, LLC

Get the basics about central air conditioning systems so you can make the best selection for your home.

HVAC basics

Heating and Air Conditioning Basics

How do I find the tonnage of my AC Unit?


The easiest place to figure out your AC tonnage is on the AC unit itself.  Go outside to the condensing unit, find the data tag which is usually to the side and look at the model number.  Within the string of letters and numbers you’ll find an even two-digit number ranging from 18 to 60.  Divide the number by 12 (represents 12,000 BTU/HR or one ton of cooing capacity) to calculate your AC unit’s tonnage.

Or below is an easy guide that does the calculations for you:

18 = 1.5 tons
24 = 2 tons
30 = 2.5 tons
36 = 3 tons
42 = 3.5 tons
48 = 4 tons
60 = 5 tons


What is a heat load calculation?

Heat load describes the quantity of cooling or heating required for a desirable in-home temperature.  The Heat Load Calculation takes the square footage of your home with the ceiling height, multiplied by the difference in temperature desired and the temperature outside, times a multiplier that represents the target building as a sealed structure (.135).  A Heat Load calculation is always a must to be sure the right sized tonnage is selected for the square footage of the home to keep it the right temperature on the hottest or coldest days of the year.

Why is a heat load calculation necessary, even if you already know the tonnage of your system?

A heat load calculation is necessary because we’ve seen too many times where a contractor will undersell a system, selecting too low of a tonnage and it burns up the system since it’s continually overworked.  Atlas AC only install AC Systems that match the square footage of your home so it can run as efficiently as possible for many years.


What is a SEER?

SEER stands for Seasonal Energy Efficiency Ratio.  This is the ratio of the cooling output of an air conditioner over a typical cooling season, divided by the energy it uses in Watt-Hours.  It may also be called a Seasonal Energy Efficiency Rating.  A SEER ratio is calculated over an entire cooling season using a constant indoor temperature and a variety of outdoor temperatures ranging from 60 degrees to 100 plus to simulate a typical season.  Also, keep in mind that SEER ratio is a maximum efficiency rating, like the miles per gallon for your car.  Say your car gets 32 miles per gallon on the highway but if you’re stuck in traffic it’s a lot less efficient.  The same goes for your air conditioner.  If your SEER ratio is 21, that’s the maximum efficiency and it could be lower depending on conditions.

What SEER should you select for your home?

If you’re looking for a system to just get by on for a few years the 14 SEER is the lowest SEER you can selected as mandated by the government.  If you plan on staying in your home for many years to come a 15+ SEER is the way to go for an Energy Efficient, long lasting system.


Whether your home has a furnace or an air handler depends on the kind of heating system it has.  If you heat your home with gas, liquid propane or heating oil, you most likely have a Furnace.  If you have an electric heat pump, you probably have only an Air Handler.


Your Air Handler or Furnace is typically found in an attic or closet.  Most of the doors or entrance openings to the Air Handler or Furnace are large enough to fit them through but in some in some cases they were sheet rocked into the homes, making it a little harder for repairs or to replace.


Honeywell Non-Programmable:

For simplicity and comfort control, look to Honeywell Home non-programmable thermostats.  From the classic circular dial model to easy-to-use soft-touch buttons and backlit displays, the non-programmable thermostats allow you to easily set your preferred temperature with the touch of your hand.

Honeywell Digital:
Take control of your home comfort and save on energy costs with a programmable thermostat.

The Nest Learning Thermostat is the first thermostat to get ENERGY STAR certified. It learns what temperature you like and builds a schedule around yours.


What is a Condenser Pad?

A condenser pad goes at the base of your Air Conditioner Condenser.  The condenser pad is like the foundation of the AC unit and it’s very important for it to be level and secure.  The condenser pad also raises the air conditioner condenser off the ground to protect it from the moisture of the yard, pests and away from surrounding debris or vegetation.  The stability of the condenser pad keeps the AC unit securely in place so that it can function optimally, even with the vibrations of the running unit.  A broken for falling apart condenser pad can create an unlevel and unstable base for your AC unit, potentially creating issues and shortening the lifespan of the system.  A properly fitted air conditioner pad provides a good foundation and helps ensure a long life for your AC System.

When should you replace your condenser pad?

If your condenser pad is cracked, sagging or sinking, it must be replaced.  If your condenser pad is over 10 years old but in ok condition we still recommend that it be replaced so the replacement AC condenser is installed on a strong foundation.


What is a line set?

A line set is simply a pair of copper tubes that connects a condenser to an evaporator.  Inside the insulated pipe there are two sets of lines, the smaller tube is the liquid or discharge line and carries dense liquid refrigerant to the evaporator where it can absorb heat.  The larger tube, called the suction line, carries lighter gaseous refrigerant back to the condenser where the heat can be rejected.  The refrigerant and vapor in the lines is continually recirculated in a loop to provide either heating or cooling depending on the direction of the flow.  If your system has a heat pump feature, the flow is simply reversed to provide heating.

What is a line set cover and do I need one?

The line set cover goes over the line set pipe to protect it.

Is it a must-have?  No, but if a large portion of your line set is exposed to the elements additional protection is recommended.


Surge protectors

A surge protector prevents electrical spikes such as lightning strikes, electrical shortages, or power outages from damaging valuable electronics and appliances in your home.

Should I get an AC surge protector on my system?
Most people know their TVs, computers or other electronics should have surge protectors connected, however, many people don’t protect one of the largest and most expensive electronic appliances in their home, their heating and cooling system.  Air conditioning repairs from damage caused by lightning are usually not covered by the warranty of the HVAC system.  Fortunately, many home insurance policies can cover damage caused by lightning, however, the burden is on the homeowner to prove the damage was caused by lightning and not from any other source.

Smoke & carbon monoxide detectors

Many forums state you should have a CO detector and smoke alarm in each bedroom or other sleeping areas for safety.  CO is a poisonous gas that’s colorless and odorless and if it surpasses 70 ppm for long periods of time can cause severe health effects.  Having these installed throughout your home can add another layer of safety for you and your family.


What is a Duct Disinfectant and do I need it for my home?

Atlas recommends your ducts get disinfected periodically.  Running the Bio-Fogger throughout your AC system helps control bacteria growth and helps ensure optimum air quality.

Learn More

What does the UV Light do and do I need one for my home?

The UV Light is installed inside your furnace or air handler, working to inhibit growth of microbes such as mold and bacteria 24/7.

Learn More


What is a Media Filter?

A media air cleaner is a metal cabinet that houses a media air filter.  It’s placed in the return air duct of the forced air system before the furnace or air handler.  As air passes through the HVAC System the media air filter traps airborne particles within the filter so they can’t enter into the home.

Do I need a Media Filter for my home?

Most homes have a standard return air filter made from loosely woven spun glass fibers designed to keep the ductwork and furnace or air handler clean but unfortunately it doesn’t improve the indoor air quality.  It takes a media filter with its deep pleated design to remove dust, pollen, pet dander and other particles from your home.  If you struggle with allergies or just want cleaner air for your home it’s worth getting a media filter installed.


The 3, 5 and 10 year additional warranty options covers the labor for any needed repairs.  Just give us a call and we’ll take care of it at no additional charge.