Definitions

When you're surfing the web in search of a new product for your home, certain words come up that are common in the industry, but they may not be so common to you. So, this is our way of making some common terminology that is used by our trade a little more understandable to you!

Ton

In the normal sense of the word, it means 2000 pounds. Well, in the HVAC trades the word TON describes the size or capacity of your air conditioning system. A ton is equivalent to 12,000 BTUs of cooling capacity. So, if you have a 3 ton air conditioner, you have 36,000 BTUs of cooling capacity. BTUs of cooling, are different than BTUs of heating because they are used to describe 2 different forms of energy. Typically heating BTUs are in natural gas or propane. Where as an air conditioner's BTUs are obtained from the capacity of cooling that the refrigerant can produce.

SEER

The ratio of cooling in BTU's to energy consumed in watt-hours. A very common word that is thrown around in HVAC trade that is actually an acronym for " Seasonal Energy Efficiency Ratio", which basically determines how efficient your air conditioner is. For example, the minimum SEER rating of a modern air conditioner is 13, but you can go all the way as high as 21 SEER. If your unit is more than 5 years old it could be as low as 11 SEER, which was the standard before the government raised the minimum to 13.

BTU

An acronym that stands for "British Thermal Unit". A BTU is described as the amount of energy it takes to heat 1 pound of water 1 degree. The standard for rating the heating capacity of a furnace or boiler. The higher the BTUs, the more heat that can be produced. On the other hand, the higher the BTUs, the more fuel that is consumed. That is why you want to make sure your system is sized by a knowledgeable HVAC technician, because you could be burning more or not enough fuel than is required to heat your home.

HVAC

An acronym that means "Heating, Ventilation and Air Conditioning". There is more to your system than just heating and cooling. How well does your system circulate air? Return air sizing and placement is just as important as the duct work that feeds your hot and cold air. If your return air registers aren't sized correctly or they aren't given much thought to placement, you could end up with hot spots in summer and cold spots in the winter. Your furnace or air handler could also be starving for air which could cause your indoor coil to turn to ice or your furnace to shut down because the temperatures in the burner are getting too high. That means your comfort suffers, and so do your energy bills and in some cases even your equipment. It's the returns job to take air from the room to be heated or cooled and at the same time, give the furnace or air handler the proper amount of air needed to function properly and filter the air you're breathing.

Condenser

This is the outdoor part of your system. You know, the one you always have to weed whack around! This is the part of your system that takes the most abuse and normally has to be changed more often than the rest of your system. Coincidentally it is also the most expensive part of your system, which is why it is very important to have a qualified HVAC technician service and clean it every year to ensure it lasts as long as possible. This part is responsible for extracting heat from the refrigerant coming from the house and sending back to the indoor coil to send that ice cold air through your duct work and keep you comfortable during those blistering summer days. The more efficient this part is, the lower your electric bills will be.

Heat Pump

This is pretty much the same as a condenser, but with one big difference, it can HEAT and COOL! Heat pumps work just like a standard condenser in the summer, providing you with nice, cool air to keep you comfortable. In the winter time, they run in reverse to send hot refrigerant to the indoor coil to provide you with nice warm air to keep you comfortable on chilly days. These units have a big drawback here in NJ, they don't work very well when the outdoor temperatures drop below 28 degrees. They tend to freeze up, and then they have to defrost themselves in order to keep heating. During this process, you are left without heat. That is why when we install a heat pump system, we usually install what is known as "back up heat", which is basically an electrical strip that heats up and provides heat while the heat pump is in defrost mode.

Furnace

Furnaces are an integral part of a gas heating system, whether it is LP or natural gas. Most furnaces used to be what was referred to as "80%" furnaces, meaning they only used 80% of the gas that was sprayed into the heat exchanger to heat the air in the duct work, the rest went out to the atmosphere. These types of furnaces typically has metal vent piping and it got very, very hot. Today, the standard are "90%+" furnaces. these models utilize the heat and unburned gas from the vent pipe and circulate it through a "secondary heat exchanger" to make more usable heat, making the furnace more efficient! Today's modern furnaces can go as high as 97% efficiency, meaning that for every $1.00 of gas you put into it, you're getting $.97 worth of heat! Normally these high efficiency furnaces come equipped with variable speed blowers and modulating gas valves that adjust the amount of gas and air needed to heat the space.

Indoor Coil or Evaporator Coil

This part of your system will either be on top of your furnace or underneath of it, depending on the orientation of your feed and return ducts. This is the part that takes refrigerant from the condenser and allows the fan to either blow air over it or pull air through it, to be cooled and sent through the duct work. It is referred to as an Evaporator coil because it will evaporate some of the humidity in the air, making your living space more comfortable. When you have an air handler, this part is built in, where as with furnace, this part be separate and be installed on top or underneath. It is very important that this part is cleaned at least once a year to ensure it is getting proper air flow and there are no obstructions in the coil surface. Another good reason to make sure your filters are changed at least once every 6 months.

Air Handler

This part resembles a furnace in many ways, but is different in many ways as well. If your heating comes from another source such as a hot water baseboard system or electric baseboard system, this part will be used for air conditioning only. A furnace uses gas to provide heat, where as an air handler uses a heat pump and usually some form of back up heat. An air handler has two main parts, a blower with an electric motor, and evaporator coil. There are of course are some other parts, but these are the main components. They are normally considerably cheaper than furnaces because of their simplicity, but are limited to what they can provide. With that said, there are high efficiency models that have multiple electronic boards and variable speed blowers that are capable of being part of a communicating system and are ultra efficient. There is always both sides of the spectrum when it comes to HVAC systems and equipment.