Heating & Air Conditioning Buying Guide

You know you need a new heating and air conditioning system, but you don't know what you need. You've been researching air conditioners online, but you have questions about how all these different systems work. What's the difference between an air conditioner and a heat pump? Is a compressor important?

Don't worry, we can help.

Heating & Air Conditioning Overview

Heating and air conditioning technology can get a little complicated. Let's start with the basics:

  1. Air Conditioners cool and dehumidify.
  2. Heat Pumps cool, dehumidify, and also heat.
  3. Furnaces heat via natural gas, propane, oil, and many other natural fuel options, like wood.
  4. Electric Heaters provide radiant heat using electricity.


Heating & Air Conditioning Systems

Central Air Conditioner Split Systems

Have you been in a typical residential home in the United States? Then you've almost certainly seen a central air conditioner split system. Basically, a central air conditioner split system consists of interior and exterior components connected via communicating wires and refrigerant lines. They are used mainly for cooling, but electric resistance heat strips can be added to provide minor heating as well.

Central Heat Pump Split Systems

A central heat pump split system is much like an air conditioner split system in that it provides a method of cooling your home.  Unlike an air conditioner split system, a heat pump also provides cost effective heat through the use of a reversing valve.  A reversing valve works by reversing the flow of refrigerant, so rather than moving the heat from inside to outside, it moves the heat from outside to inside.

Central Air Conditioner & Gas Split Systems

The 'air conditioner & gas' moniker refers to a package or central split system installation that uses an electric air conditioner to cool and a gas furnace to heat. These are a great option for homeowners who want cooling, but also need powerful heating capacity to make it through winter, especially in places where temperatures can often reach or fall below the single digits.

Central Heat Pump & Gas Split Systems

To maximize heating efficiency, a central heat pump & gas split system (oftentimes referred to as a dual fuel or hybrid system) is not a bad way to go. These air conditioning systems combine an energy efficient heat pump and a gas furnace, hopefully one with a high AFUE, to provide all-year air comfort. The heat pump offers both cooling & primary heating, while the gas furnace assumes the role of a secondary or backup heating source when extremely cold winter weather hits.

Package Units

In terms of installation, package units are one of the simplest heating & air conditioning systems available. Everything needed to provide heating and/or cooling is self-contained inside one single cabinet or 'package'. Place the package unit on your roof or a slab outside your home, attach the ductwork, connect the wiring & fuel line (if applicable), and it's ready to go.  Package units can be obtained in any of the same configurations as the central split systems mentioned above.

Space Heaters & Portable Air Conditioners

Space heating and portable air conditioning units are self-explanatory. If you need temporary heating and cooling in a space, a portable air conditioner or space heater is a great way to go. To make them portable, these units compromise on efficiency, so don't plan to rely on them long-term.

Ductless Split Systems

Central heating and air conditioning systems use an air duct network to distribute conditioned air throughout a building. Ducts are effective, but not always an option. In these instances, ductless air conditioner or heat pump split systems are a reliable, and increasingly efficient, alternative.  Very popular applications are garages, workshops, grow rooms, & server rooms.

PTAC Units (Hotel Style)

Package terminal air conditioner (PTAC) systems are commonly found in hotels, apartments, hospitals, and other buildings that need for individualized air control in multiple, relatively small spaces. PTAC units are simple, compact, and effective. Which is good, since that's the whole point of the design.  These units provide both heating and cooling.


Common Heating & Air Conditioning Components


In an air conditioner or a heat pump, a compressor is the system's beating heart. It pushes the refrigerant through the coils to cool or heat, depending on the setup. Basically, every good air conditioner or heat pump will have a good compressor.

Condenser Coil

Every air conditioner uses a condenser coil as part of their normal operating cycle. It's the job of the condenser coil to expel the heat gathered from inside. Typically, this coil is housed in the same cabinet as the compressor.

Evaporator Coil

Often part of an air handling unit or electric furnace, an evaporator coil is the part of the air conditioner that absorbs interior heat. Because it's absorbing the heat, the air leaving the evaporator is cold. A nearby fan is responsible for blowing that air, usually into ductwork, to cool your home.


Heating & air conditioning units need fans. Without fans, air doesn't move, so a good fan is kind of a big deal. If you find an air conditioner, heat pump, or furnace that doesn't come with a fan or blower, you shouldn't buy it, unless your looking for simple radiant floor heating or space heater options.


If the compressor is an air conditioner's heart, then refrigerant is the blood. Refrigerant flows through the coils moving heat around. Without refrigerant, the foundation of modern heating & air conditioning would not exist. The current refrigerant du jour is R-410A.


Modern heating and air conditioning is great. Being able to tell your system what temperature you want your home is even better. A thermostat lets you do just that. We recommend them. Technically, you could operate a system without a thermostat, but that would require more effort than we're willing to give.


To heat or cool a large building with one heating and air conditioning unit requires ductwork. An air handling unit or blower can use the ducts to move conditioned air to every corner of the building. Strictly speaking, air ducts are not required for large-scale cooling or heating applications, but it makes them much, much more efficient.

Heat Exchanger

Every furnace has a heat exchanger it uses to heat the air. Without the heat exchanger, the heat the furnace creates through the combustion process could not be distributed by the blower fan. Typically speaking, the better the heat exchanger, the better the furnace.


On a furnace, the ignitor is the device that ignites the burner used in the combustion heating process. Older furnaces use pilot lights as the ignitor, but modern models tend to use hot surface ignitors.

Air Filters

Your heating & air conditioning system pulls air in, heats or cools it, then blows it into your home to heat or cool your home. When it pulls in dirty air, some of that dirt sticks around. The dirtier the inside of your heating and air conditioning system, the worse the efficiency. Use a good filter to clean the air going into your system.

Also remember to change your air filter regularly.  A clogged air filter causes your heating & air conditioning system to work harder; reducing it's lifespan.  It can also cause your compressor to freeze over, shutting your system down until it's thawed, and blow your capacitor.

Still Have Questions?

Heating and air conditioning equipment has a lot of moving parts, and this buying guide by no means covers all of them. If you still have questions, we would love to answer them. Please reach out via chat, email, or with a quick phone call.

4 comments (view/add)
  • Matt
    Posted on 6/25/2018

    I have a 24’x 24’ room with 15’ vaulted cowling. What’s the best product to heat and cool it imdevidualy, as it is not connected to the ductwork of the main house

  • Kyle
    Kyle from Ingrams
    Posted on 6/26/2018

    A ductless mini-split is a great option for that. You could look at a conventional option or something like the MRCOOL DIY (http://bit.ly/2I8NwAu).

  • Henry Wattenbarger
    Henry Wattenbarger
    Posted on 6/29/2018

    What is the typical ratio for BTU---per ft square for a Ductless system---thanks Henry

  • Kyle
    Kyle from Ingrams
    Posted on 7/2/2018

    A ductless system would not measure heating or cooling BTUs any differently from a conventional system. A good rule of thumb would be around 6k BTUs per 250 sq ft.

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