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.

40 comments (view/add)
  • Vince magdirila
    Vince magdirila
    Posted on 7/14/2022

    Which one is better rheem or Goodman central heating and air conditioning system
    What is the advantage of one another

  • Rebekah Muller
    Rebekah Muller from Ingrams
    Posted on 8/12/2022

    It really depends on your specific needs. While there are many similarities, one benefit that Goodman may have over Rheem is that there are more contractors who specialize in them. Otherwise, it depends on your personal needs and wants.

  • M. Barac
    M. Barac
    Posted on 11/16/2021

    410A gas in being phased out. Does your system run on R42?
    My condo 1500 sw ft has two floors
    Do I need two units and an air handler?

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 11/17/2021

    R-410A will not be phased out for many years yet. It likely won't start being phased out until the 2030s at the earliest. A condo with two floors could be well served by a dual-zone unit.

  • Rob
    Posted on 6/21/2021

    I live in Michigan and built an insulated workroom in my pole barn that is roughly 400 sq/ft. would a Mini-Split system work to heat and cool it? Worried it may get too cold for the heat pump to work.

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 6/28/2021

    A mini-split could definitely work. Given your state's climate, you should definitely look into a mini-split with a high performance heat function like the MRCOOL or Mitsubishi Hyper Heat units.

  • Gene Gilreath
    Gene Gilreath
    Posted on 4/28/2021

    I live in western n.c i have a 1800sq ranch home.what size heat pump would you recommend. Natural gas is available.

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 4/29/2021

    Most likely you would need a 3 ton system. That would be my best guess anyway.

  • Frank
    Posted on 11/14/2020

    I have a rental unit the central AC died. It has ductwork in the attic. Would a package unit work if I put the return duct under the house and go back to the unit with a supply I will separate return and supply into the old unit inside

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 11/16/2020

    In general terms, any house could use a split system or a package unit if the ductwork were configured in the right way. Provided the ductwork in your rental can be reconfigured properly to work with a package unit, it should work.

  • AC
    Posted on 8/14/2020

    1.Need a 5 ton and a two 3 ton units for a new construction house and detached garage. Size restriction not to exceed2’x2’. What do you suggest.?
    2.Is American Standard available.
    3. What are the maximum / longest, line set lengths in feet?

  • Kyle
    Kyle from Ingrams
    Posted on 8/14/2020

    1. 2'x 2' could be hard to accommodate.
    2. We do not carry American Standard. But we have plenty of other comparable products.
    3. The longest individual line set typically available is 50'. However, those can be extended in the field.

    Give us a call at 270-575-9595, and we will do our best to find the right product for your job.

  • David Lombardi
    David Lombardi
    Posted on 6/9/2020

    Can we change a condenser that has r 22 freon to a new system that uses 410 freon.
    And still use the same air handler.
    The unit is a 5 ton goodman about 12 years old.

  • Kyle
    Kyle from Ingrams
    Posted on 6/10/2020

    If the condenser manufacturer, I'm assuming Goodman, lists the air handler as being compatible with your new condenser and R410A, then it would work. If it's not a Goodman condenser then even if you could get it to work with the air handler, it would likely void the warranty.

  • Robert Ferguson
    Robert Ferguson
    Posted on 5/26/2020

    How close to the ceiling can the interior unit be mounted

  • Kyle
    Kyle from Ingrams
    Posted on 5/27/2020

    I assume you're asking about a mini-split air handler. The standard answer is refer to whatever the manufacturer requires in their installation manual. Typically, at least 6 inches or more.

    Posted on 11/26/2019

    Looking to put gas heating and cooling in a 3300 square foot house three floors what size and unit would you suggest? House is being renovated so options are open at this point.

  • Kyle
    Kyle from Ingrams
    Posted on 11/27/2019

    For gas heating, you can't beat a good furnace. The obvious solution would be a traditional central split system heating and air conditioning system. Give us a call at 270-575-9595, and we'll help you figure out what you need.

  • Doug Bathurst
    Doug Bathurst
    Posted on 11/12/2019

    I’ve installed several duct style split systems in the past. Wouldn’t do it myself anymore The ductless mini splits are an interesting thought. Much more efficient not using ducts, especially in attics I’m thinking. However in most cases the refrigerant lines would still run through the attic I suppose, and it sounds like more labor to run the lines. Then again, no labor or material for ductwork. Sounds appealing, and more efficient. I have an 80’s 1500 square foot home, with full basement. Does a ductless system make sense in this scenario? Thank you

  • Kyle
    Kyle from Ingrams
    Posted on 11/13/2019

    A ductless option certainly can work for that sort of application. I would recommend you take a look at multi-zone systems like the Olympus. https://iwae.com/shop/heating-air-conditioning/full-systems/ductless-split-systems/?series=521

  • joe
    Posted on 8/4/2019

    do we run separate control wire and copper tube to each evaporator coil?

  • Steven
    Steven from Ingrams
    Posted on 8/5/2019

    Control wire is supposed to be connected between the condenser and your air handler or gas furnace. Copper refrigerant lines are supposed to be connected between the condenser and the evaporator coil. When you say "each" evaporator coil, I'm unsure what you are referencing. There is only one evaporator coil in a split system. If your speaking in regards to multi-zone ductless mini-splits, then yes, separate control wire and refrigerant lines are run between the condenser and each air handler.

  • Hap Welty
    Hap Welty
    Posted on 4/13/2019

    I live in Charlotte NC where we have mild winters and extreme summers. I have a gas furnace and a stand alone AC unit with duct work throughout the house. Would it make sense for me to only use the hotel style units in 2-3 rooms to give me smart energy consumption? - using only heat or air where we need it - not the entire house? thanks Hap

  • Kyle
    Kyle from Ingrams
    Posted on 4/15/2019

    It could. Though you would want to run the air conditioner some basic amount in those unused areas in summer to prevent damage from extreme humidity build-up.

  • LJP
    Posted on 3/23/2019

    Do you have a system that will work well in a van or small RV?\ and can run on solar?

  • Kyle
    Kyle from Ingrams
    Posted on 3/25/2019

    A ductless mini-split could be a good fit for a van or small RV. The Advantage 9k would be the best thing we have for that. https://iwae.com/shop/9k-btu-17-seer-mrcool-advantage-ductless-heat-pump-condenser-ha11007.html

  • Karri
    Posted on 3/4/2019

    Our main concern is heating. We have heard that heat pumps do not work properly in extremely cold temperatures and we have winters with temperatures often far below zero. What is the lowest temperature that MRCOOL heats well in?

  • Kyle
    Kyle from Ingrams
    Posted on 3/5/2019

    That depends on the MRCOOL unit. For cold weather, the MRCOOL Hyper Heat would be the most effective. It will heat down to 5 degrees. That works well enough for most people. But if you often experience below zero temperatures, a gas furnace is the most effective tool to maintain a comfortable interior temperature.

  • Clifford Wiley
    Clifford Wiley
    Posted on 8/25/2018

    Our fan outside quit working. The unit works but not the fan. What propels the fan to keep running? Do I need a new ;unit or a new condenser ?


  • Kyle
    Kyle from Ingrams
    Posted on 8/27/2018

    The fan in the outside condenser has its own motor. If it is not working, but the compressor is fine you may just need a new fan motor. Which would be a lot cheaper to replace than an entire condenser. You should arrange a service call to evaluate the unit.

  • Joseph R Racila
    Joseph R Racila
    Posted on 8/20/2018

    How big of a system do I need how many guess tons? I have 1,000 square feet upstairs and a cool concrete basement downs stairs. Upstairs each room has a vent except living room has 2 vents. Down stairs has 4 vents... upstairs has total 6 vents. Air return upstairs has 3 return lines, Downstairs has 2 return lines...

  • Kyle
    Kyle from Ingrams
    Posted on 8/21/2018

    System size is best determined by a Manual J heat load calculation. It would be very hard to give you an accurate assessment just from the information presented. Give us a call at 800-360-1569 and we will help you figure it out.

  • Joe Vignona
    Joe Vignona
    Posted on 8/8/2018

    I have a oil hot water boiler to hot water coil heat blower heat/ac condenser. 2 zone AC system in one zone 15-18 yrs old condenser on last leg can I change to a heat pump I got solar system for house
    What would u recommend if I just changed the AC system 1.5 ton I live in NY

  • Kyle
    Kyle from Ingrams
    Posted on 8/9/2018

    Yes, you could change to a heat pump. If you are looking for ductless, we would recommend MRCOOL or Mitsubishi. For a conventional system, we would recommend Goodman. Give us a call at 800-360-1569, and we will answer all your questions to make sure you get the right system for your home.

  • IZZY
    Posted on 7/29/2018


  • Steven
    Steven from Ingrams
    Posted on 7/30/2018

    Most cannot, however some furnaces are designed to allow for conversion. It would specify such in the manufacturer specification manual. Our website also specifies whether it's convertible within the product specifications tab on each product page.

  • 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.

  • 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).

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