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Fixr.com Essential Guide to HVAC

Cristina Miguelez

Published on January 21, 2022


Fixr.com Essential Guide to HVAC

This guide aims to make an in-depth but at the same time very visual comparison of the most popular systems to better understand the HVAC options in the market.

To provide you with the most accurate and up-to-date information, we consult a number of sources when producing each article, including licensed contractors and industry experts.

Read about our editorial process here. Want to use our cost data? Click here.

HVAC systems keep your home comfortable year-round. HVAC is a broad term that encompasses all types of heating, cooling, and ventilation, such as furnaces, air conditioners, and attic vents.

With the numerous options of HVAC systems, there is a broad range of associated costs. A simple baseboard heater has a very different price point than a gas furnace, and how large your system is and where it is installed can also impact the final price. That is why choosing the right HVAC system for your home can be a complicated process. Cost, size, energy efficiency, projected energy usage, and climate zone all need to be considered to help you find the right system. 

This guide aims to make an in-depth but at the same time very visual comparison of the most popular systems so that homeowners can better understand the HVAC options in the market. We go through the pros and cons of each system, when it is best to use one over the other, how they stack against each other in terms of energy efficiency and cost, as well as size considerations and other expert recommendations. 

Home Heating Systems Comparison

Homeowners face many options when determining which heating system type to use. Factors like your house location, energy needs, and personal priorities, such as preferring renewable energy or cleaner fuels, are key when determining which system is best suited for you.

All heating systems have three components. The first one is the heat source, which is the system that “generates” the heat (i.e., boiler), the second is the distribution system, which moves the heat through your home (i.e., radiator), and the third one is the control system, which regulates the amount of heat distributed (thermostat). In this comparison, we will focus on the heat sources.

The most used heat sources for heating systems are boilers, furnaces, and heat pumps. Below we explain how each system works, along with notes about the most common heat-distribution systems used for each:


Boilers heat water to provide hot water or steam, which is then circulated throughout your home with different types of radiators or in-floor radiant heating. Because they use water, a minimum temperature is required to prevent the pipes from freezing. They can operate with gas, propane, electricity, or oil. Not as common as the other boilers, wood boilers could be an interesting option if you live in a rural area and have access to wood.


Furnaces heat air, and with a blower motor and a network of ducts and vents, the air is circulated throughout your home. Because furnaces use forced air systems as heat distributors, they are frequently paired with central air conditioning to cool your home using the same duct network. Furnaces can operate with natural gas, propane, electricity, and oil.

Heat pumps

Heat pumps can take heat from the air (air source heat pumps) or ground (geothermal heat pump) and transfer that heat into your home. Unlike boilers and furnaces, heat pumps can also be used to cool your home. When running in reverse, they take heat from your home and deposit it back into the air or ground outside. All heat pumps use electricity, and they distribute heat through ducts and vents, like furnaces, but they are also compatible with radiant heating. 

To make the decision between these three easier, we created a graphic that shows you how each system and fuel type stacks up against the others in terms of: efficiency, environmental impact, maintenance needs, cost to install, and cost to run. This lets you see at a glance how the attributes compare, allowing you to determine which one may be a better fit for your needs, budget, and priorities.

Each variable is ranked on a scale of 1 to 5, with 1 being the lowest or worst score a variable can receive and 5 being the highest or best. The Fixr.com team calculated these variables taking into consideration Fixr.com cost guides and several reference sources. The “Environmentally - friendly” factor depends greatly on the fuel the system uses. For systems whose main energy source is electricity, we assigned it a 2. This is because the main sources of electricity in the U.S. come from fossil fuels. However, if your source of electricity is greener, such as you have solar panels installed, this factor will vary. Also, we put together gas and propane boilers because many units can run both with gas and propane. 

As you see, each system has pros and cons. Some are extremely efficient and cost little to install while others have a big impact on the environment or are costly to run. This is the case with most electric units, except for heat pumps, which are not recommended for too cold or too warm climates. Like propane and gas systems, others receive moderate-to-high marks in every category, making it a solid middle-of-the-road choice. There are also less frequently used systems, such as outdoor wood boilers and geothermal heating, which are the costliest to install despite the benefits.

Using this graphic, you can better determine the factors that will directly impact you, what you care the most about, and then see how your preferred system stacks up in those areas and against other systems.

Heating Systems Pros and Cons

In the section below, we break down the pros and cons of each system and provide recommendations on when best to use them. Click on the different buttons to learn more about each system and fuel.

Heating Systems Cost Comparison

The following whole-house heating system comparisons allow you to see how the various systems, with their different fuel types, rank against one another regarding installation and system costs.

There are also possible additional costs associated with these projects that are sometimes included in the price. For example, most installers remove and dispose of an old unit at no additional cost, but others charge a fee of up to $200 in addition to other labor costs. While permits are not required in all areas, some states and municipalities require them. In this case, you may pay an additional $100 in permitting fees.

About the costs described below:

Note that the installation cost described below accounts for installing or replacing a newer version of the same system type, such as replacing a gas boiler with a newer gas boiler. When replacing an electric furnace with a gas boiler, there may be additional costs to include. Also note that the final cost depends on several factors, such as the unit size, efficiency, location, whether you are upgrading to a high-efficiency system and need a drain installed, and if you need to retrofit spaces in your heating system to incorporate the new system.

Boiler Cost Comparison

Here are the cost comparisons to replace a gas, electric, oil, propane, or wood boiler with a new one. In the case of boilers, the cost to replace them versus the cost to install them for the first time is the same. As you see, propane and gas boilers have identical costs. This is because the same system can often run on both, allowing flexibility in fuel types regardless of whether you live in an area with access to natural gas. However, although they have identical installation costs, the cost to run and other initial costs, such as installing a gas pipe for gas units or installing a propane tank for propane ones, vary. 

Of the various options, outdoor wood boilers cost the most on average to purchase and install, while electric boilers cost the least for both. 

Boilers can be great options when there is no ductwork installed. Also, the type of heat they produce (radiant heating) is often considered the most comfortable one. Boilers are often paired with split air conditioning units that do not require ductwork.

Furnace Cost Comparison

This graphic lists the costs to replace a furnace fueled by gas, electricity, oil, and propane. The cost to replace a furnace is slightly lower than installing it for the first time and varies greatly when converting a different system to a furnace. In most cases, when you need to replace your furnace, your ducts might also need repairs or replacement, as well as extra modifications if you are adding a high-efficiency unit. So, the costs above range from no modifications to moderate ones. 

Furnaces are often paired with air conditioners because, as forced air systems, they use the same ductwork to both cool and heat your home. Some units incorporate both the air conditioner and furnace, often referred to as HVAC Packaged Units or Central AC Packaged units.

Heat Pump Cost Comparison

Again, the graphic shows the average costs to replace or install a new heat pump to heat the entire house. As you see, geothermal heat pumps tend to be the most expensive, and the labor cost represents a much higher percentage of the total cost than in the other systems. This is because this installation is very labor-intensive, and a lot of equipment is needed to lay the pipes and excavate. 

Air source heat pumps (central/ducted) come in second place regarding price. However, these systems are not recommended for very cold climates. This is why dual fuel systems, also called hybrid heat pumps, are a better solution for northern areas. These systems work in combination with a high-efficiency gas furnace. So although around 80% of the time you would use the heat pump to heat your home, which has a low energy cost, when the temperature drops to 5º F, you could use the furnace. All units use at least some electricity to move the heat.

Home Cooling Systems Comparison

Cooling systems have the same issues as other HVAC systems, and again, homeowners face multiple options to choose from. 

The most-used cooling systems are air conditioners, heat pumps, and evaporative coolers. Almost all these systems are available to cool an entire house or work as a supplementary cooling system that cools only one or some rooms. Below we explain how each system works:

Heat Pumps

As explained in the heating section, heat pumps can work to cool or heat your home. When working to cool it, they take heat from the interior of the house and transfer it to the air (air source heat pumps) or ground (geothermal heat pump). These systems use electricity and can work to cool your entire house through vents and ducts or just one room, like mini-split systems that are great options for home additions or small homes in moderate climates.

Air Conditioning Systems

Almost all American homes have an air conditioning unit at home. These systems employ the same principles as a refrigerator. They remove the heat by passing the air over refrigerated coils and condense it to remove extra moisture. There are many types of air conditioning systems. Some, such as central air conditioning units, can cool an entire home, while others like window AC units, also called room air conditioners, are more suitable to cool only one or some rooms in the house.

Evaporative coolers

Evaporative coolers, also known as swamp coolers, work by adding moisture to the air via a water source. They take outside air and pass it over a source of water, where the water evaporates into the air and cools it. Although they are only recommended for dry areas, they offer an affordable and energy-efficient alternative to air conditioners

To help you decide between these options, we ranked these systems using four variables: energy efficiency, maintenance, cost to install, and cost to run. As with heating systems, each variable is ranked on a scale of 1 to 5, with 1 being the lowest and worst score an attribute can have and 5 being the best and highest. They are grouped in two rows: the first row for whole-house cooling systems and the second for complementary systems.

Each cooling system has pros and cons. Some, like all heat pumps, earn great scores in most aspects. But others like evaporative coolers have good scores only in some areas. Most air conditioners have low scores. However, only air conditioners are suitable for any climate, with heat pumps recommended for mild ones and evaporative coolers only for dry ones.

Cooling Systems Pros and Cons

In the sections below, we break down the pros and cons of each system, along with recommendations on when it is best to use them. Click on the different buttons below to learn more about each system.

Cooling Systems Cost Comparison

The following comparisons allow you to see how the different cooling systems rank in terms of installation and system costs.

We grouped the cooling systems into two graphics: systems meant to cool an entire house and complementary cooling systems, more suited to cooling only certain rooms or zones.

Full House Cooling Systems Cost Comparison

In the graphic, you see the costs to install each cooling system, all meant to cool an entire house. The costliest one is the geothermal system, with a big difference compared to the rest. They require a lot of equipment for the installation, raising the total costs. 

In second place, there are air source heat pumps. As heat pumps also work as heating systems, they are not often paired with other systems. However, in very cold climates, dual fuel heat pumps or hybrid heat pumps are often used. They include a gas furnace that works when the temperature is too low. 

Central air conditioners are often paired with furnaces to provide heat and cooling in homes because they use the same ducts to distribute air. However, some central AC systems come equipped with electric heating coils to provide your home with warm air during the winter. Others, such as packaged systems, often come with the furnace already incorporated in the unit. 

Evaporative coolers are the cheapest option. Although they are great options for very dry climates, they are not as popular as other cooling systems.

Complementary Cooling Systems Cost Comparison

This graphic shows the average cost to install complementary cooling systems. Mini-split air conditioners or heat pumps can also be used to cool an entire home. But for the comparison, the costs shown correspond to installed single-zone units, such as for a home addition, small houses, open spaces, or homes that do not need cooling regularly. Window air conditioners are used to cool individual rooms only, being the cheapest option. 

In general, none require a very invasive installation, and the decision between them depends on your budget, climate (heat pumps are not recommended in too hot climates), and your cooling needs.

Understanding Energy Use and Efficiency

When you need to decide between several HVAC systems, there are important factors to keep in mind, and one of them is energy efficiency. To measure energy efficiency, several indicators help you identify more efficient units.

Heating systems:

Furnaces and boilers: AFUE stands for Annual Fuel Utilization Efficiency. It applies to furnaces and boilers and is the ratio of the system’s heat output in a year compared to the total annual fossil fuel energy consumed. This metric is shown as a percentage. Older, low-efficiency AFUE ranges from 56% to 70%, while high-efficiency units range from 90% to 98.5% AFUE. This also varies depending on the fuel your system uses.

Heat pumps: The heating efficiency of heat pumps is measured using the Heating Season Performance Factor (HSPF) or Coefficient of Performance (COP), depending on the heat pump type. HSPF is the total heat provided over a heating season divided by the total electricity consumed and ranges from 6.8 to 10. COP is the heat provided divided by the amount of energy input and ranges from 2 to 4.

Cooling systems:

Air conditioners and heat pumps: Air conditioner and heat pump (in cooling mode) efficiency is measured by Seasonal Energy Efficiency Rating (SEER). The higher the SEER rating, the more efficient the unit and the cheaper it will be to operate, translating into lower energy bills. The U.S. Department of Energy rated 13 as the minimum for contemporary systems, with highly efficient units having a SEER rating of 20 to 25. However, you can find old units with a SEER rating of 8 or 10.

HVAC Regulations:

Recent changes to HVAC regulations mean that beginning in 2023, standards and minimums for efficiency will change across the country. This means that SEER will increase by 1 point for all air conditioning units, and EER and SEER2 will also increase. In addition, many states have begun their own regulations, which will begin rolling out in 2023. These changes will directly impact both professionals and customers, resulting in potentially higher upfront costs but better efficiency and lower monthly costs.

Most Requested Energy Star HVAC Systems

ENERGY STAR® is a program of the Environmental Protection Agency (EPA) together with the Department of Energy (DOE), whose goal is to help consumers save money and protect the environment at the same time by acquiring energy-efficient products and practices. The ENERGY STAR label identifies top-performing, cost-effective products, homes, and buildings.

We asked experts which are the most requested Energy Star HVAC appliances, and they claimed that the most requested systems are ductless mini-splits and smart thermostats at 69% and 62%, respectively. Air source heat pumps are also among the most requested at 52%. 

Smart thermostats are also a good choice no matter where you live or which HVAC system you have. They can work in several ways to learn your schedule and whereabouts so that you use less energy overall by only running the HVAC system when you are home.

Small HVAC Units

Many homeowners use small supplemental HVAC units to help heat and cool their homes. They believe this saves money over the installation of a much larger whole-house unit. However, we asked experts to list the appliances they think homeowners most often underestimate in terms of energy-wasting, and we weighed in on how much energy these units actually waste. While they may be less expensive than a larger unit, you may find that for the amount they heat and cool your home, they may be causing much higher bills than you realize.

The biggest issue why this occurs is the efficiency factor (EF) of each unit. Most smaller units have very low EF, while most larger units have minimums of efficiency that they must meet. This means that larger units have an EF of .80 to .98, meaning they convert 80% to 98% of the energy they use into warm or cool air for your home. Smaller units, such as electric or oil space heaters, are much less efficient, meaning they tend to waste more energy than they produce.

HVAC Sizing

A key part of deciding your HVAC unit is choosing the correct size. This is directly related to the climate you live in and the size of the space you need to cool or heat. Every HVAC system is sized using British Thermal Units (BTUs) as its measurement. A BTU is the amount of heat required to raise the temperature of a pound of water by one degree. Generally, the system size will be tied to the home size, although different systems can have different BTU sizes even for the same home size. Cooling systems are often measured in tons.

In general, the colder your climate and the larger your home, the more BTUs you need.

Keep in mind that not all fuel sources are available in all areas. Propane and oil are mostly available only in the Northeast and Midwest. 

At the same time, not all systems are recommended for all climates. For example, electric furnaces are generally only used in zones 1 to 3 because of their inefficiency at heating spaces in cold climates. Air source heat pumps are generally used as supplementary heating in cold climates and may be used as supplementary cooling in hot climates.

How Big Should My Heating System Be to Heat a 2,000 sq.ft. Home

The graphic below shows the number of BTUs needed for each heating system based on climate zones. This is the average number of BTUs required to heat a 2,000 sq.ft. home.

Climate zones move from warmer to colder as the number increases. Notice that the number of BTUs also increases as the climates get colder even though the home size remains the same. Heat pumps are not recommended as the primary heating system for homes in cold climates because they cannot keep up with the demand. However, many people in these zones often use heat pumps as a system to cool their homes in summer and add extra low-cost heat in the winter in the way of a complementary system, often combined with a furnace.

How Big Should My Cooling System Be to Cool a 2,000 sq.ft. Home?

In the same way as heating systems, these are the sizes recommended for systems in each climate to cool a 2,000 sq.ft. home. 

The cooling capacity of heat pumps and air conditioners is measured in tons. As for evaporative coolers, the size is calculated in Cubic Feet per Minute or CFM. 

Heat pumps are not recommended as a primary cooling source in very dry and warm climates, and evaporative coolers are not the best cooling source in humid climates.

Expert Recommendations

What To Consider When Upgrading HVAC Equipment

Apart from the points mentioned above, we asked experts to rank how important they think the following aspects are when choosing HVAC equipment. According to them, the most important considerations are the costs, both the upfront system cost and the ongoing cost of your bills. The initial upfront cost is generally the biggest concern for most people simply because it can be a large outlay at once. Many people want to save on this initial expenditure, while others look at it as an investment in their future energy bills.

Upfront and ongoing costs need to be weighed against one another to find the best system for each household. Some systems cost more upfront but save you long-term. 

However, this does not always make sense because climate can affect how much you actually use and save. For example, if you have to decide between an average unit and the most efficient unit available, purchasing the most efficient one possible will cost more upfront, and only those in very cold or very hot climates will see enough of a difference in their energy bills to make it worthwhile.

The space dimensions and location are also concerns. If you have space for your unit and it is easily accessible, your labor costs could be lower, and you will have the most options for the unit size and shape. However, if your space is limited, this could translate into fewer options for the unit. 

Modifications are also a major factor to consider. When upgrading to an energy-efficient system, you will not only pay more for the system, but you will also pay more for the installation. This is because energy-efficient systems require things like drains and vents, making the installation more difficult and time-consuming.

Finally, the impact of how this system will work with other systems needs to be considered. For example, if you have central air conditioning, the same ducts will be used with a furnace, and both systems will share a thermostat. Boilers may heat your hot water as well as your home. Some new HVAC systems require you to upgrade your thermostat or may work better if you add on a humidifier, filter, or other system that can impact more than just the initial system and setup costs.

Apart from these, experts added additional recommendations:

One of them is to read the warranty of the equipment carefully and understand in which situations the warranty might be invalid, such as having your HVAC installed by an unlicensed contractor in some cases. Federal regulations prohibit handling refrigerants by people who have not been certified. This is why DIY HVAC installations are not recommended at all. Taking care of these installations yourself can end up costing much more than what you would save:

Inexperienced homeowner HVAC installation will almost always result in problems.
Brent Evans, Instructor - HVAC-R Program Manager.
authorship avatar

Experts’ Tips to Lower Utility Bills

Apart from using more energy-efficient HVAC equipment, there are many other ways you can save money on electric bills each month. Combined, they can have a great impact. 

We asked experts which are the most recommended changes, and 90% of them agreed that the most recommended way to save on electric bills is to add insulation to your attic. This helps stop energy loss, making your home more comfortable and energy-efficient. 

The next most recommended (69% of them agreed) is adjusting your thermostat when you are away. This can be done easily with a programmable thermostat, which you can set based on the times you plan on being at home or work. Lower your temperature during the winter, and raise it during the summer when you plan on being gone. Have the system turn on again about an hour before you are due back so that the home is comfortable when you arrive. 

Additional ways to save on an electric bill include installing energy-efficient windows, increasing your insulation on pipes and ducts, and switching to a tankless water heating system.

Smart HVAC

Top Benefits of Smart HVAC Systems

Smart HVAC systems are one way homeowners can get a more energy-efficient home. In fact, the number one reason why most people install a smart system is to save energy. When asked, 97% of experts felt that energy savings was the biggest benefit behind installing a smart HVAC system. This is followed by 60% reporting that the system can adjust to the occupants’ schedules - a big plus in people’s busy lifestyles. 

Other reasons include helping homeowners solve potential problems before they need to call a professional, reminders of when to conduct inspections, and helping homeowners understand the unit’s efficiency to better grasp how much energy their system uses each day.

Biggest Problems of Smart HVAC Systems

Like any system, a smart HVAC system has drawbacks. According to 77% of experts polled, the biggest drawback is finding a technician who can work on them

Smart systems are still relatively new compared to how long other HVAC systems have been in operation. Therefore, many technicians may not be up to date on the latest technologies. This can mean that when you invest in a smart system, you may need to contact the manufacturer or installer each time it needs servicing and pay more for a technician who has undergone the necessary training. 

Other issues mentioned include a potentially poor return on investment, device incompatibilities, and security flaws. Some homes may also need additional modifications, adding to the overall cost. 

Because of the novelty of these systems, it is crucial to check these issues before purchasing and ask all the necessary questions to technicians and installers.


The data shown in this report was collected in two main ways. One was with a multiple-choice question survey completed by experts (HVAC technicians, contractors, and others), listed alphabetically below. The second way was by the Fixr.com team’s research into costs, HVAC systems and sizes, and energy consumption. All sources used are listed below.


Fixr.com Team


11 February 2022

Experts That Participated

Brent Evans
Instructor - HVAC-R Program Manager
Johnston Community College
Larry Stone
AC Technology Program Coordinator
Owensboro Community & Technical College

Edward Montvidas
HVAC Senior Engineer
MMR Consulting
Mitchell Thomas
Trade and Industrial Program Specialist
Oklahoma Department of Career & Technology Education

James Weeks
HVAC Owner
Affordable Air Experts
Senobio Aguilera
HVACR SME Instructor
Chaffey College

Jim Crist
HVAC Division Manager
U.S. Heating and Air
Theresa Spurling-Wood
Director - Energy Systems
Alachua County Public Schools