A Homeowner's Ultimate Guide to Choosing the 'Forever' HVAC System

Choosing a new heating, ventilation, and air conditioning setup for your home is a big decision that requires a lot of careful consideration. The best HVAC system for your home is one that falls within your budget, keeps you and your family comfortable, and provides a level of efficiency that helps keep heating and cooling bills to a minimum. Meeting these standards means thinking about things like home size, the climate in your area, your lifestyle, your existing system, and more.

Knowing how to find the right setup for your home means considering different types of equipment, sizing your system properly, going with an efficiency rating that makes sense for your climate, and, above all else, hiring a reliable installer. It’s a complicated process, but putting in the work now will mean decades of worry-free living, comfort, and low utility bills.

Before You Compare Brands: What Really Matters?

A lot of guides online will dive right into comparing the different brands when discussing how to buy a new HVAC system. While that’s sometimes useful, there are several other considerations that are far more important that affect upfront costs, long-term savings, and system lifespan.

Getting the Right Type of HVAC System

First and foremost, you should think about what type of system is right for you. The answer depends on the climate in your area and your existing system, specifically whether you have reliable ductwork installed already, but efficiency, sustainability, and aesthetic preferences are important to think about, too.

There are a few different types of HVAC systems to choose from:

• Split systems: Split systems are the most common types of HVAC systems. They have a standalone boiler or furnace in addition to a central AC system. They’re the most expensive to install but generally have the greatest heating and cooling capacity.

• Packaged system: Packaged HVAC systems are like split systems in that they use different equipment for heating and cooling, but in a packaged system, all equipment comes in a single package. Maintenance costs will still be relatively high, but the labor costs for installation will be lower.

• Hybrid split systems: Hybrid split systems are similar to split systems, but instead of a standard central AC system, they use a heat pump for cooling. The heat pump can also provide heat in mild temperatures, but there’s a backup boiler or furnace for ample heating in extremely cold weather. These systems are reliable and energy-efficient, and they’re often more affordable than standard split systems.

• Heat pumps: Heat pumps are becoming more popular because of their efficiency and advancements that make them suitable in colder climates. They use electricity to move heat rather than burning fuel to generate heat. Heat pump systems can provide both heating and cooling in one system, so they’re more affordable than split systems, although they’re not ideal in extremely cold climates. Air source heat pumps are the most popular, but geothermal heat pumps can be good options in extremely cold climates.

• Ductless mini-splits: Ductless mini-splits are a type of heat pump, but rather than making use of a centralized system, they use indoor units mounted to your wall. These can be unsightly, but if you don’t mind the look, they’re extremely efficient, affordable to install, and give you maximum control over temperature in different areas of your home.

Many homeowners decide to stick with their existing type of system and simply replace the furnace/boiler and cooling system with a newer, more efficient model. But if you’re choosing an HVAC system for new construction, or you’re considering switching to a different system, it’s useful to know about the available options.

Split System

Packaged System

Hybrid split

Heat pump

Ductless mini-split

Getting the Right Size (It's Not Just About Power)

Once you figure out what type of HVAC system is right for you, you’ll need to determine what size system suits your home and your lifestyle. Different types of systems use different size ratings, but it all boils down to how large of a system you need to heat and cool your space efficiently.

Some types, like split systems, are measured in tons, with each ton equaling 12,000 British thermal units (BTUs) per hour. You want to match your system’s output in BTUs to your heating and cooling needs.

Lots of online guides will estimate BTUs needed per square foot, and while this can give you a general idea of system size, it’s really not accurate enough to base your system on. The only way to know what size HVAC system you need is to have a professional load calculation done. This is commonly called a “Manual J” calculation. In addition to home square footage, a Manual J calculation will consider the following:

• Ceiling height (because the space you’re heating and cooling is in three dimensions and not two)

• The quality and age of your home’s insulation

• The quality and insulative value of your windows and doors

• Shading on your property

• Home layout

• The direction your home faces and how much direct sunlight it receives

Why is HVAC system size so important? A system that’s too small will struggle to keep up with demand. It will be more likely to break down, especially in extreme weather when you need it most, it will require more maintenance, and it won’t keep your home as comfortable as it should. A system that’s too large will cycle on and off rapidly, which can also limit system lifespan and lead to humidity problems. Both undersized and oversized systems will run inefficiently and drive up utility costs.

Understanding Efficiency Ratings (SEER2, AFUE, HSPF)

HVAC efficiency depends on more than just your system’s size, though; you’ll also have to choose an efficiency rating, which determines your unit’s heating and cooling capacity based on the fuel or electricity it consumes. Higher efficiency ratings are usually better, but it’s not always worth investing in the highest efficiency rating possible.

Efficiency ratings can be confusing because there are a bunch of different acronyms floating around that all mean different things. The only three you need to know about are SEER2, AFUE, and HSPF.

SEER2, or seasonal energy efficiency ratio 2, tells you how much cooling your AC will provide per unit of electricity. You don’t have to worry too much about what the specific number means; all you really need to do is choose a rating within a range that suits your climate and your budget. A low-efficiency AC will have a SEER2 rating under 15. ENERGY STAR-certified units have a SEER2 rating of 15 or above. The highest efficiency ACs can have SEER2 ratings of 20 to 28.

Annual fuel utilization efficiency, or AFUE, is a rating for furnaces. Similarly to SEER2, it tells you how much heating power you can expect per unit of fuel (natural gas, propane, or oil). Again, you don’t need to worry much about what the specific numbers mean. Rather, you just need to choose an AFUE that makes sense for your climate and understand that units with a higher AFUE rating are more expensive but will reduce utility costs over time.

HSPF, or heating seasonal performance factor, is like AFUE but for heat pumps. It’s different from AFUE because heat pumps don’t burn fuel, but the idea is similar: it tells you how much heating capacity your heat pump is capable of, given a certain level of electricity consumption. 

While it may always seem like an obvious choice to invest in the highest-efficiency possible, the Department of Energy warns that there are diminishing returns. If you live in an extreme climate, an HVAC system with a peak efficiency rating may be worthwhile, but in a moderate climate, you don’t need such high efficiency ratings, so you won’t see long-term savings that justify the higher cost.

Much like HVAC system size, you should speak with your pro to determine what efficiency rating makes sense for your home, climate, and budget.

The Installer Matters More Than the Brand

Finally, a crucial thing to remember is that the installer you choose to set up your new system is always going to matter more than the brand.

HVAC brands can vary a bit in average lifespan, but an unreliable installer putting in a top-of-the-line system and making mistakes is going to cost you more in repairs and inefficiency than you’d face if you had a reliable installer put in a middle-of-the-road brand. Plus, since your installer is the one sizing your system and helping you choose an efficiency rating, it may come as no surprise that the installer is one of the most important decisions you’ll make when deciding on a new system.

A reliable installer will perform a Manual J calculation to size your system perfectly, help you decide on an efficiency rating that’s ideal for your climate, make sure ducts are sealed to prevent air leaks and major energy losses, and maintain your HVAC warranty. What does that mean for you? More comfort, lower energy bills, a longer system lifespan, a lower risk of breakdowns, and less regular maintenance over time.

How to Choose the Right Contractor: 4 Critical Points to Address Before You Buy

Now that you know that your installer matters more than brand ever will, we can get into how to choose a reliable HVAC contractor and how to lean on them to find the best system for your home.

First, rule out any contractors that offer a quote without performing a Manual J calculation. This is a major red flag and can quickly narrow down your list of potential pros. After that, there are four critical points we recommend addressing with each expert you’re considering. These can help you decide on the best equipment, and the answers can either establish trust in the contractor or highlight that they may not be as professional as they claim.

1: What Technology Level Fits My Comfort Goals?

First, discuss the available technology with the pro to see how knowledgeable they are on the different options and help you decide which is best for your home. You can start by asking about the compressor options for your AC system and/or heat pump. Compressors are essentially what move refrigerant through your system to move heat around. There are three types of compressors:

• Single-stage: Single-speed compressors are either on or off, similar to a standard light switch. When it’s on, it’s running at full capacity, and it can only regulate indoor temperature by cycling on and off. These are the least efficient and can be noisy, but they’re the most affordable.

• Two-stage: Two-speed compressors are like the fans on most vent hoods, as they have three settings: off, low, and high. In moderate temperatures, they operate on the low setting to reduce noise, improve efficiency, and reduce cycling, which can prolong system lifespan. The low and high settings also mean more even and comfortable temperatures in your living space.

• Variable-speed: Variable-speed compressors are like lights on a dimmer switch; they can be off, operating at full capacity, or operating at a variety of levels in between. These are the most expensive units but provide the most comfort, the highest level of efficiency, and the lowest utility bills.

Pay attention to how your contractor speaks about these options, what they recommend, and why. Less reputable installers may just say you should always go with a variable-speed system because it’s “better,” but that’s not always the case. It may be an unnecessary upgrade in a moderate climate. Use this conversation to decide on a system type and also to gauge your contractor’s knowledge and honesty.

2: What Efficiency Rating Makes Sense for My Climate?

Next, ask your contractor what efficiency rating makes sense for your climate. Remember that efficiency ratings, including the commonly referenced SEER ratings and their updated standard, SEER2 for AC systems and heat pumps when they’re cooling, AFUE for furnaces and boilers, and HSPF for heat pumps when they’re heating. These are like the miles-per-gallon rating for your car: the higher the rating, the less you’ll spend on fuel (natural gas, oil, propane, or electricity).

In hotter climates like Florida and Arizona, investing in the highest efficiency possible for your AC (ideally 18 SEER2 or higher) usually makes sense. It will cost you more upfront, but you’ll offset that added cost in utility bill savings over time.

In moderate climates, like New York, you’ll almost never see savings that justify investing in equipment with the highest rating. In a place like northern Michigan or northern Maine, a mid-range SEER2 rating for your AC unit is probably best for balancing upfront cost and long-term savings, but investing in a furnace or boiler with a high AFUE rating or a heat pump with a high HSPF rating is well worth the money for efficiency through the long, cold winters.

Ask your contractor what efficiency ratings they recommend, and be wary of pros who say that “higher is always better.” That’s not true, and it’s a strong indicator that the contractor is just trying to upcharge you for equipment you don’t need.

3: How Do I Evaluate the Warranty?

Next, ask your contractor what equipment brands they work with and how the warranties compare. Brands vary widely in their warranty coverage, so while a contractor may say they only work with a particular brand because of reliability, you should do your own research to compare.

There are three types of warranties to consider:

• Parts warranty: This covers most parts and components aside from your compressor. Most manufacturers include a 10-year parts warranty, but you usually need to register your product online. Make sure you register after the installation. Some reputable installers will help you with that process.

• Compressor warranty: Compressors are the most critical components in AC systems and heat pumps, and since they work tirelessly, they’re often the first to fail. Most manufacturers offer a compressor warranty of between 5 and 10 years. Make sure to note if the warranty covers parts and labor or just parts.

• Labor warranty: Finally, the labor warranty is offered by your installer and not the manufacturer, although it’s sometimes confused with manufacturers covering parts and labor for breakdowns related to equipment quality. A true labor warranty guarantees that the installation itself won’t be the cause of problems. The mere presence of a labor warranty is a good sign that you’re working with a competent installer.

Some manufacturers, like Trane, offer optional extended warranties for an additional fee. You can consider paying for the added coverage for peace of mind.

4: What Should I Ask Every HVAC Contractor?

Finally, there are a few key questions that you should ask each contractor you haven’t yet ruled out. These are some of the most important things to ask your pro, as their responses can help you determine if the pro you’re speaking with is really worth considering for the job.

• Are you licensed, bonded, and insured? A specific HVAC license may not be mandatory in all states, but ensure your pro at least has a general contractor’s license or a more specific license if your state requires one. Hiring a bonded and insured contractor helps ensure they’ll meet their contractual obligations with you and that you’ll be protected if they cause damage to your home or get injured on your property.

• Will you perform a "Manual J" load calculation to determine the exact size system my home needs? Remember that sizing your system properly means improved comfort, good efficiency, and lower utility bills. Always avoid contractors who size your system based on square footage.

• Will you provide a detailed, itemized quote? Reputable pros have nothing to hide and should have no issue providing an itemized quote that includes a separate line item for labor.

• What is your company's labor warranty? Some installers don’t offer a warranty for their installation labor. That’s not always a red flag, but working with a pro who does offer one is a good idea for peace of mind.

How To Get the Best Deal on a New HVAC System?

Installing a new HVAC system can cost well over $15,000, so many homeowners look for ways to get the best deal possible. There are a few strategies you can employ to keep costs low:

• Time your system replacement properly: HVAC companies are usually busiest in the spring and the fall, which are the most convenient times to replace your system. Waiting until the summer or winter could mean lower demand and slightly lower labor costs.

• Choose the efficiency rating you need: Remember that higher efficiency ratings aren’t always better, as peak efficiency won’t offset higher HVAC installation costs in moderate climates. Speak with your contractor about the rating that works for your area.

• Choose the best type of HVAC system for your needs: The different types of systems vary widely in price. Consider ductless mini-splits to keep installation costs down, or a heat pump system to reduce operating costs over time.

• Take advantage of rebates and incentives: If you invest in a high-efficiency system, you may be able to take the home energy efficiency tax credit (effectively saving up to 30% of your total if you owe enough in taxes), as well as other credits and rebates from your state, local municipality, or utility company.

• Prioritize a reputable installer over high-end brand: Remember that a mid-range brand installed by a reputable professional will outperform and last longer than a high-end system that’s poorly installed. Invest in the installer first and consider the brand second.

• Get multiple quotes: Finally, get at least three itemized quotes from contractors in your area so that you can compare to see if any of them are overcharging for labor or equipment.

Is Financing a New HVAC System a Good Idea?

HVAC systems are expensive, no matter what kind of deal you’re able to secure, so you may need to consider financing yours. You have many options for financing, including the following:

• Contractor financing

• Home equity line of credit (HELOC)

• Home equity loan

• Cash-out refinance

• Home renovation loan

• Personal line of credit

• Credit cards

• Government loans for efficiency improvements

The best way to finance a new system depends on your system costs, how much money you have to put toward a down payment, what kind of equity you have in your home, and how quickly you need to replace your existing system. No matter which option you choose, there are some pros and cons to consider when compared to paying in cash.

Pros and Cons of Financing a New HVAC System

Our Final Recommendation: Your Clear Next Step

While there’s no single HVAC system that’s perfect for everyone, the best option for you is the one that can heat and cool your home efficiently, is powerful enough to maintain comfortable temperatures in your climate, and is installed by a reputable HVAC contractor.

Provided you have a reliable pro on your side, choosing the right type of system, the ideal size, and the proper efficiency for balancing upfront and long-term costs becomes relatively easy. Start by choosing a professional you can trust, and lean on them to ensure you get a system that will serve you well for decades to come.

FAQ: Choosing the Best HVAC System

The best type of HVAC system depends on many factors, including your home’s square footage, ceiling height, climate, budget, lifestyle, and whether or not you have ductwork already installed. A home in a hot climate like Arizona that rarely sees temperatures below freezing can get away with a mid-grade heat pump for heat but benefit from a high-efficiency central AC system for cooling. Conversely, a home in Northern Maine can use a heat pump for cooling but really needs a high-output furnace or boiler for adequate heat, ideally with a high AFUE rating. To figure out what works best for you, have a reliable contractor assess your home and make recommendations based on your needs.

The $5,000 rule for HVAC is a calculation to determine when you should replace your HVAC system rather than repair it. You take the age of your system in years and multiply it by the cost of repair. If that number is over $5,000, you should replace instead of repair. This calculation helps balance the age of your system with the severity of the repair. For example, if your unit is 5 years old and you need a minor repair that costs $500, your calculation (5 x $500) would come out to $2,500. That’s under $5,000, so you should move forward with the repair. For a $1,000 repair on a unit that’s 10 years old, your calculation (10 x $1,000) comes out to $10,000. That’s over $5,000, so replacement is a better financial option.

The answer depends on your goal. UV lights prevent mold growth on evaporator coils and in drain pans. Even the best UV light for HVAC systems won’t have a major impact on air quality, but it can help maintain good HVAC efficiency and avoid clogs in the condensate line and resulting water damage. If you’re looking to improve indoor air quality (IAQ), you should install an air purifier. This will remove allergens and contaminants from the air you and your family breathe to improve safety and health and reduce allergy symptoms. If you’re looking for healthier air, install the best air purifier for your HVAC system you can afford. If you want to avoid mold growth and potential water damage from overflowing drain pans, install a UV light.