HVAC System Replacement

Have questions? We're here to help! Educating our customers, so we can make informed decisions as a team, is a big part of Comfort Monster's mission.


  • Do I need a new HVAC Unit?
  • Economics and Replacing Your HVAC
  • Finding an HVAC Contractor
  • How to select a contractor and purchase a new HVAC system
  • HVAC Options & Accessories
  • HVAC Replacement Basics

Do I need a new HVAC Unit?


Your smart thermostat has a feature to monitor air flow and run times in order to estimate whether your filter might need to be changed – It’s not perfect though, so if you prefer to change it on your own schedule, please go to “Reminders & Alerts” in your thermostat menu and disable the one for filters.
Otherwise, if you see a reminder on your screen and you do need to replace the filter, you can reset it by tapping on the reminder once your filter has been replaced.

Unless your system has a labor warranty and your manufacturer part warranty is still good, chances are that you’ll be paying for warranties. It takes more than a few sentences to explain how service companies are paid and what their relationship is with the manufacturer but we have written a full article to explain why warranty repairs cost what they do.

You may not necessarily expect it with every company, but it’s definitely your prerogative to make sure you understand what is going on with your equipment and you have the knowledge to make a good decision to have it fixed. What your service tech is telling you should make sense and should coincide with the problem you are seeing with your system. To make sure you get the most value from your service call, you might read our guide to a successful HVAC appointment.

It is definitely hard to differentiate between 4.9 stars and 4.7, but there are ways to tell a good company from the rest. Read our article on reading and understanding reviews for service companies.

In fairness, some people feel they are being ripped off when a service company comes out to fix a problem and they get charged a fair price that results in a fair profit for the service company, but they look up the cost of the part and think the markup is ridiculous. Knowing the difference between fair service and rip-off’s can be difficult. Most of the time, the most important thing is making sure you are only fixing things that need to be fixed and have a reference for what a fair price is. This article would be helpful in understanding everything that goes into providing field service that customers sometimes overlook. Also, read our article on reading and evaluating reviews.

Depending on when your system was installed it probably isn’t nearly as efficient as you think it is. Over time HVAC systems decline in performance.. Sometimes significantly when not maintained properly. That being said, the efficiency of your system as it was installed is determined by the combination of parts (if it’s a split system). There isn’t an easy way to determine the efficiency unless you have the AHRI number. You can learn more about AHRI and efficiency here.

The process is simpler than people think. Refrigerant is compressed into a high pressure vapor, condensed into a high pressure liquid and then the pressure is released transforming the high pressure liquid directly into a lower pressure vapor. This vapor is moved through the evaporator coil where the heat (cooling) is transferred to the home via forced air circulation. For more information you can read about the history of the air conditioner and HVAC system components.

It used to be you could park your Trane or Carrier system in the yard for 25 years and hardly touch it and it would run fine. Technically you are losing efficiency as the indoor and especially outdoor coils get dirty, but they would run with no problems. Modern systems are higher efficiency and contain more components that don’t last nearly as long. Properly maintaining your modern HVAC system is critical to its life and efficiency. In many cases, small problems can also lead to big problems. Learn more about why new equipment doesn’t last like the old stuff.

The most common systems are split systems, package systems and mini-split systems. This refers to the design of the system, but beyond that there are heat pumps, A/C and furnaces, and hybrid heat (heat pump and furnace) and A/C. On top of that there are single stage, two stage, and variable. We have a few articles to help you understand that you have. Start with understanding split, package, and mini-split.

HVAC systems are pretty reliable when they are in good working order. Under normal circumstances they should run for years between repairs, however when they get older a variety of components can cause issues. Knowing when to repair or replace can be tricky. We’ve written a guide to help you figure out when it’s time to repair or replace your HVAC system.

Here is a short answer, but for a full explanation, read our guide. If it’s really hot or cold it is very possible it will run all the time. When properly engineered for your home, HVAC systems are sized to meet “design temperatures” in your area. In Raleigh the design temperature is 93 degrees in summer. If you want your house cooler than 75 degrees and the outside temperature is 93 or above, expect your system run continually trying to achieve your desired cooling level. In practice, many systems are oversized by up to half a ton (sometimes more) to achieve cooling that exceeds the ACCA (Air-Conditioning Contractors of America) or local code requirements but when the temperature is extremely hot or cold you can expect extended run times of your HVAC equipment. When temperatures are marginal your system should not run all the time. See our article, 5 Most Common Air-Conditioning Problems and Repairs if you suspect your might have an issue.

The cost is going to vary greatly depending on what’s wrong (or whether more than one thing is wrong). Using our troubleshooting guides you may be able to determine what’s wrong and what the average costs of repair are.

Don’t worry, many air-conditioning problems are not that complicated and may not be that expensive. Use our troubleshooting guides to troubleshoot the most common problems. For most issues you’ll still need a technician but at least you’ll have an idea what the issue might be and what the repair should cost.

There’s definitely things you should consider — it’s important to understand all your options, but also know most things can be added later, so it isn’t critical to get it all done at one time. Check out this list of options you might want to consider.

Without testing the air, you can only determine the quality of your home’s air anecdotally. Meaning if you experience allergies, trouble breathing, frequent sickness, or other signs of poor air, these issues could be unrelated to your air and may be related to external factors or even non-air related issues in your home. We recommend having your air quality tested so you can evaluate the quality of your air and what specific factors may need to be improved.

If your system is installed with a filter box (a place to put a filter right at the unit), this takes the place of the filters that go in your regular return grilles. One of the benefits is that instead of changing multiple filters you can just change one. However, the reason you have filters in your return boxes at all is that they are usually much more accessible than your unit. We have seen some cases where homeowners completely forget about the filter boxes and a filter isn’t changed for an extended period (terrible for your unit). If your duct or return is undersized, installing a filter box right at the unit can reduce your return static pressure which can improve system performance and life.

In short, yes. Humidity has a pretty large impact on how comfortable you feel. Your body is very good at regulating temperature and sweat is one of the ways it does that. This doesn’t mean that humidity is only important when you’re hot enough to sweat. High humidity makes you feel warm and clammy. Reducing humidity can make you feel 2 or 3 degrees cooler when the thermostat is set to exactly the same temperature. Not only do you feel more comfortable but you also save money if your thermostat can be set a little higher.

Yes, definitely. The best time to replace your system would be just before a major failure occurs and during the spring or fall.
…If it was only that easy! Unless you can see the future, you won’t know when a major failure will occur, and they rarely occur during the spring and fall. Typically that happens on the hottest or coldest days of the year. During that period, your HVAC service will likely be slower (especially if you don’t have an existing relationship to get priority service), and you will pay more. So the best way to save money and avoid problems is to have a maintenance agreement with a company you trust. They will keep tabs on the health of your system, and together you can find a time to replace your system when it has provided a good service life but before it gets inefficient and unreliable. You might also read our article with more info about the best times to replace an HVAC system.

Good question.. It’s possible you can get away with just a partial replacement, but there are lots of factors to consider. We have written an article to help, but you probably need to consult an expert you can trust to help make the decision.

This can be very difficult decision without being able to see the future. The short answer is to replace it before repair costs become exhorbitant and reliability becomes inconsistent. The only thing worse than replacing your system too early is spending too much on repairs and then replacing your HVAC system too late. Reading the following guides will help:  Knowing When It’s Time to Repair or Replace Your HVAC System and Common Problems that Usually Mean It’s Time for a New HVAC System 

Unfortunately most of the field personnel in the industry are paid some kind of commission or incentive to sell or develop leads so there is a natural inclination to deliver information that may not be in your best interest. It is highly recommended to get a second opinion and read our article on common HVAC replacement scams to avoid.

Articles & Guides

More Information

Complete HVAC Replacement Guide

Read everything you need to know about buying a new HVAC system.


Articles at a Glance

Do I need a new HVAC Unit?

What’s the real truth about R22/Freon phase out and prices? Can I Replace Just Part of My HVAC System? Are New HVAC Systems Less Reliable Than Old Ones? 5 Ways HVAC Efficiency Can Decrease Over Time Common HVAC Replacement Scams to Avoid How Long Should My HVAC System Last? (and Knowing It’s Time to Replace) Is there a best time of year to replace my HVAC system? Common Problems that Usually Mean It’s Time for a New HVAC System Knowing When It’s Time to Repair or Replace Your HVAC System Repairing or Replacing Your HVAC System After a Flood

Economics and Replacing Your HVAC

How to Negotiate the Best Deal on a New HVAC System Guide to HVAC Warranties and Repairs Guide to HVAC Repair/Service Pricing Guide to Rebates, Tax Credits and Manufacturer and Dealer Incentives How Much Does a New HVAC System Cost? 5 Misleading Ways Replacement HVAC Systems are Advertised Saving Money on Your Air Conditioning This Summer Guide to HVAC System Replacement Financing Is there a best time of year to replace my HVAC system?

Finding an HVAC Contractor

Carrier and Comfort Monster Give the Gift of Warmth this Christmas Efficiency Ratings, System Components, AHRI

How to select a contractor and purchase a new HVAC system

5 Misleading Ways Replacement HVAC Systems are Advertised How to Read and Evaluate Reviews for Home Services Companies 7 Questions To Ask Your HVAC Salesperson That You Didn’t Know You Could Ask What is an Applied Product and Why are HVAC Systems Considered an Applied Product? What Brand of HVAC Equipment is the Best? 5 Important Considerations for a Quality HVAC System Installation Efficiency Ratings, System Components, AHRI Common HVAC Replacement Scams to Avoid Guide to Choosing a Thermostat

HVAC Options & Accessories

Would Installing a Programmable Thermostat Really Save Me Money? Guide to HVAC System Options and Accessories Intro to How a Residential HVAC Zoning System Works Guide to Choosing a Thermostat

HVAC Replacement Basics

6 Signs That Point to an Unhappy Furnace Air Conditioner Noises You Shouldn’t Ignore HVAC Brand Buyer’s Guide Single Stage vs. Two Stage and Variable Speed How Does a Heat Pump Work? How Does a Central Air Conditioner Work? Ducting/Ductwork and Ventilation Intro to How a Residential HVAC Zoning System Works Efficiency Ratings, System Components, AHRI Guide to Understanding and Choosing Efficiency in a New HVAC System HVAC System Components