Condensing Unit Replacement | Condenser Only, or Complete HVAC System?

One of the most common questions people ask about replacing the central air conditioner, is if they can replace only the condensing unit, or do they have to replace the entire air conditioner which includes the evaporator coil, line set, furnace or air handler, etc.

Out of sight, out of mind… is one of the best phrases we can think of when it comes to choices like this, since most homeowners in Charlotte rarely even realize that there’s an internal component (the evaporator coil, air handler, etc) with such importance in the entire home central air conditioning system.

In this Charlotte Air Conditioning FAQ article, we want to address the common question about condensing unit replacement, and whether you can change only the outside condenser, or the whole system.

If you prefer, you can get Free Repair Quotes anytime, to compare the AC repair, versus replacement.

Condensing Unit Replacement for Your Charlotte Home

When it comes to replacing your Charlotte central ac system, there are some things that MUST be replaced, and others which may or may not be required. Your contractor should be able to explain these to you as well, but being educated about what you currently have and whether it needs to be changed out is just good practice!

Condensing Unit Replacement

Since we already established replacement of the outside condenser, there is no need to explain more. Obviously, the unit itself must be changed out.

Evaporator Coil (Cased or Uncased Coil)

The evaporator coil, housed directly within or onto the top or side of the gas furnace or air handler, MUST BE MATCHED to your outdoor condensing unit. The refrigerant needs to be the same, the capacity or size needs to be the same, the SEER rating needs to be the same, and in some cases, manufacturer warranty requires they be changed at the same time.

The ONLY time you want to keep an existing evaporator in your system is if the outdoor condenser fails prematurely in the first 3-5 years of operation, (lightning strike, flooding, etc) and it can be replaced with an exact duplicate product. In other words, unless you are advised to keep the existing coil, it should always be changed out with a new evaporator!

When its OK to Keep the Existing Evaporator Coil

  • Less than 5 years old and outdoor unit is exact duplicate replacement.
  • Contractor has tested indoor coil to be sure it was not the cause of the failure.

When you MUST Change the Indoor Evaporator Coil

  • Different size or capacity.
  • Coil designed for lower efficiency rating or TXV system.
  • Different refrigerant type (r-22 or r-410a, etc)
  • Manufacturer required for warranty purposes.
  • To achieve a specific SEER rating for tax or energy rebates.

As previously stated… unless it was a premature failure of the outside condensing unit, it’s recommended to change it to match your new outside unit.

Copper Lineset

The copper lineset is a set of two copper tubes that connect the outdoor condensing unit to the indoor coil. One of the lines is wrapped with insulation to keep the refrigerant as cold as possible as it travels from the outside to the coil, and the other line is exposed and returns the refrigerant to the unit after it has passed through the coil.

In many cases, the line-set may not have to be replaced as long as its thoroughly cleaned (vacuumed) and tested to assure it will not leak refrigerant. That said… this is another area where replacing the lineset is simply a good practice, to assure the units work properly and achieve the highest efficiency they are designed for.

When its OK to Keep the Lineset

  • Contractor has thoroughly tested and cleaned the existing lineset.
  • Lineset meets the requirements of the new unit being installed. (tubing sizes)

When you Might Have to Change the Lineset

  • Different size unit.
  • Damage or corrosion on the joints of the copper tubing.
  • Old lineset may be leaking and it makes sense to replace versus the cost to repair a lineset.
  • Changing to a different brand name on the equipment. Different brands use different sizes in some cases.
  • To achieve the desired efficiency or seer rating.

Gas Furnace or Air Handler

Probably the biggest question most homeowners have is whether they MUST swap the furnace or air handler at the same time as the central air conditioner unit. After all, in the summer time you won’t need heat anyhow and if the blower is working fine, why not just leave it in place and replace it as needed?

Many contractors will swap the furnace at cost when they are already there doing the work on the rest of the system! The reason for this, is that most of the system is already apart, and to replace the furnace is a no-brainer when it comes to cost! In fact, if your contractor did not suggest or at least offer a full replacement at the time of the condensing unit replacement, you should get a second opinion!

If you recently replaced the furnace or air handler (within 7-10 years, separate of the ac unit) there may be no clear reason to have it replaced, unless its not compatible with the new unit.

Always Get at Least 3 Replacement Quotes

One of the most common mistakes a homeowner makes when replacing any part of their Charlotte HVAC systems, is not getting at least three competitive cost estimates! You would be surprised to know that the same exact system can be several thousands of dollars difference from one company to the next!

Always get at Least 3 Quotes!

Tell us, when you last had the air conditioner replaced, did they replace just the condenser or the entire hvac system?

Ratings and Comments

5 Responses to “Condensing Unit Replacement | Condenser Only, or Complete HVAC System?”
  1. Billy says:

    we got the bad news that our compressor went bad on a 4 year old ac system. the guy that replaced it said that since our inside coil was only 4 years old and already has an expansion valve, he could replace it without doing the whole system.

    we had 1 other contractor tell us the whole thing had to be changed out for $4500. called a second company and $1400 later, we have a working ac system again. he replaced the entire outside condenser, recharged the system, and guaranteed for 1 year. In and out in 4 hours.

  2. Mark says:

    @ Billy –

    Thanks for the info about your air conditioner replacement and the fact that they only needed to change out the outside condensing unit, versus the entire unit.

    Do you know why they chose to replace the entire outside unit, versus ONLY the compressor inside of it? I would have assumed the compressor was under warranty still.

    Charlotte HVAC Guide

  3. Jess says:

    we had a new ac installed this morning. The company was able to change just the outside box and the coil in our furnace. We had one quote that was $8200 for a whole new system with furnace and stuff, we got the new ac and coil for $2450. Pays well to shop around and know what your talking about. thanks to this site for helping know my options! Ya’ll rock!

  4. Janice says:

    My outdoor heat pump is less than 3 years old. I have a 1 yr old indoor furnace that was installed last Winter by another company (NP). When NP installed the indoor unit, the heat pump received a new compressor.. and they changed the line set (from bad to worse.) It now goes in 2 different directions and the buried line we suspect is sitting in water because it was not capped off properly but rather is sitting in a crinkle pipe. So after only a year the compressor is shot again. Is the poor installed line set a reason that the compressor keeps going out? NP wants to bypass getting a new compressor and pushes to install another outdoor unit instead. My “second opinion” tech believes that the real problem is NP’s poor line set– But NP says their work is fine. I’m getting a lot of conflicting info about line sets. Please help.

  5. Ted says:

    My York unit condenser 3 ton was not cooling enough due to freon drops to 10 psig, I added freon and works good, 2 months later the freon drops again. This unit and furnace is almost 25 yrs old, I’m thinking to replaced the condenser to 3.5 ton due to my one added room above the garage. What is your recommendations? Looking forward to your insight. Thank you.

Join or Start the Discussion

We love hearing from readers like yourself! Share your thoughts or share your own experience with the subject