It’s 2023. What do I need to know about heat pumps?

[Terry Wawro]

Any advice on replacing an old heat pump?
One of our heat pumps is almost 18 years old. It’s a basic, single phase Trane unit. It’s not in the best shape and I know it’s not a matter of if, but when it will need to be replaced. Before that happens I’d like to be better informed. We are total electric. It’s now 2023, what should I look for?

[Brian Elfert]

I think a lot of it depends on your location. The big thing in heat pumps is the ability to work in colder weather and also two stage. Two stage can make your house feel more comfortable when heating as the heat runs longer and more often. Also, for cooling two stage can remove humidity better as it will also run longer. If you're in an area with heavy cooling loads you might not need to worry about humidity control so much except maybe at the beginning and end of the cooling season. If your heating load is really low you're not going to care as much about the heat side of things. My friend lives in Fort Myers. He has heat pumps, but he only runs the heat two to four weeks per year. Most of the time he is running them in cooling mode.

[John K Jordan]

Any advice on replacing an old heat pump?
One of our heat pumps is almost 18 years old. It’s a basic, single phase Trane unit. It’s not in the best shape and I know it’s not a matter of if, but when it will need to be replaced. Before that happens I’d like to be better informed. We are total electric. It’s now 2023, what should I look for?


You might be surprised at the better efficiency ratings of some of the newer models. My two Trane heat pumps have multi stage operation which I’m told helps with efficiency. I have not researched this in the last 5-6 years so i’m not up on the latest technology.

I’d use a reputable firm than can do the analysis to properly size the unit based of volume, insulation, window number/type, etc. If you have architect friends ask them who they use for their personal and office heat and cooling needs. I shopped around and the small recommended dealer was 1/2 the cost than another larger Trane company. This dealer even let me do most of the installation of my shop heat pump at a huge additional savings.

I’d shop in the “off seasons” when the companies are not overbooked with frantic customer calls to fix their heating or cooling.

[Tom M King]

If it's working without having to call for service in the past year, I would keep using it. Even the most efficient regular heat pumps are still WAY behind mini-splits in efficiency. Mini-splits not only have variable speed fans, but also variable speed compressors, and vary the amount of refrigerant in the system by demand.

Regular heat pumps, like your Trane, have a long ways to go to catch up with today's mini-split, but there is not a single good reason why they don't, and I expect some manufacturers would already be working on this.

Also, the type of refrigerant is set to change in not too many years, which always means past refrigerants go up in price. R410a runs at extreme pressure which has to cause more wear and tear than lesser pressure would, and always makes leaks more likely.

In short, I think we're too close to getting better stuff to replace regular heat pumps with to swap out a system that's working now.

I also have a 2006 Trane unit, probably not much different than yours. I work on them myself and this one is in a house we've only owned for a few years. It suffered several severe issues from improper installation that would have killed lesser units. I ended up replacing the leaking linesets that no doubt were unflushed old R22 lines from much older units, and the old Trane is right back to running like a new one. Their slogan is: "It's hard to stop a Trane", and personal experience tells me that's true.

[Brian Elfert]

The Bosch IDS 2.0 heat pump has most of the features of the mini-splits, but the equipment is very expensive. You could probably have a lesser heat pump installed, labor and all, for the same or less cost than what just the Bosch equipment costs. The equipment that works with the new refrigerants will likely be very costly at the start. Manufacturers will want to recoup R&D money they spent to design the new equipment.

[Terry Wawro]

I'm in the upstate of SC so cooling is my biggest need. Still, it got down to 5 degrees a few days before Christmas. That almost never happens. I like the idea of a two stage as I the unit is for our lower level with a walkout basement., It could benefit from the added de-humidification.

I know it's running R22 because I the service guy had to add 2lbs about 16 months ago. It was $100 / lb back then. I don't even know if it's still available or not.

I agree, mini-splits are so much more efficient.

[Tom M King]

If it was mine, and I intended to replace it, if it's working, I'd check the line temperature and pressure on a day with moderate air temperature, and if it was what R22 is supposed to be I'd recover it into a new or uncontaminated tank and keep it. It's valuable stuff now. Someone working for a company probably won't do that though.

If you do change it, don't have them take the time and expense of flushing the old lineset. Just replace the lineset with new lines. The oils are different in the different types of refrigerant, and you don't know how meticulous the person who brazed the old lines was about keeping the insides clean anyway. The difference in cost shouldn't be much.

[Lee Schierer]

Your first step is to see what if any state, federal or local rebates and credits from your local utility company offer for heat pumps. Then determine whether you are going to use an air source or ground source system Generally speaking ground source systems are more efficient than air source system.

[Carl Beckett]

And upgrade/fix any insulation or leaks.

[Terry Wawro]

If you do change it, don't have them take the time and expense of flushing the old lineset. Just replace the lineset with new lines. The oils are different in the different types of refrigerant, and you don't know how meticulous the person who brazed the old lines was about keeping the insides clean anyway. The difference in cost shouldn't be much.

I wish it was easy but after finishing our basement, our existing line set is now buried behind sheetrock in the ceiling and an outside wall. Good idea on capturing the R22 though.

[Tom M King]

The lineset I replaced was buried too. I ran another one on the outside, and just left the old lines in the wall.

[Ole Anderson]

You should at least be familiar with the newest VS inverter heat pumps. Very efficient like mini-splits, and quite expensive.

[Jack Frederick]

Our new home as of Feb is 1450 sq ft. There is a 95% eff gas furnace with a conventional single stage R22 condensing unit. It is enormous. I am considering converting the furnace to a HP. My first step is to determine the duct works condition. In our current home the duct work was so poorly done I pulled the entire system and went with mini-splits. 12 yrs in we are very happy with it as the solar system provides the power. A fairly new option is to use a 24 or 36kbtu Fujitsu mini-split condensing unit with their new(er) variable speed air handler. If the duct work proves out that would likely be my first option. If not then it is on to the mini-splits. A 3 ton mini condensing unit is less than half the dimension of the current condensing unit an much quieter.

[Terry Wawro]

I'm smart enough to know what I don't know. Here are a few things I'm puzzling about.

My unit is single stage. It works, but do I want to look at a dual stage or even a variable-speed unit. Or, are they finicky, complex and break down more often?

What is the SEER sweet spot for efficiency vs cost and reliability in 2023?

R22 is phased out. Is there another refrigerant being phased out in the next few years? If so, a system running what refrigerant should I be looking at?

I'd like to go to a mini-split but the rooms are too divided and separated by a long hallway. Got to stay with a duct-ed system.

[Bill Dufour]

Location, Some countries have outlawed older refrigerants so you may have more limited choices depending on where you live,
Bill D

[Brian Elfert]

If it was mine, and I intended to replace it, if it's working, I'd check the line temperature and pressure on a day with moderate air temperature, and if it was what R22 is supposed to be I'd recover it into a new or uncontaminated tank and keep it. It's valuable stuff now. Someone working for a company probably won't do that though.


Recovery of refrigerant is required when replacing a heat pump or air conditioner. Any HVAC tech that doesn't have a recovery machine and doesn't recover the refrigerant before replacing the system should be kicked off the premises. If they are willing to take a shortcut by not recovering the refrigerant what other shortcuts are they taking? Recovered refrigerant may legally only be put back into the same unit, or a unit owned by the same owner. It is not legal for an HVAC company to place recovered refrigerant into a unit owned by someone else. The HVAC company is supposed to send the recovery cylinder to a company that recycles or destroys the refrigerant.

I suppose if you have your own recovery machine you could try to sell the used refrigerant on FB Marketplace or similar. I personally wouldn't buy recovered refrigerant to put in my unit due to possible contamination, but it might make sense to use if you have a leaking unit you are trying to get a few more years out of.

[Tom M King]

Of course it would have to be recovered. I don't have anything that runs R22. I have friends that do though, including one 94 year old lady who lives on SS, and I wouldn't think about selling it. I said if it was mine. I'm sure more than a few pounds of recovered R22 has been sold by some HVAC guys to people that don't know the difference.

Recovered with a filter in the line to the recovery machine, and if it tests like it should for pressure at a temperature, there is no reason to think it wouldn't run in one of the old units that runs it.

That's also why I said I'd test it in the system if the system was running. If there was a question about it being contaminated, I would recover it into a container destined for a recycler.

[Alan Rutherford]

Regardless of the details of the system you get, be sure you're getting good avice on the size. This is one subject where bigger is not better than big enough, it's worse. The ideal system will run 100% of the time on the hottest day it's designed for. On the average day, a system with too much capacity will short-cycle. Not good for efficiency or the life of the system.

Many if not most installers will look at your house and say you need X tons and never do the calculations, which can take some time. Google "Manual J" to understand what's involved and so you know what to ask for. You can also find resources to do it yourself, which is not too difficult.

[Terry Wawro]

Regardless of the details of the system you get, be sure you're getting good avice on the size. This is one subject where bigger is not better than big enough, it's worse. The ideal system will run 100% of the time on the hottest day it's designed for. On the average day, a system with too much capacity will short-cycle. Not good for efficiency or the life of the system.

Many if not most installers will look at your house and say you need X tons and never do the calculations, which can take some time. Google "Manual J" to understand what's involved and so you know what to ask for. You can also find resources to do it yourself, which is not too difficult.

True. The original two heat pump units were identical, although the main floor needs much more capacity than the walk out basement since it's 60% below grade. I've found a couple of sources to do a manual J myself and I'll definitely do one, just to have as a reference.

[Bill George]

In most areas with Codes a Manual J or some sort of approved Heat loss/gain calculation must be submitted with the permit to install new HVAC equipment.
In the old days it was done by seat of the pants or what was on sale at the wholesaler that week. Lots and lots of furnace's were greatly oversized. My house built in the 1960's had a 100,000 input btu gas, now its a 2 stage 96% ECM gas 60,000 btu input.

[Brian Elfert]

Of course it would have to be recovered. I don't have anything that runs R22. I have friends that do though, including one 94 year old lady who lives on SS, and I wouldn't think about selling it. I said if it was mine. I'm sure more than a few pounds of recovered R22 has been sold by some HVAC guys to people that don't know the difference.

Recovered with a filter in the line to the recovery machine, and if it tests like it should for pressure at a temperature, there is no reason to think it wouldn't run in one of the old units that runs it.

That's also why I said I'd test it in the system if the system was running. If there was a question about it being contaminated, I would recover it into a container destined for a recycler.

Sorry, I thought you were implying an HVAC tech would not recover the refrigerant. It would be against EPA regulations for an HVAC tech to put recovered R-22 or other refrigerant into another unit, but I am sure it gets done. The regulation seems a bit silly to me as it means more virgin refrigerant gets produced. Recovered R-22 is probably fine so long as the compressor didn't burn up.

[Dwayne Watt]

In most areas with Codes a Manual J or some sort of approved Heat loss/gain calculation must be submitted with the permit to install new HVAC equipment.
In the old days it was done by seat of the pants or what was on sale at the wholesaler that week. Lots and lots of furnace's were greatly oversized. My house built in the 1960's had a 100,000 input btu gas, now its a 2 stage 96% ECM gas 60,000 btu input.
Furnaces of the '60s and '70s were lucky to be 60% efficient. It is unlikely the unit was oversized for your house since at least 40% of the heat was going out the chimney.

[Bill George]

There is no more legal R22, its suppose to be recovered. For anyone to service HVAC equipment your in violation of EPA rules and its a Federal crime to handle or buy refrigerant without being CFC certified. Thats where you get all these yahoo people with no knowledge folks working on high tech Mini Splits.

[Bill George]

Furnaces of the '60s and '70s were lucky to be 60% efficient. It is unlikely the unit was oversized for your house since at least 40% of the heat was going out the chimney.

Yet in 1982 it was replaced with a 95% Lennox Pulse :) which was a clunker when I replaced with that 2 stage Trane in 2007. Yes I did a ACCA Manual J.