Should I get a non-HFC air conditioner? If so, where?
January 24, 2019 11:18 AM Subscribe
Hi. I bought an old house with an old central AC. I would like to replace it with a model that uses a non-HFC refrigerant.
The house is almost 1500 square feet. The 3-ton central AC/H unit is about 12 years old. I'll probably have to replace it soon, and I'd like to use a refrigerant that doesn't contribute to global warming.
I don't see anything for sale around me that uses the newer refrigerants. Except on Alibaba.com.
I did see an amateur video on youtube where some guy loaded propane (R-290) into his older AC system, but I don't know if that's a good idea.
Do you have any suggestions?
The house is almost 1500 square feet. The 3-ton central AC/H unit is about 12 years old. I'll probably have to replace it soon, and I'd like to use a refrigerant that doesn't contribute to global warming.
I don't see anything for sale around me that uses the newer refrigerants. Except on Alibaba.com.
I did see an amateur video on youtube where some guy loaded propane (R-290) into his older AC system, but I don't know if that's a good idea.
Do you have any suggestions?
Response by poster: That certainly makes sense. Any perspective on where I can get a non-HFC AC unit? I know California has now banned new units with HFC refrigerants, but just don't see any for sale that I know of.
posted by atchafalaya at 11:41 AM on January 24, 2019
posted by atchafalaya at 11:41 AM on January 24, 2019
Best answer: I am not sure that residential air conditioning systems using refrigerants with significantly lower global warming potential (GWP) than R-410a are commercially available yet in North America. A couple things to consider, though:
High-GWP refrigerants only cause global warming if they are released to the atmosphere. Keeping your air conditioning system inspected and well-maintained would be a good step toward avoiding releasing its refrigerant into the atmosphere.
Unless there is another reason than its age, you might not need to replace your air conditioner as soon as you think. Useful-life estimates for central AC units are all over the board, but it is not altogether uncommon for them to run for 20-25 years. Waiting a few years if yours is in good working condition would allow more time for lower GWP units to become available.
Finally, let's discuss how bad it would be from a global warming perspective if all the refrigerant did leak out of your air conditioner. R-410a has a GWP of 2,088. This means that, a pound of R-410a, if released into the atmosphere, will trap 2,088 times more heat in the atmosphere than would be caused by releasing a pound of CO2 into the air.
An average 3-ton residential central air conditioner has about 8 pounds of R-410a in it. If released, this would be equivalent to releasing 16,704 pounds of CO2.
By way of comparison, burning one gallon of gasoline in a car engine releases about 20 pounds of CO2 into the atmosphere. A US-average car gets about 25 mpg, so releasing your air conditioner's R-410a into the atmosphere would be similar to driving about 20,000 miles in a car. Certainly this still isn't good, but it may help put the risk you are looking at into perspective.
posted by Juffo-Wup at 12:17 PM on January 24, 2019 [5 favorites]
High-GWP refrigerants only cause global warming if they are released to the atmosphere. Keeping your air conditioning system inspected and well-maintained would be a good step toward avoiding releasing its refrigerant into the atmosphere.
Unless there is another reason than its age, you might not need to replace your air conditioner as soon as you think. Useful-life estimates for central AC units are all over the board, but it is not altogether uncommon for them to run for 20-25 years. Waiting a few years if yours is in good working condition would allow more time for lower GWP units to become available.
Finally, let's discuss how bad it would be from a global warming perspective if all the refrigerant did leak out of your air conditioner. R-410a has a GWP of 2,088. This means that, a pound of R-410a, if released into the atmosphere, will trap 2,088 times more heat in the atmosphere than would be caused by releasing a pound of CO2 into the air.
An average 3-ton residential central air conditioner has about 8 pounds of R-410a in it. If released, this would be equivalent to releasing 16,704 pounds of CO2.
By way of comparison, burning one gallon of gasoline in a car engine releases about 20 pounds of CO2 into the atmosphere. A US-average car gets about 25 mpg, so releasing your air conditioner's R-410a into the atmosphere would be similar to driving about 20,000 miles in a car. Certainly this still isn't good, but it may help put the risk you are looking at into perspective.
posted by Juffo-Wup at 12:17 PM on January 24, 2019 [5 favorites]
One other note: Propane does have a very low GWP of approximately 3, and is, I think, one of the alternative refrigerants that the industry is looking at. But there is a big difference in safety (and probably performance) between an air conditioning system that is designed to be used with propane refrigerant and one that was designed to be used with a non-flammable gas that someone later filled with propane. Please do not attempt to charge your R-410a air conditioner with propane.
posted by Juffo-Wup at 12:23 PM on January 24, 2019 [1 favorite]
posted by Juffo-Wup at 12:23 PM on January 24, 2019 [1 favorite]
Juffo-Wup has a good point in that unless your AC system is broken, the most environmentally responsible thing to do is probably to just maintain it and keep it in place. When it does need to be replaced, be sure to hire a reputable contractor who
will make sure that the refrigerant is properly recycled. (Not all will do this, there is a solid gray market for used refrigerant, especially old R22—my impression is that more "corporate" outfits are generally more likely to correctly recycle than guy-in-a-truck type outfits.) This will ensure that it is not released into the atmosphere.
Like Juffo-Wup, I am unsure if anybody in the US is doing systems with refrigerants that have lower GWP than R-410a. My own company is pretty dang eco-conscious and the systems we install still use it. I am aware that a phase-out is planned, but I don't think it has actually hit consumers yet at least in the USA.
posted by Anticipation Of A New Lover's Arrival, The at 12:27 PM on January 24, 2019
will make sure that the refrigerant is properly recycled. (Not all will do this, there is a solid gray market for used refrigerant, especially old R22—my impression is that more "corporate" outfits are generally more likely to correctly recycle than guy-in-a-truck type outfits.) This will ensure that it is not released into the atmosphere.
Like Juffo-Wup, I am unsure if anybody in the US is doing systems with refrigerants that have lower GWP than R-410a. My own company is pretty dang eco-conscious and the systems we install still use it. I am aware that a phase-out is planned, but I don't think it has actually hit consumers yet at least in the USA.
posted by Anticipation Of A New Lover's Arrival, The at 12:27 PM on January 24, 2019
Your AC is a closed loop system, so if you're using, say, R410A (Ozone friendly, but still way more potent then CO2)— none should leak out into the environment to cause mischief. When you're ready to retire the system, the next system installer can just extract the gas and dispose of it safely.
The new AC inverter have been incredibly more efficient then the older ones for me, so unless your power is solely provided by renewables, a more helpful environmental goal to try and reduce the CO2 being expelled by the power-station down the road. Investing in a more efficient AC system (Highest SEER value) or invest in other adjustments to your home that will allow less general AC usage, reflective window coverings, attic fans, insulation, etc could make the Earth a little happier with your occupancy of it.
CarbonFund says US averages out about 1lb of CO2 per kwh from power-- if your average US home uses about 10,000kwh a year-- over the course of your systems lifetime, you can get a vibe for how you can shift your concerns to make the best overall choices.
posted by Static Vagabond at 12:37 PM on January 24, 2019 [3 favorites]
The new AC inverter have been incredibly more efficient then the older ones for me, so unless your power is solely provided by renewables, a more helpful environmental goal to try and reduce the CO2 being expelled by the power-station down the road. Investing in a more efficient AC system (Highest SEER value) or invest in other adjustments to your home that will allow less general AC usage, reflective window coverings, attic fans, insulation, etc could make the Earth a little happier with your occupancy of it.
CarbonFund says US averages out about 1lb of CO2 per kwh from power-- if your average US home uses about 10,000kwh a year-- over the course of your systems lifetime, you can get a vibe for how you can shift your concerns to make the best overall choices.
posted by Static Vagabond at 12:37 PM on January 24, 2019 [3 favorites]
You won't be able to get someone to fill a system with R-290, which is the only feasible low-GWP refrigerant (besides ammonia, which is... dangerous.) Pretty much any system can be loaded with R-290 and work more efficiently than before. Maybe you can get someone to install an uncharged system and you could charge it yourself.
When you A/C does need replacing, unless something new comes on the market, I think you'd be better off reducing the cooling needed: add shade, insure the roof is well-vented, and have appropriate insulation installed; then installing a smaller A/C system.
posted by flimflam at 1:26 PM on January 24, 2019
When you A/C does need replacing, unless something new comes on the market, I think you'd be better off reducing the cooling needed: add shade, insure the roof is well-vented, and have appropriate insulation installed; then installing a smaller A/C system.
posted by flimflam at 1:26 PM on January 24, 2019
If you go ahead and fill an AC system with a different refrigerant than it's rated for, that will definitely void the warranty. It will also mean that if you ever have to have someone come out and conduct repairs on it that involve draining and recharging the system, you will get to have an interesting conversation wherein you describe what you have done to your system and how you would like them to handle it, and try to convince them not to just throw their hands in the air and tell you to go talk to someone else.
posted by Anticipation Of A New Lover's Arrival, The at 2:07 PM on January 24, 2019
posted by Anticipation Of A New Lover's Arrival, The at 2:07 PM on January 24, 2019
Do you know any HVAC guys you trust? Could you get them to look at the system and give you advice about its expected lifespan?
We bought a 1985 house with two central a/c systems from 1994: one is in the basement for the ground floor, and one is in the attic for upstairs. A friend of my wife came over and said that, essentially, our old systems used the old refrigerant that's getting increasingly expensive for the HVAC companies to source, and our annual recharges of the leaky piles of shit would get more expensive every year -- but, crucially, a recharge is always going to cost about 1% of the cost of replacing the whole stack (air handler plus chiller, and maybe ducts)!
But anyway, he was willing to be honest about the risks and possible costs.
Sadly, last spring we ended up having to replace the upstairs air-handler -- and since the refrigerant is different, we had to replace both the air-handler and the chiller. However, they rolled the still-good chiller out behind the toolshed in case the basement's chiller fails soon, in which case we can re-use that (instead of facing another painfully-expensive engagement to swap out that whole stack).
posted by wenestvedt at 7:22 PM on January 24, 2019
We bought a 1985 house with two central a/c systems from 1994: one is in the basement for the ground floor, and one is in the attic for upstairs. A friend of my wife came over and said that, essentially, our old systems used the old refrigerant that's getting increasingly expensive for the HVAC companies to source, and our annual recharges of the leaky piles of shit would get more expensive every year -- but, crucially, a recharge is always going to cost about 1% of the cost of replacing the whole stack (air handler plus chiller, and maybe ducts)!
But anyway, he was willing to be honest about the risks and possible costs.
Sadly, last spring we ended up having to replace the upstairs air-handler -- and since the refrigerant is different, we had to replace both the air-handler and the chiller. However, they rolled the still-good chiller out behind the toolshed in case the basement's chiller fails soon, in which case we can re-use that (instead of facing another painfully-expensive engagement to swap out that whole stack).
posted by wenestvedt at 7:22 PM on January 24, 2019
Response by poster: Hey everyone, we ended up replacing the old system with a Bosch condenser and an American Standard air handler.
The old unit conked out during August. I took off the access panel and saw wires had actually burned. The AC guy told me the previous AC man had dropped in an inappropriate refrigerant that had caused the unit to draw way too much current, probably causing the burnout.
We're very happy with our new system. The Bosch condenser is apparently a pretty good deal.
posted by atchafalaya at 8:24 AM on September 24, 2019
The old unit conked out during August. I took off the access panel and saw wires had actually burned. The AC guy told me the previous AC man had dropped in an inappropriate refrigerant that had caused the unit to draw way too much current, probably causing the burnout.
We're very happy with our new system. The Bosch condenser is apparently a pretty good deal.
posted by atchafalaya at 8:24 AM on September 24, 2019
This thread is closed to new comments.
posted by Anticipation Of A New Lover's Arrival, The at 11:23 AM on January 24, 2019 [3 favorites]