YSK because the first hot spell is when most people discover their AC unit is broken.
Several years ago I waited to turn on my AC. This is how I found out about one of the busiest times for repairmen and had to sweat for two weeks. Now I do a test run a couple of weeks before it heats up. Same goes for the furnace at the end of Autumn.
Edit to add: YSK line (Rule 2)
Joke’s on you, in Texas you always need it
My relatives in south TX are melting. I hope where you are isn’t as bad.
Meh, 104 degrees feels like 117. It’s…bearable but not enjoyable. What I dislike is it still being 92 at 9pm.
As someone from Upper Michigan, that does not sound bearable to me.
Then again, 0 degrees with -15 windchill probably sounds more bearable to me than to you.Floridian here. Anything below 20°F sounds like penguins, and there is no discernable difference between temperatures (eg 15°F ≈ -42°F/C = 🐧🐧).
Idk if I can do a good job, but for me, 10-20 degrees is average winter temp. Nothing to be concerned about: just my winter coat and thin gloves.
0-10 degrees is starting to get cool. If I’m outside for a prolonged period of time I’ll add a hat and switch to my thicker gloves.
-10-0 degrees is cold. That’s the period where breathing through your nose gets crispy and deep breaths make you cough. I always have a hat and good gloves at this range. If I need to be outside for a while, I use flannel lined jeans. I also make sure to use my actual winter boots.
-20 to -10 degrees is rare, but does happen. You really shouldn’t be outside at those temps, but I’ve done it anyway. Any breeze at that temperature is dangerous. A facemask of some kind is strongly recommended if you need to be out for any length of time.
Coldest I’ve personally experienced was -25 degrees. That was winter 2013-14. There’s nothing quite like experiencing that level of cold. I left a university building to go to my jeep with a bottle of powerade in my backpack. When I got to my jeep it had turned into a slushie.
All these temps are absolute by the way; not windchill.
I think it’s generally good policy to run ACs every month or so.
I have window units. You think I’m going to leave those in during winter? I like my heat inside my house, thank you very much.
I’m just saying it’s better for the units to run once in a while, and to test them to know they are still working. I guess you could technically run a window unit for a few min when it isn’t in the window but watch out for condensation drain.
Why? What purpose does this serve? This is a real question, not a snarky comment. What do I not know?
Refrigeration tech here. Don’t run your home AC in the winter unless it was specifically designed for that. I think the person you’re responding too was assuming that because that’s what you’re supposed to do for cars that you should do it for your home too.
In cars the AC compressor runs off the belts so there is a shaft seal that can dry out and crack if the system is not run every so often. On residential AC systems the compressor is run by an electric motor that is sealed inside the compressor housing. There is no shaft seal that can fail. Running your home AC in the winter can actually damage it if your system wasn’t designed for cold weather running. When it’s cold outside liquid refrigerant will tend to condense inside the compressor. When the compressor starts in those situations it will immediately suck in and try to compress that liquid refrigerant. Unless you’re a physicist, liquids are incompressable. So you now have your compressor trying to compress something that can’t be compressed. This is not good for the compressor to put it lightly. The best case scenario here is the compressor manages to force the liquid refrigerant out adding a whole lot of premature wear in the process. The worst case scenario is that something inside the compressor goes pop and it dies.
On systems designed to run in cold weather there will be a little band heater on the compressor to keep it warm and prevent refrigerant from condensing inside it. However that is not the norm for residential AC just because most residential AC systems don’t need it and it would just be a waste of electricity.
Most machinery lasts longer when you run it every month or so at least. For an AC unit there is lubricant in the refrigerant, so circulating the refrigerant once in a while keeps the seals in good condition. It would also keep the moving parts of things like fans from corroding and seizing up.
For vehicles, running the them occasionally circulates the fluids like oil and antifreeze. The oil keeps the moving parts of the engine coated and doesn’t allow things like condensation to rust the internal parts.
Same reason why if you have part time 4WD in a vehicle you should put upwards of 10 miles per month with 4WD engaged (just try to keep it to straight roads). Check your owners manual first, but every 4WD vehicle I’ve owned has recommended it.
This is definitely good advice for vehicle AC because like you said, it keeps the compressor seals in good shape. However it isn’t as important for residential AC systems because they use fully hermitic compressors. There is no shaft seal that can fail. Depending on your outdoor temps, running your home AC in the winter can actually be very bad for it.
When it’s cold outside liquid refrigerant will tend to settle in the compressor crank case that means when that compressor starts up it will immediately suck in and try to compress that incompressable liquid refrigerant. Depending on the compressor type this will drastically reduce it’s lifespan or just straight up kill it. On systems designed to be used in cold weather there will be a crank case heater on the compressor to boil off any liquid refrigerant in the crank case. But if your system wasn’t built with cold weather running in mind then it won’t have one of those.
Today I Learned, don’t run a house AC when it’s cold.
Hello there. Please add a “Why YSK:” to your post’s body text. :)
If you have a portable AC unit don’t forget to clean the air filter(s) before you start using it for the season!
Relatedly: there are HUGE tax credits for heat pumps right now; I’m actually paying several thousand dollars less for a new heat pump than I would have for a new central AC. (Installed as a two stage system, so I can still use my regular boiler when it gets cold)
So if anybody else is up for a replacement you should definitely take a look at any federal + state + local credits you might get for going that route.
Having a boiler + heat pump would be a Hybrid system. A 2-stage heat pump typically refers to the capability for the heat pump to run at lower power (such as 70% max) or full power, to try and prevent thrashing on slightly warm days, while keeping capacity available for hot days.
I wish i knew this back in November…
For heating or are you one of our friends in the southern hemisphere?
I am from the southern hemisphere
We have our Aircon cleaned around March or April because when everyone turns them on and realises how badly they smell in July all the cleaning services are busy.
YMMV But another fun AirCon fact*.
A few years ago we switched from running the air con hard at 20°C or so when we got home, having it turn off automatically late at night, running it hard in the morning and turning it off when we went out…
To…
setting it at a supposedly “high” setting of 27°C and leaving it on 24/7 (July to September)
The running cost was the same and it was very comfortable coming home to an already cool dry environment. We never felt the need to lower the temperature either. It was lovely.
*“fact”. I’m sure the condition of your home insulation, outside temperature and conditions, draftiness of windows and doors etc all play a role.
As someone who lives where it’s hot all year round, this took me a second to understand.
We were told we needed the unit replaced because it needed Freon that was no longer available.
Somehow my dad has a guy who came to the house and filled it up and left very discreetly.
It was probably running R-22 which you can still get but it isn’t manufactured anymore. It’s ozone depleting so all production and import of the stuff was completely banned in 2020 and it has been in the process of being slowly phased out since 2004. The only source for it is stuff recovered out of other systems or any existing stocks which are running out very quickly. That means it gets more expensive every year. Now a days most HVAC companies will just replace those systems rather than fixing them for that reason.
Also it’s become very expensive compared to the new stuff for this reason. Like over 10x more expensive per pound.
Yup, what we learned here. Our air is working fine as we did get a new one not too long ago. So need it during the summer time around here in the midwest.
This is true of car ACs as well. Many modern cars with climate control do use the AC to some degree in defrosting, but some use periodically will keep seals from drying out and causing leaks.
You should actually be getting your annual routine maintenance as recommended by the manufacturer.
The people that installed my new HVAC this time last year called me just this morning … do you work for them?
Second this. Keeps the unit in good order, you find out about issues before they become major problems, and it’s usually fairly cheap like 50 bucks. The downside is it’s a good opportunity for an unscrupulous tech to overplay some minor issue to try convince you to upgrade.
Could you please add a “Why YSK:” to the body of your post? It’s rule #2.
I thought I edited that in when I saw the first comment about it. I’ll go back and check. Thanks.
