Another A.C. Question.

[FreeBird236]

My thermostat has the ability to have the temperature differential settings in half degree increments, from half a degree to one and a half degrees. My question is: On an older unit (18 year old Goodman) is it better to run shorter time more often, or a longer time less often? The unit seems to be fine, just trying to make it easier on the unit. Usually have it at one degree, but this heat wave, have been noticing it running quite a bit longer. Thanks.

 

[TimeBandit]

It's HOT. The A/C needs to run a loooong time to knock down the temps in our house.

1/2 degree? you mean set it at 75.5 instead of 75 ??

I'm not seeing how that would matter, it will climb 1/2 degree in a short amount of time then have to keep running to keep it there.

Any decrease in run time will be short lived.

 

[CLdrinker]

You don’t want it to short cycle. The unit kicking on is what draws the power and is harder on the unit.

The less on and off the better.

 

[satellitemike]

This ^^^^^^^

 

[Bobby V]

18 years on a Goodman? That’s great. My Goodman only lasted 5 years before Carey replaced it.

 

[Badchoices03]

18 years on a Goodman? That’s great. My Goodman only lasted 5 years before Carey replaced it.

I just replaced my Goodman after 15 years....mostly because it was R22 and its hard to come by now...

 

[Mr. C]

If I’m understanding you correctly.
Mine I think is 1 degree plus/ minus.
Meaning if my AC is set to 73. It will run until the thermostat hits 72. Shut off. And then start up again at 74. Then repeat itself.
Are you saying you can set yours at 1/2 degree plus/ minus. ??

 

[FreeBird236]

It's HOT. The A/C needs to run a loooong time to knock down the temps in our house.

1/2 degree? you mean set it at 75.5 instead of 75 ??

I'm not seeing how that would matter, it will climb 1/2 degree in a short amount of time then have to keep running to keep it there.

Any decrease in run time will be short lived.

Not really setting at half degrees, just that it won't come on until it's, half, one, or one and a half degrees warmer. So, one way it runs shorter but more often, and the other way it runs longer but less often.

 

[FreeBird236]

If I’m understanding you correctly.
Mine I think is 1 degree plus/ minus.
Meaning if my AC is set to 73. It will run until the thermostat hits 72. Shut off. And then start up again at 74. Then repeat itself.
Are you saying you can set yours at 1/2 degree plus/ minus. ??

Yes.

 

[FreeBird236]

I just replaced my Goodman after 15 years....mostly because it was R22 and its hard to come by now...

I've been tempted to, but a couple of techs have said just let it go until it fails and make a decision on repair or replace at that time.

 

[FreeBird236]

You don’t want it to short cycle. The unit kicking on is what draws the power and is harder on the unit.

The less on and off the better.

I've always thought setting the differential to at least 1 degree so it's not always cycling would be best, but on the news, they were recommending not setting the thermostat up when you leave the house, because when you return home, it obviously needs to run longer to catch up and it's hard on the unit. so, I started to question my thinking.

 

[Dalton]

Starting is when there’s most strain on the unit

 

[azsunfun]

Raise temp no more than 4 degrees when not home, less catch up time. There is also something that has not cought on called super cooling, drop temp in house as low as can be tolerated at nite, theory being all interior contents walls, furniture will drop to that low temp keeping air off longer in the morning to afternoon. I won't even try I'm a pussy when it comes to cold.

 

[DarkHorseRacing]

Raise temp no more than 4 degrees when not home, less catch up time. There is also something that has not cought on called super cooling, drop temp in house as low as can be tolerated at nite, theory being all interior contents walls, furniture will drop to that low temp keeping air off longer in the morning to afternoon. I won't even try I'm a pussy when it comes to cold.

I do this in Arrowhead because I dont have A/C. I use fans and let them run all night trying to cold soak the house so that it starts at a lower temp in the morning and doesn’t heat up as much throughout the day.

House still gets up to about 82 though when I get home from work. I’ve also finally got shades or blinds in all the windows and leave everything closed so the heat from the crappy dual pane windows doesn’t heat up the house. Helps in the winter too holding heat in.

I’m getting a portable tower AC unit to do room cooling and just exhaust it out a nearby window to try and cool rooms we are in the most when we are home. The house does ok with short heat waves but the extended ones it’s harder to cool the house down as the morning lows don’t drop as much.

 

[FreeBird236]

Thanks for all the replies. I think I'll leave it at 1* differential, might even try 1.5*.

 

[TrollerDave]

Not really setting at half degrees, just that it won't come on until it's, half, one, or one and a half degrees warmer. So, one way it runs shorter but more often, and the other way it runs longer but less often.

Like CLdrinker said, the start up is HARD on a unit especially in HOT weather.
Is this Havasu?
Best thing is to make sure it is well maintained: clean coils, tight electrical connections, good contacts on the contactor.
A well insulated house is important. It will help keep outside weather from infiltrating to the inside conditioned space. The better insulated, the less the A/C runs and cycles.

 

[CLdrinker]

I've always thought setting the differential to at least 1 degree so it's not always cycling would be best, but on the news, they were recommending not setting the thermostat up when you leave the house, because when you return home, it obviously needs to run longer to catch up and it's hard on the unit. so, I started to question my thinking.

1 degree difference means you set it at 75 it run until it hits 75 then shuts off. Soon as it hits 76 it kicks back on.

Running long periods is much better than on off on off.

Go do the same with your car or boat. How long is that starter going to last?

 

[Good Stuff]

1 degree difference means you set it at 75 it run until it hits 75 then shuts off. Soon as it hits 76 it kicks back on.

Running long periods is much better than on off on off.

Go do the same with your car or boat. How long is that starter going to last?

I always understood it as running to 74 before off and then 76 back on with 1* differential and set to 75. Pretty sure that’s how my Nest thermostat runs at home but maybe it’s a 2* differential.

 

[Riverbound]

longer run times are better on equipment and comfort in home.

 

[FreeBird236]

Like CLdrinker said, the start up is HARD on a unit especially in HOT weather.
Is this Havasu?
Best thing is to make sure it is well maintained: clean coils, tight electrical connections, good contacts on the contactor.
A well insulated house is important. It will help keep outside weather from infiltrating to the inside conditioned space. The better insulated, the less the A/C runs and cycles.

Yes, in Havasu. Unit has been serviced, Insulation is top notch, but at 118* +-, you start noticing more cycling. Thanks.

 

[FreeBird236]

longer run times are better on equipment and comfort in home.

Thanks

 

[Ultra...Good]

I've always thought setting the differential to at least 1 degree so it's not always cycling would be best, but on the news, they were recommending not setting the thermostat up when you leave the house, because when you return home, it obviously needs to run longer to catch up and it's hard on the unit. so, I started to question my thinking.

Believe everything you hear on the news?

I run my a/c however the temp calls for it. I do set the temp up 4-5 when I leave and run it a little cooler when home and cooler when sleeping. I also run a de-humidifier and fans. Have good windows, coverings, and insulation.

I have a welder that has a 40% duty cycle. Meant to run for 4 minutes and be on but not welding for 6. I have a water pump that is a continuous duty and that is better to run constantly compared to stopping and restarting frequently. Not sure what the a/c is rated at but it is from 1995 and has never needed any service or freon added. Make sure the coils are clean and run it.