[OmegaSupreme]

I would look into radiant barriers and attic fans

I'm getting mine installed next year before summer kicks in if I'm still at the same house

With temps as they are, I regret not getting this done in April when I was contemplating it

[equid0x]

I did some testing with this during May this year in my own home because I was considering switching to TOU rates. I have a remotely controllable thermostat that logs the amount of time the unit has spent turned on. I believe my home is fairly tight, with Low-E windows, radiant barrier, blinds that I keep shut all day and a Pergola on the East side of the house that blocks sun from the sliding glass doors to the patio in the AM. I also have an insulated garage door.

I found that if I precooled the house to 68 before 7am, and then switch the AC up to 85, that it was not kicking on until roughly 6pm. This was the case even when we had a couple of days where it got up to 105. I did think that 68 was a bit on the cold side to wake up to in the morning for my taste.

I did an analysis and found that the TOU-A plan would likely save me about $150/yr over the long term. I found that the TOU-B plan would have been more expensive no matter what. I would also point out that there may be more potential savings if I switched the pool pump to run during the nighttime to take advantage of the TOU rates. I estimate that the pump costs me about $50/mth to run under the standard rate plan. I think if I were spending significant amounts of time away from the home during the peak rate hours that I would likely switch to the TOU-A plan to save money.

My thermostat has the ability to respond to geofences via the smart phone. I have been experimenting with having the system automatically kick up to 85 when I am outside the geofenced area, in lieu of running on a time schedule, and then kicking the AC down to 77 when its time to sleep, with a timer that automatically sets the temp back to 82 around 3am. So far, this seems to be working well, but probably not as cheap as precooling on TOU-A. It is very convenient though, and I am not lacking in comfort.

[WestieJeff]

I'm surprised your savings would only be $150/yr. Under TOU-A (I've been on for two full years now) my bill went from around $155/mo to $95/mo annualized. I work normal business hours so am away most of the TOU time. I do have a pool pump which shifts off-peak to help.

Originally Posted by equid0x

I did an analysis and found that the TOU-A plan would likely save me about $150/yr over the long term. I found that the TOU-B plan would have been more expensive no matter what. I would also point out that there may be more potential savings if I switched the pool pump to run during the nighttime to take advantage of the TOU rates. I estimate that the pump costs me about $50/mth to run under the standard rate plan. I think if I were spending significant amounts of time away from the home during the peak rate hours that I would likely switch to the TOU-A plan to save money.

My thermostat has the ability to respond to geofences via the smart phone. I have been experimenting with having the system automatically kick up to 85 when I am outside the geofenced area, in lieu of running on a time schedule, and then kicking the AC down to 77 when its time to sleep, with a timer that automatically sets the temp back to 82 around 3am. So far, this seems to be working well, but probably not as cheap as precooling on TOU-A. It is very convenient though, and I am not lacking in comfort.

[airics]

i'm on TOU also and i love it..... I crank the ac down to 73 from 715pm to 12 Noon the following day. Its set at 85 from 12pm-7pm. My bills have been great.. looks like this month will be $125. I couldn't believe how cheap it was off season $35-$60. I also have a variable speed pool pump running from 6am till Noon. My house is 3 story 2700sf

[OmegaSupreme]

Originally Posted by airics

i'm on TOU also and i love it..... I crank the ac down to 73 from 715pm to 12 Noon the following day. Its set at 85 from 12pm-7pm. My bills have been great.. looks like this month will be $125. I couldn't believe how cheap it was off season $35-$60. I also have a variable speed pool pump running from 6am till Noon. My house is 3 story 2700sf

Are you on tou a? It should be 1pm-7pm peak

[SportyandMisty]

Originally Posted by MediocreButArrogant

You mean the energy spent just getting the inside coil cooled off when it starts?

That, but also the initial surge in energy consumed just to start the electric motors and pumps.

[OmegaSupreme]

Originally Posted by SportyandMisty

That, but also the initial surge in energy consumed just to start the electric motors and pumps.

i'm pretty sure that's irrelevant in the grand scheme of things, i could be wrong.

a/c consumes 3k-4k watts when it is running, which is a lot. this is a constant pull with most of the electricity being consumed by the compressor

[equid0x]

Originally Posted by OmegaSupreme

i'm pretty sure that's irrelevant in the grand scheme of things, i could be wrong.

a/c consumes 3k-4k watts when it is running, which is a lot. this is a constant pull with most of the electricity being consumed by the compressor

I agree with OmegaSupreme. There is a large inrush current but this is only transient. My unit also consumes approx 4KW/hr while running. I have a 5 ton unit.

[hannaranch]

I run mine 24/7 at about 74 degrees. I live in a condo on the first floor with about 1,024 sf of space. I find that my air is only running for about 5 to 10 minutes at a time.

[equid0x]

Originally Posted by hannaranch

I run mine 24/7 at about 74 degrees. I live in a condo on the first floor with about 1,024 sf of space. I find that my air is only running for about 5 to 10 minutes at a time.

If it's maintaining the temp properly in this weather and still cycling that often it's probably oversized. I would downsize the unit when this one dies. A compressor with half the output consumes only 1/8 the power. Should result in a substantial bill reduction even if it runs more. Properly sized, an AC unit should run full time under peak load.

It is always cheaper to run a smaller motor longer if it can still keep up with the load while doing so.