It is hot out, turn off your A/C. (Phoenix: 2014, appliances)

[LBTRS]

Always was amazed at how hot the air being blown from my A/C unit was, never thought about the effect of so many of them running around the valley. Seems you rich guys in Scottsdale, Paradise Valley and North Phoenix need to turn your A/C temp up a bit and cool it down for the rest of us (looking at you DeroitN8V).

"Running your air-conditioner at night makes it hotter outside, and the hottest part of the Valley after the sun goes down isn't the concrete-laden city core.

A small area covering parts of Paradise Valley, north Phoenix and Scottsdale appears to have the highest overnight temperatures, about 2 degrees higher than the Valley average, according to a heat map created by Arizona State University researchers."

Running AC hard at night makes upscale Valley area hottest

[AZBradley]

Keep my t-stat at 71!!!!!!!!!!!

[LBTRS]

Originally Posted by AZBradley

Keep my t-stat at 71!!!!!!!!!!!

Yikes...that is frigged in Arizona. Your power bill must be off the charts? Mine is at 80 during the day, 78 in the evening/weekends and 76 at night.

[MotleyCrew]

Keep ours 83 during the day and night. Never liked an ice box for a house. Hope solar technology ramps up during our lifetime to see it fuel an AC and the house.

[Ponderosa]

I am a little skeptical. Aside from the fact that it is ASU students who are known more for partying than scientific inquiry, the heat being blown out by an AC is the same heat that is being gained by a structure. Other than the motor friction/heat loss, there is no net gain in heat. An AC is simply a heat "pump". Had the sun shone on the ground all day the heat would also be radiated back into the atmosphere after sundown. Whether it would be more or less than that being pumped out of the structure would depend a lot on the soil cover. PV is a lot of rock. It absorbs a lot of heat during the day and releases it much more slowly than grass or even loose soil would. I think the ASU students need to have a few more beers and think this one through some more. There may be other explanations.

[azriverfan.]

Originally Posted by LBTRS

Yikes...that is frigged in Arizona. Your power bill must be off the charts? Mine is at 80 during the day, 78 in the evening/weekends and 76 at night.

I run mine at 71 at night and my electric bills are 300-400 in the summer. Our house was designed well with good insulation and I have quality Trane units. I can't see how you sleep at 80. That is way too hot for me inside. I like 75-76 during the day. Yes, 70 at night is frigid thanks in large part to the dry air. In Florida, 71 degrees inside still feels hot due to the humidity and feels anything but crisp cold.

[LBTRS]

Originally Posted by Ponderosa

I am a little skeptical. Aside from the fact that it is ASU students who are known more for partying than scientific inquiry, the heat being blown out by an AC is the same heat that is being gained by a structure. Other than the motor friction/heat loss, there is no net gain in heat. An AC is simply a heat "pump". Had the sun shone on the ground all day the heat would also be radiated back into the atmosphere after sundown. Whether it would be more or less than that being pumped out of the structure would depend a lot on the soil cover. PV is a lot of rock. It absorbs a lot of heat during the day and releases it much more slowly than grass or even loose soil would. I think the ASU students need to have a few more beers and think this one through some more. There may be other explanations.

At first glance your post made sense but after some thought I have some questions...

Since the A/C is the largest consumer of energy in a home I'd suspect that there is a lot of heat coming from that energy usage which is being pumped into the outside air? I'm no expert but there is heat generated during the use of all that energy.

Not to mention, the A/C is cooling the inside of your home, not the outside. So the heat being put back by the coils outside the house is in addition to the heat coming from the outside of the structure (and all those rocks in Paradise Valley). There are a ton of heat generating devices (people, pets, electronics, appliances) inside the home and that heat is being transferred outside the home by the A/C.

Lastly, setting the thermostat at 80 will use less of that energy and transfer less of the inside heat to the outside then if you set your thermostat at 70.

Their conclusion seems reasonable to me. Thoughts?

[observer53]

Originally Posted by Ponderosa

I am a little skeptical. Aside from the fact that it is ASU students who are known more for partying than scientific inquiry, the heat being blown out by an AC is the same heat that is being gained by a structure. Other than the motor friction/heat loss, there is no net gain in heat. An AC is simply a heat "pump". Had the sun shone on the ground all day the heat would also be radiated back into the atmosphere after sundown. Whether it would be more or less than that being pumped out of the structure would depend a lot on the soil cover. PV is a lot of rock. It absorbs a lot of heat during the day and releases it much more slowly than grass or even loose soil would. I think the ASU students need to have a few more beers and think this one through some more. There may be other explanations.

Are you going to let your extreme dislike for ASU and your opinion that most ASU students are drunk and disorderly come into every post that mentions ASU? Why not just question the conclusion for the other reasons you state, without the superfluous, off topic, mean spirited comments?

[LBTRS]

Originally Posted by azriverfan.

I run mine at 71 at night and my electric bills are 300-400 in the summer. Our house was designed well with good insulation and I have quality Trane units. I can't see how you sleep at 80. That is way too hot for me inside. I like 75-76 during the day. Yes, 70 at night is frigid thanks in large part to the dry air. In Florida, 71 degrees inside still feels hot due to the humidity and feels anything but crisp cold.

I can't sleep at 80, that is why it is at 76 at night. I can sleep at 76. 80 during the day when it is really hot outside.

Even 76 at night wasn't comfortable when we first moved here, however, it didn't take long until we acclimated and it is now comfortable. We even use covers on the bed.

[43north87west]

I think it has a lot more to do with local geology than anything else. But a study that claimed "local geology makes valley area hottest at night" wouldn't make much of a news story.