Why not just turn the AC off when I leave?
In Arizona the house can heat up quickly, and the AC then has to run for a long stretch to pull it back down. Heat can also stress electronics, pets, plants and finishes, so a modest setback is usually the better choice.
Attic heat soaks into the structure all day. By the time you come home, a house with the AC off can be uncomfortable for hours.
Humidity also rises during monsoon season, and an uncooled house can feel sticky and invite moisture problems.
How big should the temperature setback be?
A few degrees above your normal setting is a reasonable starting point for most homes. Larger setbacks save less than people expect in extreme heat, and they can leave the system struggling to catch up when you return. Start small and adjust after a few days.
Every house behaves differently. Insulation, window coverings, ceiling height and shade all affect how fast the temperature climbs and how quickly it recovers.
Try one setting for a week, note how long recovery takes, and adjust. Your own experience beats general rules.
Is the advice different for a heat pump?
Yes. Heat pumps do best with steady settings, because big swings in heating mode can trigger the electric backup heat, which uses more power. Use small setbacks and let the heat pump recover gradually. Ask a technician if you are unsure which settings your system needs.
Some smart thermostats have heat pump settings that limit backup heat. Check that your thermostat is configured for a heat pump, not a conventional furnace.
In summer, a heat pump behaves like any air conditioner, so the cooling advice above still applies.
Can a smart or programmable thermostat help?
Yes. A programmable or smart thermostat can raise the setting while you are out and start cooling before you return, so you come home to a comfortable house without paying to cool an empty one all day. Features vary by model, so match the thermostat to your system.
Set a schedule that matches how your household really lives. A schedule that fights your routine just gets overridden.
Remote control and geofencing features can adjust the setting when you leave unexpectedly. These need a reliable Wi-Fi connection and correct thermostat wiring.
What if I am away for several days?
For a trip, choose a moderate setting rather than shutting the system off. A house left to heat up in summer can damage items inside, and in winter a very low setting is unnecessary in most of the valley. Your comfort and home protection both matter.
Replace the air filter before a long trip and make sure the condensate drain is clear. Those simple steps prevent problems while you are gone.
If your system acts up, Vortech Air-Conditioning & Electrical is open 24 hours per our Google profile. Use the call button on this page to reach the team.
More questions: Thermostats: 12 Most Asked Questions Answered