Heating and cooling in St. George
In St. George, cooling is the main job. Summers are long and extremely hot, and an air conditioner that's undersized, poorly installed or neglected won't keep up.
Extreme heat
A reading of 117°F at the St. George cooperative weather station on July 10, 2021 tied Utah's all-time maximum temperature record, first set in St. George in 1985. Systems are sized for typical hot days, not record ones, so on the hottest afternoons even a good system may run constantly. That's normal. A system that can't get the house below 80°F on an ordinary summer day probably has a problem: low refrigerant, a dirty coil, a failing capacitor or leaky ducts.
Ask any contractor for a load calculation, which sizes the system to your house based on its insulation, windows, orientation and ducts. Sizing by square footage alone often misses.
Ducts in hot attics
Ducts in an attic sit in some of the hottest air in the house. Leaks and thin insulation waste a lot of cooling. Ask the contractor to inspect or test the ducts and to quote sealing and insulation separately.
Efficiency rules
Utah is in the Department of Energy's North region, where split-system central air conditioners installed on or after January 1, 2023 must be rated at least 13.4 SEER2, and split-system heat pumps at least 14.3 SEER2 and 7.5 HSPF2. In a climate with this much cooling, higher-efficiency equipment pays back faster than in milder places. Ask for an estimate of operating costs for the options you're considering.
Evaporative coolers
Some homes use evaporative (swamp) coolers. They work well in dry heat but use water, and hard water leaves scale on the pads and in the pump. Ask about maintenance and pad replacement if you have one.
Licenses
Utah law exempts remodeling and repair jobs under $7,000 from contractor licensing, but even on those jobs, work on an electrical or plumbing system must be done by a contractor holding a Utah license for that trade. Larger jobs need a contractor license in any case. Ask the contractor for their Utah license from the Division of Professional Licensing, and check it.
Comparing quotes
Ask each contractor for equipment model numbers, efficiency ratings, the load calculation, duct work, thermostat, permits and warranty terms for parts and labor. Ask when the outdoor unit will next need service, and keep its coil clean of dust.