The AC runs all day and the house stays warm
Denver summers are shorter than a hot-climate city, and the cooling still falls behind. Thin air and a blocked coil are the usual reasons.
July is still a cooling month
Afternoon highs sit in the upper 80s and low 90s, and a heat wave goes past that. The cooling season is only a few months, which is why an air conditioner often lasts longer here than in Phoenix. It can still lose the afternoon.
The air is dry, so the system spends almost all of its work lowering temperature, not pulling humidity out of the house. A warm house is a temperature problem, not a dehumidifier problem.
A mile of elevation takes a slice of capacity
Cooling capacity drops about 1 percent for every 1,000 feet of elevation. At 5,280 feet that is about 5 percent under the nameplate. The outdoor coil dumps heat into thinner air, so the same unit works harder for each hour it runs.
Installing a bigger unit to paper over that often short-cycles the compressor. The right size is a load that already accounts for elevation, not the next size up.
What makes a good system look weak
A packed filter, closed supply vents, and cottonwood on the outdoor coil. Cottonwood season around April through June will mat the fins until the unit cannot reject heat. Two feet of clearance around the outdoor unit, and a filter that still lets air through, are the checks that belong to the house.
Ice on the line, a breaker that trips, or air that is barely cool is a visit. We say whether it is a capacitor, a coil, the charge, or a system that is done. Written price before anyone is scheduled. (564) 888-5527.