AC Repair in Superior, Colorado

An air conditioner in Superior was not designed to hold an indoor setpoint on the hottest afternoon of the year. Residential equipment is sized against a design condition that the local climate exceeds a small percentage of hours each season, and on those hours a correctly working system runs continuously and still loses ground. Knowing that distinction is what separates a real fault from physics. MoJo Home Services covers this Boulder County town of 12,980 at 5,495 feet: 720-807-4050.

What outdoor temperature was a Superior system sized for?

Not the record high. Residential load calculations use a design dry-bulb temperature that this part of the Front Range exceeds only a small fraction of cooling-season hours, a figure that sits closer to 90 degrees than to 100. Equipment is then selected to hold an indoor design temperature, commonly around 75 degrees, at that outdoor condition. Above the design temperature, the load rises past the capacity that was deliberately purchased, and the system falls behind. That behaviour is the sizing method working as intended, not equipment failing.

How do I tell a system falling behind from one that is broken?

By the temperature drop across the indoor coil. Measure the return air temperature and the supply air temperature at the plenum with the system running steadily. In the dry air of Boulder County a healthy split generally lands somewhere in the high teens to low twenties in degrees. If the split is right and the run time is continuous, the system is delivering its capacity and the load has simply outgrown it for the afternoon. If the split is narrow, capacity is genuinely missing and the cause is airflow, charge, or heat rejection at the condenser.

Why is a bigger air conditioner not the answer in Superior?

Because equipment sized to the rare extreme runs badly during the many ordinary days. Oversized cooling satisfies the thermostat quickly, shuts down, and repeats, and short cycling wears contactors and compressors faster than steady operation. It also removes less moisture, since dehumidification happens over the length of a run cycle rather than at start-up. The right correction for a Superior house that loses ground at peak is almost always a load reduction or an airflow fix, evaluated through a proper load calculation and equipment selection rather than a jump to the next size.

What does 5,495 feet do to the sizing math?

It changes the air the equipment is rated on. Superior air is about 15.1% less dense than sea-level air, so a coil needs roughly 471 CFM per ton to move the mass that 400 CFM per ton moves at sea level, and the sensible heat formula used in load work has to be corrected for the same reason. Separately, gas-fired equipment in Superior derates 14.0% under the NFPA 54 convention. Rated capacity printed on a box is a sea-level number in both directions.

Does Boulder County change anything about the work?

It changes which authority has jurisdiction over replacement work. Superior is the only Boulder County community in this group of pages, alongside our coverage of Lafayette, Broomfield and the Eldorado Springs area, and permitting requirements for equipment replacement are set locally rather than metro-wide. We confirm the authority for the specific address before replacement work rather than assuming the rules that apply in Adams or Douglas County apply here.

What does a Superior cooling diagnostic measure?

Return and supply temperatures and the resulting split, total external static pressure and delivered airflow, superheat and subcooling read together, condenser approach against the air entering the outdoor coil, capacitor microfarads, and compressor and fan amp draw against the nameplate ratings. Those numbers answer the question this page opens with: is capacity missing, or is the load simply larger than the equipment was ever bought to handle? Those two situations get very different recommendations.

Does running the fan continuously help on a hot Superior afternoon?

It helps with even temperatures between rooms and hurts nothing much in this climate, but it does not add capacity. With the fan set to on rather than auto, air keeps moving after the compressor stops, so registers blow room-temperature air and the house can feel worse even though the equipment is fine. In the humid parts of the country continuous fan operation also re-evaporates moisture off the coil back into the house; in Boulder County air that effect is small. If the aim is to keep an upstairs room closer to the rest of the house, continuous circulation is a reasonable tool. If the aim is more cooling, it is not one.

Boulder County neighbours

The same routes cover Broomfield to the east, Lafayette north, and Eldorado Springs up against the foothills.

Where else we work

Nearby and on the same schedule: AC repair in Broomfield, AC repair in Lafayette, AC repair in Eldorado Springs, AC repair in Thornton.

For the other half of the system, furnace repair in Superior.

More on the service itself: AC repair.