Spending thousands on a new air conditioner and still ending up with hot upstairs bedrooms or power bills that jump every month is more common in Teton County than most people realize. Many homeowners assume they just had bad luck with the equipment or that our mountain weather is too much for any system. In reality, those frustrating results usually start long before the thermostat is turned on.
In Teton County, Eastern Idaho, and Western Wyoming, AC systems work under conditions that are very different from what manufacturers use in their brochures. Higher elevation, big swings between daytime and nighttime temperatures, long winters, and homes with lofts and big windows all put more pressure on how the system is designed and installed. When installers cut corners or treat your home like a generic floor plan, comfort problems and breakdowns are almost guaranteed.
At Teton Heating & Cooling, we have spent 20 years installing and repairing HVAC systems in Eastern Idaho and Western Wyoming, including Teton County. Many of our summer service calls involve tracking problems back to installation choices, not defective equipment. In this guide, we walk through the AC installation mistakes we see most often in Teton County homes, explain what is really going on inside your system, and show you how to avoid those issues before you sign an installation contract.
Why AC Installation Mistakes Hit Harder in Teton County
Teton County sits at a higher elevation than many parts of the country, and that alone changes how an air conditioner behaves. At higher altitudes, the air is thinner and holds less heat, so the same piece of equipment can deliver less cooling than its nameplate rating suggests. Manufacturers typically test and rate systems at or near sea level and under specific lab conditions. When that same unit is installed in Jackson or surrounding communities, its real output is lower, which means there is less room for error if the system is sized or installed poorly.
Our climate also brings big swings between daytime and nighttime temperatures. A home in Victor or Driggs might see hot sun and warm afternoons, then much cooler nights. That kind of pattern changes how often your AC starts, how long it runs, and how quickly the indoor temperature moves around. If a system is oversized or the thermostat is in the wrong place, you get more short cycles, more wear and tear, and rooms that never quite settle into a comfortable, even temperature.
Local home designs add another layer of complexity. Many Teton County houses have vaulted ceilings, open lofts, large south or west facing windows, and multi-level layouts. All of that affects how heat moves through the building and where hot and cold spots show up. A one-size-fits-all installation approach that ignores those details usually leads to upstairs bedrooms that are too warm at night, loft spaces that feel stuffy, and basements that feel over-cooled. After working in this region for two decades, we have seen how small design decisions magnify into big comfort issues when the system does not match the home and the local environment.
Mistake 1: Sizing Your AC by Square Footage or Old Equipment
One of the most common AC installation mistakes in Teton County starts before any tools come out of the truck. Many systems are sized based on rough rules of thumb, such as a certain number of tons per square foot, or by simply matching whatever size unit was already there. That approach ignores insulation levels, window area, ceiling height, orientation to the sun, air leakage, and how the home is actually used. In our region, where altitude already reduces capacity, this kind of guesswork can push a system too far in either direction.
Oversizing is a problem we see often in newer, tighter homes. A system that is too big for the actual cooling load can bring the temperature down near the thermostat very quickly, then shut off. The rest of the home, especially rooms farther from the thermostat or on upper levels, does not have time to catch up. The system then starts again shortly after, which is called short cycling. Short cycling increases wear on compressors and fan motors, reduces the unit’s ability to manage humidity, and often leaves you with muggy air and uneven temperatures even though the system appears powerful on paper.
Undersizing creates a different set of frustrations. An undersized AC in Teton County may run almost nonstop on the hottest afternoons, struggling to reach the setpoint on the thermostat. The equipment spends much of its life at or near full output, which is hard on components and can shorten its lifespan. You may notice that certain rooms never feel cool enough, or that the system finally catches up only late at night when outdoor temperatures drop. In both oversizing and undersizing cases, homeowners often blame the brand or think “that is just how this house cools,” when the real issue is how the capacity was chosen.
The right way to size an AC is to perform a proper load calculation. In simple terms, this means measuring and assessing the home: square footage by room, window sizes and directions, insulation levels, air leakage, number of occupants, and how spaces connect. This type of calculation estimates how much heat the house gains on a design summer day, and how much cooling is required to offset it. At Teton Heating & Cooling, we base our recommendations on a careful in-home assessment rather than guesswork. That is one of the main ways we avoid the AC installation mistakes that lead to short cycling, nonstop running, and comfort complaints in Teton County homes.
Mistake 2: Ignoring Ductwork and Airflow When Replacing the AC
Another AC installation mistake we see throughout Eastern Idaho and Western Wyoming happens when a contractor swaps out equipment and leaves the ductwork untouched. The ducts are the lungs of your system. If they were never sized correctly, or if they are leaky or restricted, simply bolting a new condenser and coil to them will not fix underlying airflow problems. In fact, newer high efficiency equipment can be more sensitive to poor duct design and may perform worse than the old unit if the ducts are not addressed.
Undersized or poorly laid out ducts create high static pressure. You can think of static pressure as the resistance the blower fan has to push against to move air through the system. If the ducts are too small, have too many tight turns, or are pinched and kinked, the blower has to work much harder to deliver the same amount of air. Homeowners notice this as loud whooshing at vents, whistling returns, or some rooms with barely any airflow. Over time, high static pressure can cause blower motors to fail early and can make the system noisy and inefficient.
Airflow problems also lead to comfort issues that are very familiar in Teton County homes. Long duct runs to bonus rooms over garages, or to upper floors, may leave those spaces weak on airflow and always lagging behind the rest of the house. Leaky ducts in crawlspaces or attics waste cooled air and let in dust and outdoor air. Coils that do not get enough airflow can get too cold and start to freeze, which reduces cooling even further and stresses the compressor. These are classic AC installation mistakes that many homeowners never hear about, because so much attention is put on equipment efficiency ratings rather than the ductwork that supports them.
During our inspections and installations, we pay close attention to existing ductwork and return air paths. We look at the size and number of supply runs, the condition of flexible ducts, the location and size of returns, and any obvious bottlenecks. In many Teton County homes, small changes, such as adding a return in a key area or correcting a restricted run, can make a big difference. Our recommendations are tailored to the home so that when we install or replace your AC, it actually has the airflow it needs to perform as designed, rather than fighting against undersized or neglected ducts.
Mistake 3: Poor Outdoor Unit Placement in Our Mountain Climate
Where the outdoor condenser sits on your property is not just a matter of where it fits. In Teton County’s mountain climate, poor placement is one of the AC installation mistakes that can show up fast in higher energy use, louder operation, and reliability issues. The outdoor unit’s job is to move heat from inside your home into the outside air. It needs plenty of clear, relatively cooler air around it to do that efficiently.
When a unit is installed in direct afternoon sun, tucked into a tight corner, or surrounded by shrubs and fences, the air around it heats up and recirculates. The condenser has to work harder to push heat into already warm air, which raises operating pressures and reduces efficiency. Over time, that extra strain can shorten compressor life. Homeowners notice this as a unit that seems unusually loud, runs longer than expected on hot afternoons, or struggles more on days with intense sun even when the indoor settings have not changed.
Our winter conditions add another layer. Snow drifts, roof shedding, and strong winds can bury or damage a condenser that sits too low or too close to rooflines. We have seen units in Jackson, Wilson, and nearby areas disappear under drifts or take direct hits from sliding snow and ice. When this happens, the unit can be damaged, and repeated snow and ice exposure can shorten its life. Clearance around the unit also matters for service access and for keeping coils clean and free of debris.
When we plan outdoor placement, we look at more than just the shortest line set. We pay attention to how snow falls and drifts on your property, where the sun hits hardest in the afternoon, how wind tends to blow, and how close neighbors and windows are for noise considerations. By choosing a location with good airflow, reasonable shade, and protection from snow and ice, we help your AC maintain proper heat rejection and run times. That reduces the chance that placement will become an invisible, expensive AC installation mistake down the road.
Mistake 4: Thermostat and Indoor Unit Locations That Fight Your Home’s Layout
The thermostat is the brain of your cooling system, and the indoor unit and returns are its circulatory system. If they are located in the wrong spots, your AC will constantly misread what is happening in the home. In Teton County’s multi-level and open homes, this is more than a small annoyance. It can be the main reason some rooms are never comfortable, no matter what you set on the thermostat.
We often see thermostats placed for convenience rather than performance. Examples include a thermostat in direct sunlight, near a supply vent, above a return grille, or in a hallway that nobody occupies. In those cases, the thermostat may think the home is hotter or cooler than occupied rooms actually feel. The system shuts off because the hallway hit the setpoint, while bedrooms or living spaces lag behind. Or the thermostat sees sun and keeps the system running longer than needed, overcooling other areas.
Indoor unit and return air locations have similar consequences. If the main return is in a hallway and there is little return air from upstairs, the system can struggle to pull warm air off the upper level, leaving those rooms stuffy. Lofts and vaulted spaces in Teton County homes can trap warm air that never gets properly mixed and returned to the system. As a result, the AC cycles based on what it “sees” at the thermostat and return, not on what you feel in bedrooms, offices, or gathering spaces.
When we evaluate or design a system, we look closely at how your family uses the home. We ask which rooms matter most for comfort, when they are occupied, and where the worst hot and cold spots are today. That information shapes our recommendations for thermostat location, return placement, and any needed changes to improve air circulation. By putting the controls and air paths where they match real life, we help your AC system work with your home’s layout instead of fighting against it.
Mistake 5: Skipping Critical Setup Steps on Installation Day
Even if the right equipment is chosen and placed correctly, an AC installation can still fall short if the startup and setup steps are rushed. Some of the most serious AC installation mistakes in Teton County happen on installation day, where they are invisible to homeowners but have long term effects on performance and reliability. These include poor evacuation of the refrigerant lines, incorrect refrigerant charge, and incomplete testing before the crew leaves.
Before refrigerant is added, the copper lines that connect the indoor and outdoor units need to be evacuated. That process removes air and moisture from the system. If this step is skipped or rushed, moisture and non-condensable gases stay inside. Over time, that can contribute to internal corrosion, form acids in the system, and reduce heat transfer inside the coils. The result is lower efficiency, hotter operating temperatures for the compressor, and a higher risk of early failure.
Setting the correct refrigerant charge is just as important. Too much refrigerant raises system pressures and can reduce efficiency. Too little refrigerant can lead to poor cooling and may cause the indoor coil to freeze. In both cases, the symptoms from the homeowner’s perspective are similar: the system never quite feels right, energy use is higher than expected, and there may be odd noises or frequent cycling. These issues can show up in the first season or two, but because the equipment is new, people often do not suspect that installation steps are to blame.
Proper commissioning also includes checking airflow, measuring temperature differences across the coil, confirming that all modes operate correctly, and verifying controls. At Teton Heating & Cooling, we do not treat these as optional add-ons. They are part of delivering a system that matches what you were promised. Our commitment to avoiding shortcuts and our thorough inspection process extend through installation day and into final testing. That approach, backed by our work warranties, helps protect your investment and reduces the chance that hidden setup mistakes will cut your system’s life short.
Get an AC Installation in Teton County That Works With Your Home
Most long term AC problems in Teton County are not random bad luck. They usually come back to a handful of decisions about sizing, ductwork, placement, and setup that were made on installation day. When those decisions do not account for our altitude, climate swings, and typical home layouts, the result is higher bills, more repairs, and rooms that never feel quite right. The good news is that with the right approach, these mistakes are avoidable.
Designing and installing an AC system that fits your Teton County home takes time, careful inspection, and local experience. That is how we approach every project at Teton Heating & Cooling. If you are planning a new installation or replacement, or if you suspect your existing system was not installed correctly, we can walk your home with you, answer your questions, and recommend a solution that is built around your space. To talk with our team or schedule a visit, call us anytime.