Colorado summers are hot, dry and short, which makes air conditioning a genuinely different design problem here than it is in a humid climate — and makes oversizing both easy and costly.
AT A GLANCE
- Typical lifespan
- 12 to 17 years for a residential condenser
- Best time to install
- Spring, before the first heat wave books everyone out
- Refrigerant note
- R-22 systems can no longer be topped up with new refrigerant
- Cold-climate heat pumps
- Now viable at Front Range design temperatures
- Evaporative alternative
- Viable in this dry climate and worth discussing
A dry climate changes the problem
Most air conditioning guidance is written for humid places, where a large part of the system’s job is pulling moisture out of the air. Here, that is barely a factor. What matters instead is a very large daily temperature swing, intense high-altitude solar gain through windows, and cooling seasons that are hot but short.
Practically, that means two things. Oversizing is even easier to do and even less useful, because you are not relying on long run times for dehumidification. And shading, window area and orientation matter disproportionately in the load calculation, because direct sun at altitude puts more energy through a west-facing window than the same window would receive at sea level.
Charging by measurement, not by feel
The single most common installation error we see is an incorrectly charged system. Refrigerant charge is not something you judge by gauge pressure and experience — it is verified by measuring superheat on a fixed-orifice system or subcooling on a TXV system, against the manufacturer’s published targets for the conditions on the day.
A system that is overcharged or undercharged by ten percent will still blow cold air. It will also use more electricity for less cooling and fail earlier than it should. You cannot tell by standing in front of a vent, which is exactly why it gets skipped.
Heat pumps, which are an air conditioning decision
A heat pump is an air conditioner that can also run backwards, so this is where it belongs rather than under heating. Cold-climate models have genuinely changed in the last several years and are now worth considering on the Front Range, where they were not a serious option before — they hold useful capacity well below freezing.
The economics depend on your electricity rate against gas, and the comparison is specific to your house rather than general. We will run it that way. If gas service already exists and rates are favourable, a high-efficiency gas system may still win, and that is a fine outcome to arrive at.
The capacitor conversation
If there is one piece of preventative maintenance worth doing on an air conditioner it is testing the run capacitor annually. It is an inexpensive component with a predictable service life that degrades gradually. A weak capacitor makes the compressor work harder to start, every single cycle, until the compressor fails — and a compressor is most of the value of the outdoor unit. Testing it takes two minutes.
COMMON QUESTIONS
Why is bigger not better for an air conditioner?
Because an oversized system cools the air to temperature before it has run long enough to do anything else. In humid climates that means it never dehumidifies. Even in a dry climate like ours it means short cycling, uneven room-to-room temperatures, more wear on the compressor, and worse efficiency than a correctly sized unit running longer cycles. Sizing is a calculation, not a rounding-up exercise.
My AC is blowing warm air. What is wrong?
The most common causes are a dirty filter or coil restricting airflow, a tripped breaker on the outdoor unit, a failed capacitor, or low refrigerant from a leak. Low refrigerant is worth understanding: an air conditioner does not consume refrigerant. If it is low, there is a leak, and simply topping it up is paying to release refrigerant into the atmosphere and be back next summer.
My system uses R-22. What are my options?
R-22 has been phased out of production, so it can no longer be topped up with newly manufactured refrigerant and reclaimed supply is expensive and shrinking. If an R-22 system has a leak, repairing it is usually not economic. That does not mean you have to replace it the moment you hear the word, but it does mean you should plan for replacement rather than be surprised by it.
Do heat pumps actually work in Colorado winters?
Cold-climate heat pumps do, in a way that was not true a decade ago. Modern variable-capacity units hold useful output well below freezing and are commonly paired with a backup heat source for the coldest stretches. Because a heat pump both cools and heats, it is really an air conditioning decision rather than a heating one. Whether it makes sense at your house depends on your electricity rate, your insulation, and whether you already have gas service — if you do and rates are favourable, a high-efficiency gas system may still be the better answer, and we would rather tell you that than sell you the more expensive install.
Would evaporative cooling work at my house?
Possibly, and it is a fair question in a climate this dry, where evaporative cooling is genuinely effective and uses far less electricity. The trade-offs are that it adds humidity, needs a constant supply of outside air so windows have to be cracked, and struggles during monsoon season humidity. We will give you a straight comparison for your house rather than steering you to whichever we would rather install.
How often does an AC need servicing?
Annually, before cooling season. The service that matters is cleaning the condenser coil, checking the charge properly against superheat and subcooling, verifying airflow, and testing the capacitor — which is a cheap part that fails predictably and takes the compressor with it if it is ignored.