Runtime hours, not years in Columbia
1255 cooling degree days and about 52 days a year above 90F, so running hours are middling and equipment life lands near the national average; the median home dates from 1980, and ductwork and insulation of that era rarely keep up with a modern system, so the ducts are worth looking at before you replace.
1255 cooling degree days and about 52 days a year above 90F, so running hours are middling and equipment life lands near the national average
the median home dates from 1980, and ductwork and insulation of that era rarely keep up with a modern system, so the ducts are worth looking at before you replace
Columbia runs about 1255 cooling degree days a year, which is a direct proxy for how many hours the compressor will actually turn - and compressors wear out by running hours, not by calendar years.
Why this changes what you should buy
In a dry climate the machine is doing almost pure sensible cooling, so the limiting factors move outdoors: how hot the condenser gets, how much dust is packed into its fins, and how many hours a year it runs. Those are maintenance and placement questions more than equipment questions.
Average relative humidity around Columbia sits near 70 percent, which decides whether the machine's job is mostly cooling or mostly pulling water out of the air.
What to ask for, in order
- A Manual J load calculation, not a square-footage rule of thumb
- Shade or at least afternoon relief for the outdoor unit, without blocking airflow
- A maintenance interval that includes washing the condenser coil, which fills fast here
- Duct inspection before sizing, because attic ducts in this climate leak into very hot air
Columbia gets roughly 52 days a year above 32 Celsius, and those are the days a system that is even slightly undersized will never catch up.
Prices in nearby cities
Chattanooga · Clarksville · Jackson · Knoxville · Murfreesboro · Spring Hill · Huntsville · Birmingham · Hoover · Evansville · Tuscaloosa · Roswell