Yes. We size evaporative coolers by calculation, not by rule of thumb — matching CFM output to your home’s volume, layout, and air-change requirements, then verifying your ductwork and relief-air path can actually handle it.

How Evaporative Sizing Works

Swamp coolers are rated in CFM — cubic feet per minute of air moved — rather than tons of cooling capacity. The calculation starts with your home’s cubic volume (square footage times ceiling height) and the number of air changes per hour needed for effective cooling in our climate. Homes with high or vaulted ceilings, open floor plans, or heavy west-facing glass need more than the raw square footage suggests.

What Else Factors In

  • Ceiling height and total volume, not just floor area
  • Floor plan — open versus compartmentalized
  • Window area, orientation, and afternoon sun exposure
  • Attic and wall insulation levels
  • Existing duct size, layout, and condition
  • The relief-air path — where the air exits the house

Both Errors Are Real

An undersized cooler runs constantly and still loses ground on a 100-degree afternoon, which is the complaint we hear most. An oversized one is not harmless either: it can over-pressurize the house, create uncomfortable drafts, waste water, and push more moisture indoors than you want. Correct sizing is a target, not a floor.

Ductwork Is Half the Answer

Evaporative systems move much larger volumes of air at much lower pressure than refrigerated systems. A correctly sized cooler on undersized or leaky ducts will still deliver weak airflow at the registers. We evaluate duct capacity as part of sizing rather than treating it as a separate problem — which is also why refrigerated air conversions so often require duct work.

Do Not Forget the Exhaust Path

Unlike a closed refrigerated system, a swamp cooler needs somewhere for air to go — cracked windows or a dedicated relief vent. A house sealed up tight will not cool no matter how well-sized the unit is. It is one of the most common causes of “my new cooler does not work.”

Our technicians have sized evaporative coolers for Albuquerque homes since 1971. Contact B. Carlson for an assessment in Albuquerque or Rio Rancho.