Air conditioners: under-performance and installation

Many air conditioners aren’t installed properly, lowering their performance levels and making high-efficient units performance equivalent to that of old inefficient models.

Leaky ducts, over-sizing and inadequate refrigerant charge are three common causes of AC under-performance, often associated with installation. But there are others. When installing a new air conditioning, pay attention to the basic rules we list below.

Sizing

AC over-sizing is common, and a source of low-efficiency. Over-sizing causes air conditioners to run in short cycles, wasting energy (since the unit runs some few minutes of every cycle just to cool down the coils, ducts and fins).

See: Air Conditioners Sizing

AC duct sizing, insulation and location (Central air conditioners)

Avoid installing the AC ducts in the attic and unconditioned spaces. They should be preferably located within the conditioned space to minimize the effects of leaky ducts. Any possible attic ducts should be heavily insulated (all ducts should be properly sealed with duct mastic).

Air leakage (Room air conditioners)

Use foam insulating material to seal openings and gaps related to room air conditioners. Fit the unit snugly into its wall or window opening to minimize leaks.

Registers (Central and split air conditioners)

The number and capacity of return and supply air registers is very important. Just make sure that supply registers deliver enough cool air and return air registers carry enough warm air back.

Units Location

Choose the shadiest side of your home to install room AC units or central AC condensing units. Locate room air conditioners in wall areas or windows as near the center of the room as possible. AC thermostats should be located away from windows, supply registers or any other heat sources.

Refrigerant charge and airflow rate

Without the exact refrigerant charge and air-flow rate the AC will function improperly.

See:

Maintenance
Professional Technician Services
AC filters
Refrigerant charge
Outdoor Coils Cleaning
Indoor Coils Cleaning
Blower Cleaning
Room air conditioner maintenance