Don’t Lose Your Cool – Let Seattle Air Conditioning Size the Central Air Conditioning Unit for Your Office!

Are you considering installing or upgrading an existing central air conditioning system in your office? Spring is the time to assure that your employees will be comfortable in the impending hot, humid days of summer! Seattle Air Conditioning can assess your needs and determine the most efficient unit to install for your specific application.

When sizing a whole-structure (central) air conditioning system, there are several factors to be taken into account:

  • Climate
  • Age and condition of structure
  • Total square footage of windows in structure
  • R-factor of structure’s insulation
  • Direction structure faces
  • Shade factor of structure

Each of the listed factors are equally important when sizing a central air conditioning system for your business.

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Using the listed factors with a specific formula, Seattle Air Conditioning‘s North American Technician Excellence (NATE) certified personnel will determine the most efficient, effective size and type system for your business’ cooling needs. Especially in such humid climate as Seattle, it is crucial that your unit be sized properly! Your employees will perform to their potential within a properly conditioned atmosphere. There are additional financial considerations to installing the correct air conditioning system.



Air conditioners are rated by the quantity of British Thermal Units (BTU’s) of heat a system removes from a space per hour. A BTU is the amount of energy required to raise the temperature of 1 pound of water 1 degree Fahrenheit in 1 hour. The rating of an air conditioner in tons refers to:

1 ton =12,000 BTU’s =

amount of energy required to melt 1 ton of ice in 1 day

It is essential that you understand that the rating of an air conditioning unit is by no means an indication of the system’s efficiency. A cooling unit’s efficiency is determined by proper sizing for a specific structure.


If your air conditioning unit is too small, expect:

  • That your office will never cool properly
  • That the system will have difficulty achieving set temperature. As such, the unit will seemingly run continuously; resulting in increased energy consumption and higher electric bills.


An air conditioner that is sized too large will result in equally serious problems:

  • Continuous cycling – short periods on followed by short periods off
  • Inconsistent air temperature throughout your building
  • Inability to remove humidity due to short cycles
  • Excessive wear and tear on the compressor and other parts


With the unit size determined, the design and sizing of ductwork is equally important. Correctly sized ductwork will allow for adequate movement of conditioned air into each area of the structure. The total length as well as the total number of angles must be considered when designing the system. A properly designed, installed and maintained system will keep your office comfortably cooled and dehumidified throughout the summer months.