Economizer Calculator

Estimate HVAC economizer savings from free cooling based on climate and system parameters.

Annual Energy Savings
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kWh/year
Annual Cost Savings
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Free Cooling Hours
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hours/year
% of Cooling Hours
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Avg Load Offset
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tons (avg during econ mode)
CO2 Reduction
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lbs CO2/year
Simple Payback
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years (est. $3-5K install)

How HVAC Economizers Save Energy

An air-side economizer uses cool outdoor air for free cooling when conditions are favorable, reducing or eliminating the need for mechanical cooling.

  • Dry bulb economizer: Opens when outdoor air is below the high limit setpoint
  • Enthalpy economizer: Compares enthalpy of outdoor and return air for better humidity control
  • Savings vary significantly by climate zone; marine and cool climates see the most benefit
  • Code requires economizers for most commercial systems above 54,000 BTU/hr (ASHRAE 90.1)

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