What Is an Economizer?

Economizers use cool outside air to chill the indoor area of a constructing. The system consists of dampers and actuators that draw cool outside air into the constructing’s HVAC system.

When the outside air temperature is decrease than the temperature setpoint indoors, the economizer dampers open to herald extra outside air. This cool air passes via the HVAC system and circulates all through the constructing, lowering the necessity for mechanical cooling. The economizer controller displays temperature and humidity sensors each indoors and outdoor.

The controller modulates the damper place to take care of indoor thermal consolation primarily based on the differential between indoor and outside circumstances. The economizer can present 100% of wanted cooling on delicate days. On hotter days, it offers partial cooling, and the HVAC system’s mechanical cooling handles the remainder of the load. This twin operation considerably reduces vitality consumption in comparison with relying solely on mechanical cooling.

Economizer Parts

An economizer consists of a number of key parts:

  • — The controller processes sensor information and sends alerts to the actuators to modulate the damper place. It consists of management logic to optimize operations.
  • Dampers — Motorized dampers mounted within the exterior air consumption enable outside air into the system. Dampers management airflow path and quantity inside a duct system to take care of a balanced HVAC system.
  • Filters — Consumption filters clear the surface air of particulates earlier than circulating it indoors.
  • Reduction dampers — Reduction dampers exhaust indoor air to stability the inflow of outside air.
  • Sensors — Temperature and humidity sensors monitor circumstances indoors and outdoor.

Correct calibration and upkeep of dampers, actuators, and management sensors are crucial to economizer efficiency and vitality financial savings.

Economizer Sorts

There are two primary forms of economizers utilized in HVAC programs:

Air-side economizers herald cool outside air to chill the constructing immediately. This air passes via the HVAC system quite than recirculating indoor air. Air-side models are the most typical sort.

Water-side economizers cool a constructing’s chilled water loop by circulating it via a cooling tower or fluid cooler. The outside air cools the water, which then circulates all through the constructing to soak up warmth via cooling coils. Water-side models take up extra space however can use “free cooling” at decrease outside temperatures in comparison with air-side sorts.


HVAC economizers are well-suited to massive industrial buildings with sizable cooling calls for. Relying on local weather and different components, they’ll cut back annual cooling vitality utilization considerably. The most typical economizer functions are workplace buildings, colleges, retail shops, information facilities, healthcare services, and industrial buildings.

Any HVAC system that should situation massive volumes of air is an efficient candidate for an economizer. Economizers generally serve single-zone and multi-zone programs as much as 10,000 tons in capability.

In sizzling and humid climates, outside air usually lacks enough cooling capability for economizers. Nevertheless, information facilities positioned in sizzling climates can nonetheless profit resulting from their excessive inside warmth masses.

Vitality Financial savings

By harnessing cool outside air, economizers can cut back HVAC vitality consumption by 30% to 60% yearly. The precise financial savings rely upon a number of components:

  • Constructing dimension — Giant industrial buildings have larger inside warmth masses, rising the necessity for cooling. 
  • Local weather — Temperate and dry areas with huge temperature swings enable for wider use of economizers — functions are restricted in sizzling, humid areas.
  • HVAC system dimension — Bigger air handlers usually serve extra in depth services with larger cooling masses. Economizer financial savings scale up accordingly.
  • Setpoints — Wider differentials between indoor and outside circumstances enable larger use of “free cooling” and better financial savings.
  • Utilization — Services with excessive occupancy and prolonged working hours have larger vitality calls for. Economizers cut back consumption extra in these buildings.

Along with vitality financial savings, economizers deliver air flow and indoor air high quality advantages. Contemporary outside air dilutes indoor pollution and replenishes oxygen.


To maintain vitality effectivity and correct operation, economizers require periodic preventative upkeep. Key duties embrace inspecting dampers and linkages for correct motion and sealing and changing broken gaskets, bushings, and bearings. Actuator motion and response to manage alerts needs to be examined, and malfunctioning actuators have to be changed. The technician ought to clear outside air consumption screens and exchange consumption filters as wanted. 

Sensor accuracy needs to be verified by evaluating readings to a calibrated reference, and inaccurate sensors needs to be changed. Management sequences have to be checked by simulating parameter modifications, and controllers could require adjustment. 

Unfastened {hardware} must be tightened, aid dampers have to be confirmed open as outside air dampers modulate open, and linkages require periodic adjustment. Correct economizer upkeep retains the system working effectively, stopping pricey repairs. 

Economizers needs to be checked by a certified technician no less than yearly. Neglecting upkeep checks can result in economizer issues corresponding to caught dampers, inaccurate sensor readings, and unbalanced airflow, which cut back vitality effectivity.

So, Are Economizers in HVAC Methods Value It?

Putting in an economizer is effectively definitely worth the funding for many massive industrial services. The vitality financial savings shortly pay again the gear value and proceed offering advantages yr after yr. Correctly utilized economizers additionally enhance air high quality by rising air flow to boost constructing occupants’ well being, consolation, and productiveness.

Economizers do require common upkeep and educated operation to understand their full potential. Their efficiency and management settings have to be monitored for optimum effectivity. For small residential and lightweight industrial programs, the price of an economizer is extra difficult to justify. The vitality financial savings could not offset the preliminary expense in an affordable timeframe.

In abstract, economizers present wonderful effectivity good points for giant HVAC gear serving sizable services like workplace towers, hospitals, colleges, and municipal buildings. Their worth comes from important cooling vitality financial savings that proceed all through the constructing’s lifetime.

FAQs About Economizers

Can I set up an economizer on my house’s HVAC system?

Most residential HVAC gear doesn’t help including an economizer. Residential models lack the bodily area and management integration wanted. The vitality financial savings additionally hardly ever offset the retrofit value.

How usually does an economizer want upkeep?

Economizers needs to be inspected no less than quarterly. Sensor calibration and practical testing needs to be carried out yearly. Crucial parts like dampers may have repairs or substitute each 5 to seven years.

What are the disadvantages of utilizing an economizer?

Potential economizer drawbacks embrace a better outside air consumption dragging in mud and pollen, potential added noise from consumption followers and dampers, and the necessity for normal upkeep. Nevertheless, these points are often minor in comparison with the vitality financial savings.

Can an outdated HVAC system be retrofitted with an economizer?

It’s usually potential to retrofit an current air handler or rooftop unit with an economizer. An evaluation of wanted structural and ductwork modifications is required.

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