Building managers and owners are continually seeking new ways to save money on utility bills. This is especially true when it comes to HVAC systems which are in operation year round. Luckily we have technology, such as economizers, to help cut cooling costs. 

Economizers essentially use free cool air to help cool your buildings. However, like anything else they require maintenance and care, and in the case of RTUs with economizers it quite literally pays to be knowledgeable about your equipment.

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Economizers allow for “free cooling”; when appropriate, 100% outside air is brought in to cool the building without any air conditioning.

 

They sense outside temperature and humidity levels and if these numbers are within a given range, the cooling system will then use free, cool air from outside and save costs by avoiding the running of the compressor.

 

Economizers in good working condition can also extend the life of your compressors as they won’t be in use as much.

Technicians should be examining economizer operation annually to ensure owners are saving the most in operational costs.

It therefore pays to know more about economizers and what system you are using. There are four types of economizers commonly in use today. First is the dry bulb economizer which uses a sensor to detect outside temperature and open a vent which mixes cool outside air in the HVAC return. These economizers do not detect humidity levels however, which could impact the comfort level of occupants.

The single enthalpy economizer does detect humidity, however these can also have issues, as the sensors and controls have been known to break down over time. The differential enthalpy economizer actually senses both the outdoor air and the buildings return air to open and close dampers for optimal cooling.

Finally, the most complex economizer is the integrated differential enthalpy economizer, which is able to communicate directly with your indoor thermostat for real time adjustments. All of these economizers can either be built into HVAC units or retrofitted.

The single enthalpy economizer does detect humidity, however these can also have issues, as the sensors and controls have been known to break down over time. The differential enthalpy economizer actually senses both the outdoor air and the buildings return air to open and close dampers for optimal cooling.

Finally, the most complex economizer is the integrated differential enthalpy economizer, which is able to communicate directly with your indoor thermostat for real time adjustments. All of these economizers can either be built into HVAC units or retrofitted.

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Economizers can also use what is known as demand-control ventilation. Sensors will detect carbon monoxide levels, which will naturally rise as more people occupy a building, and if levels are too high they will open and allow more fresh air to mix with the space.The tricky part about economizers is that if they break or are not operating properly the owner may never know what is actually going on as the actual HVAC system will continue to work just fine.

This is why it is so important to regularly have the economizer checked. Controls, sensors, and actuators can fail over time and owners may never know, unless they notice utility bills rising.

When it comes to saving money, building managers and owners shouldn’t forget about equipment maintenance, especially economizers, which are actually designed to save money. Also, if you’re in new construction, be sure that your RTUs include economizers.

For more information or have your equipment checked, contact our Services team today.