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Commercial Air Conditioning, Commercial HVAC

Looking to Reduce Energy Costs? Get an HVAC Economizer

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Last Updated on March 15, 2018


hvac economizer

What exactly is an HVAC economizer? Any derivative of the word “economy” is appealing to us consumers because it indicates that we stand to save something whether it is from an operational or financial standpoint. So as you probably guessed, an HVAC economizer will save your business money on utility bills. Let’s take a look at how an HVAC economizer is a savings tool well-worth your initial investment.

An HVAC economizer will promote HVAC energy efficiency

If someone told you there were HVAC energy solutions that could save you a bundle by significantly reducing HVAC energy consumption, your interest would be piqued, right? Well, an HVAC economizer does precisely that. The HVAC economizer energy savings potential makes it an essential add-on for high-end homeowners, business owners and property managers to consider.

An HVAC economizer saves you money by pulling cooler outdoor air into your space. This type of cooling is known as “free cooling” because it does not rely on your HVAC’s equipment to cool the air. Places that are hot and humid year-round are rarely good candidates for an HVAC economizer because the outdoor climate is seldom cool and dry enough to benefit your indoor space.

According to the New York Division of Code Enforcement and Administration, when properly installed and maintained, an HVAC economizer reduces mechanical cooling up to 75-percent.

Where can you install an HVAC economizer?

An HVAC economizer sometimes comes built-into rooftop HVAC equipment. If your system does not have an HVAC economizer, air conditioning professionals can perform a retrofit to add one. Adding an HVAC economizer does not require substantial structural or mechanical work. The devices are moderately sized, so they do not need much more space than your existing unit encompasses.

Although a cooler, dryer climate is the best fit for an HVAC economizer, these devices are an effective energy savings tool in climates where it is hot during the day, but cool at night or only experience short seasonal bouts of hot and sticky weather.

Many states have building codes that require the installation of an HVAC economizer for energy conservation purposes. Though Florida, which is hot and muggy most of the year, does not require the installation of an HVAC economizer, New York requires the inclusion of an HVAC economizer in new construction outfitted with HVAC systems that have a cooling capacity of more than 65,000 BTU’s per hour. This requirement does not apply to residential space, hotels, and supermarkets.

HVAC energy solutions: How does an HVAC economizer work?

The HVAC economizer draws in outdoor air, providing the air is below the set temperature and the humidity is lower than a set percentage. This reduces the time your AC is running, which reduces your HVAC energy consumption. Dampers control the amount of air pulled in, recirculated and exhausted from your building.

Logic controllers and outdoor temperature sensors decide if weather conditions are proper for the economizer to operate. Actuators, which are motorized controls, open and shut the dampers when receiving direction from the logic controllers. When the outside air meets temperature and humidity requirement, the exterior damper opens and the air conditioning compressors turn off.

If the outdoor temperature is too hot to supply cooling, the damper closes causing reduced ventilation. The return will open and the exhaust fan will close. The compressors will restart the mechanical cooling process.

Different types of HVAC economizers that promote HVAC energy efficiency

Dry bulb economizer
The dry bulb economizer senses only the temperature of the air and not the humidity. Dry bulb economizers are less costly to install and maintain, but may not provide optimal comfort because these devices do not take humidity levels into consideration.

Single enthalpy economizer (wet bulb)
The single enthalpy (measurement of energy content in the air that includes heat and humidity) uses a sensor to measure outdoor heat and humidity to determine the operation of the economizer.

Differential enthalpy economizer
A differential enthalpy economizer uses two sensors. One measures outdoor enthalpy and the other measures return air enthalpy.

Your HVAC economizer and preventative maintenance

If you want to maximize your HVAC economizer energy savings, routine maintenance is critical. Sitting on a rooftop and not visible, many things can go wrong and you might not necessarily know it until you scrutinize your energy bills. Dampers might close or not seal properly. Sensors can lose accuracy and need recalibration.

There are a lot of moving parts and seals subject to wear and tear. The result will be a waste of energy and money. HVAC experts recommend an inspection of an HVAC economizer before and after each cooling season.

Quality equipment and proper installation of your HVAC economizer

Because the rooftop is the likely location of your HVAC economizer, you want to make sure your vendor installs quality equipment and parts that can withstand the outdoor elements. Durable materials are essential considering the economizer’s many moving parts.

One of the most critical decisions you will make is choosing the right installer. If you consider that an economizer can reduce mechanical cooling up to 75-percent and HVAC system can account for as much as 50-percent of your energy costs, you cannot afford to hire just anyone for the job. A recognized HVAC company like Arista Air employs highly trained and experienced technicians to ensure the proper installation of your HVAC economizer.

For other energy savings tips, check out this related article: How to Save Energy in Commercial Buildings

Warning: Your HVAC or commercial refrigeration refrigerant might be illegal in 2 years

It is important to keep in mind the 2020 phase-out of R-22 when weighing expensive HVAC replacements.

Do you have older HVAC or commercial refrigeration equipment? Due to EPA regulatory changes, R-22 refrigerant (the standard used to power AC and commercial refrigeration systems for decades) becomes illegal in less than 3 years. Get informed about how this change impacts you with this information bulletin. R-22 Refrigerant Phase Out: Do You Need to Replace Your AC?.

R-22 refrigerant phase out