The importance of Economizers for HVACs – and how NexRev can help your business
In case you’re unfamiliar with them, let’s start by answering the obvious question: What are economizers? In Heating, Ventilation, and Air Conditioning systems, economizers are devices or features that enable a building’s HVAC system to use outside air to cool or ventilate indoor spaces. This is as opposed to using a mechanical cooling system like air conditioning for the same purpose. The obvious advantage of economizers is that they improve energy efficiency by reducing the need for mechanical cooling, particularly during milder or cooler weather.
Type of economizer
There are two common methods of controlling economizers most frequently used in HVAC. The first of these is the Dry Bulb Economizer Method. This method works by introducing outside air to a building when the external temperature is lower than indoors, utilizing the cooler air to lower the temperature of the indoor space directly. This removes the need for mechanical cooling. The Dry Bulb method is best suited for deployment in dry, moderate climates where high outdoor humidity levels are rare.
The second common method of economizer control is the Enthalpy Economizer Method. This method considers both the temperature and humidity levels of outdoor air, determining whether it can provide sufficient indoor cooling by comparing the total heat content (enthalpy) of the outdoor to that of the indoor air. The Enthalpy method is best suited to climates that tend to experience high outdoor humidity levels on a somewhat regular basis.
In both cases, economizers help increase energy efficiency and reduce HVAC operating costs by using the cooling capacity of outdoor air when it’s appropriate to do so. The overall efficiency (and thus performance) of HVAC systems is improved and their contribution to sustainability increased by minimizing their reliance on mechanical cooling.
How do economizers work?
Now that we’ve established what economizers are, let’s look at how they work. It’s straightforward. As we now know, economizers introduce outdoor air to cool the building when the outdoor air is suitable to do so. This is done by opening outside air dampers in the facility to enable the cooler air to be introduced, while shutting return air dampers. Economizers control both the outside air damper and return air damper together in an inverse relationship in order to maintain the correct building pressure while economizing.
Economizer operation can be controlled by the Energy Management System / Building Management System (EMS / BMS), which monitors various parameters, including indoor and outdoor temperatures, humidity levels, and often air quality. Upon a command from the EMS / BMS, the HVAC systems will then adjust the position of dampers to regulate outdoor airflow into the building as required.
Remember that proper maintenance and calibration of economizer systems will be required to make sure that they perform optimally and achieve maximal energy savings on a continuous basis.
Why are economizers important?
With insight into what economizers are and a brief overview of how they work, if it’s not already clear let’s further consider why they’re important. There are several reasons related to the benefits they deliver, mainly energy efficiency, cost savings, and environmental impact. Foremost among these:
- We’ve already established that economizers reduce the reliance on mechanical cooling systems like air conditioning. This means that they’re energy-efficient, significantly lowering energy consumption particularly during milder or cooler weather. Using “free cooling” (outdoor air) can considerably enhance the overall efficiency of an HVAC system.
- Predictably, if reliance on mechanical cooling is reduced, then energy bills for both building owners and occupants go down! That means cost savings are accrued because the HVAC system can use natural resources more efficiently. In regions with a moderate climate, economizers can be used for large portions of the year, so that cost savings can be substantial.
- Increased energy efficiency and lower costs combine to deliver a third benefit; reduced environmental impact, as the former directly contributes to a lower carbon footprint. Using outdoor air for cooling means the HVAC produces fewer greenhouse gas emissions, promoting sustainability and environmental responsibility in the process.
Building owners are incentivized to reduce environmental impact to attract tenants.
- Increasingly, we’re seeing building codes and standards requiring the inclusion of economizers in HVAC systems to enable meeting energy efficiency regulations. Thus, compliance is becoming another of their benefits. More and more buildings are now constructed and operated with a focus on energy conservation, so in this manner, economizers become necessary components in obtaining building certifications and permits.
- Introducing fresh outdoor air through economizers will enhance indoor air quality because outdoor air naturally dilutes indoor pollutants and provides better ventilation. This contributes to better occupant health and well-being because the build-up of contaminants in enclosed spaces is reduced.
To summarize, economizers are an increasingly important component part of HVAC systems. Integrating them into system design today aligns HVACs with the broader goals of energy conservation and sustainable building practices. If you’re not already aware of and working with economizers, it’s likely you soon will be.
How NexRev helps
Efficient operation for economizers is essential. Are the dampers set correctly? Have local settings been changed from the agreed norms for the organization? How do you manage multiple sites across your footprint?
The answer comes from the combination of centralized management and distributed control. With an EMS / BMS – like NexRev Freedom – you can remotely monitor all local conditions from a central console, delivered over a web browser. With distributed monitoring, data from all your HVACs and locations can be consolidated – so you can easily (and automatically) detect when settings are not optimized – and quickly adjust settings.
With Freedom, this can be achieved in minutes, so you can avoid having to manually adjust settings. For many businesses, manual adjustment means that a technician may have to visit a site, adding costs to the business. But Freedom allows you to manage setpoints and other parameters remotely, reducing truck rolls. You can also use automation to make certain that settings are adjusted without human intervention – again, saving time and money.
Economizers are important – but like any other control mechanism they need to be monitored and adjusted occasionally to secure optimum performance. Freedom gives you the power to do this remotely and automatically across all your locations. And, when conditions change dramatically, you can send bulk changes to specific locations and regions – for example, when a cold weather front approaches, or during seasonal storm events.
At NexRev, we’ve been unlocking the power of facility and energy management data with over a million connected devices across North America. Our team of experts is focused on helping you deliver more with your budgets, infrastructure, and assets to create sustainable savings in operations and energy, reducing your risk and increasing operational confidence.
To begin a discussion on how we can help you reduce energy waste, please email us at