Energy Conservation in Commercial Buildings

There’s no doubt that energy conservation in commercial buildings (or any building for that matter) is important.  Reducing operating costs are important for valuations, freeing capital up for other projects or simply reducing the carbon footprint of your building, or portfolio of buildings.  There are many different ECMs (energy conservation measures) available to companies to help achieve these goals, and almost always the decision to use certain measures comes down to “I have to be at 3 years or less for the simple payback”.   While financial metrics are important, I believe that this focus often obscures the soft benefits to the building’s occupants and workers.

 A noise study was recently completed where a corporate kitchen’s noise levels were measured before and after the installation of variable speed controls on both the hood exhaust and supply fans. Traditionally kitchen exhaust fans run at 100% speed for constant periods of time.  With the addition of a variable speed system, like Melink Intelli-Hood, fan speeds are reduced to slower speeds when cooking isn’t at its maximum.  From an energy savings perspective there are two buckets of operational cost reductions, fan energy and conditioned air.  The chart below shows that when the kitchen fans are operating at 100% speeds the decibel level is just short of what a fire alarm sounds like when activated.  With the addition of the variable speed controls, the site realized much lower average fan speeds, as well as a reduction in kitchen noise levels to just below conversational speech, or a reduction of 11 decibels. 

The financial metrics for this project met all approval hurdles and the site is very happy.  For a moment, think about the Chef and his staff.  Their work environment has now become much more quiet.  They can hear each other better when they’re coordinating and preparing meals for several hundred employees each day.  Shouting and miscommunication is greatly reduced, and their environment is more pleasant.  This particular improvement would be hard to show on an income statement…or would it? 

As one example, within Seniors Housing, Dining Services is consistently near, or at, the top in employee turnover percentages.  The current industry turnover rate is 36.91%, (McKnight’s Senior Living, Salaries and Benefits Report 2017-2018) with Certified Nurses Aids coming in a close second at 34%.  It will cost a facility approximately $2,500 in recruiting and training to backfill a single new employee.  Compound that amount with multiple hires each year and it gets expensive very quickly.  If along with reducing energy costs a site can also create a better work environment for its full time employees (FTE), then perhaps that large expense can begin to be reduced and more employees will remain on the payroll instead of seeking other places to work. 

See the full case study here or contact us today to learn more about Intelli-Hood and the benefit of kitchen hood controls.

When Should My Building Be Balanced?

A proper air balance within a building is an important factor for providing a healthy and comfortable indoor environment for occupants.  Like many other critical building systems, the air balance must be maintained over time, and isn’t something that you can simply “set and forget”.  So then, when should a building be balanced?  Here are some common events that would trigger the need to perform an air balance.

New Construction:

Every building that has some form of HVAC system (heating, ventilation, and air conditioning) should be balanced when it is first constructed. By this, I mean that the HVAC systems should be inspected, tested, and adjusted to ensure that they are operating correctly, efficiently, and as intended by the design engineer and as expected by the building owner. A balanced building will provide a comfortable and healthy indoor environment for the occupants, delivered in an energy efficient manner, and will have a proper positive pressure. Select a TAB professional to perform the air balance who is objective, meaning that they are hired directly by the building owner and are independent of the installing contractors and equipment manufacturers, who is experienced in your particular type of building and HVAC systems, and who is certified by an industry-recognized accrediting agency, like NEBB or AABC.


The building should be rebalanced during any major remodel event, such as expanding the building or changing the functional use of a space within the building. This is important because the HVAC system was originally designed and balanced for specific use conditions, and when those conditions change, the system will need to be readjusted. Be sure to consult with your mechanical design engineer prior to the remodel to verify that the existing HVAC system can handle the new demands. The building should also be rebalanced anytime elements of the HVAC system are modified or replaced, such as when ductwork is rerouted or when aged equipment is upgraded. This is important for verifying that the new equipment is installed correctly, operates properly, and is adjusted for the design conditions. For a building that has cooking operations, it is important to also rebalance whenever the cooking appliances are relocated or replaced with equipment of different use or heat load, such as replacing an oven with a fryer. This is significant because a kitchen ventilation system is designed for a specific bank of appliances. When the appliances and cooking operations change, the ventilation system will need to be adjusted to ensure it correctly captures and contains the heat and effluent produced.

Periodic Tune-up:

Even if a building has been balanced during the original construction, and it is not undergoing any remodels or equipment replacements, it should still be rebalanced periodically. This is because the performance of the HVAC system can change over time due to normal use and wear and also due to adjustments made by operations and maintenance personnel. Examples of this are when an operator switches the fan mode of the thermostats from ON to AUTO or when a service technician closes the outside air dampers in a rooftop unit in an attempt to fix a comfort complaint. For the complete building HVAC system, I would recommend a proactive rebalance frequency of every two to three years. This will ensure that the systems operate effectively and efficiently throughout their lifecycle and will help prevent the very costly issues created by having a building out of balance for a prolonged period of time.

Want to understand more about air balances? Read about air balance basics for existing facilities, watch our video on how an air balance works, or contact us to learn more!