For most building and facility managers, maintaining comfort and reducing energy and capital equipment costs is high on their list of priorities. Achieving this involves identifying and resolving equipment issues that can negatively impact building efficiency, thus reducing comfort, increasing operating costs and capital expenditure.
Today, the pursuit of an energy-efficient infrastructure, is forcing organizations to explore ways to efficiently reduce energy waste and corporate carbon footprints. As such, they can no longer afford to dismiss the untapped energy and facilities savings that exist across their building portfolios.
Since HVAC systems take up a large part of a building’s energy consumption, it stands to reason that facility managers should look for ways to make sure that their HVAC systems are running as efficiently as possible, in order to reduce energy use.
To reduce energy spend, facility managers need to understand load shifting and thermal mass cooling and how they can leverage these concepts to maximize building efficiency.
Adaptive Energy Management - How to Use Your Buildings as a Battery
Raising the setpoints by an extreme amount, > 4 - 5 degrees, when the building is unoccupied isn’t a good idea because, not only does your HVAC system continue to work even harder during peak periods to reach the occupied setpoint, the building also stores up additional heat throughout the night.
Load shifting isn’t about increasing the intrinsic efficiency of the RTU (rooftop air conditioning unit). It, however, reduces the heat load on the building and shifts dealing with the majority of the remaining heat load to a more efficient time, when it’s cooler outside.
You should start the system up early and/or run it periodically overnight (when energy costs are low) to reduce the heat stored in a building’s thermal mass, making it easier to achieve the setpoint when the building is occupied during the day.
Essentially, the core objective of thermal mass cooling is to use the building itself to reject heat energy. The building is used as a “battery” of sorts to store cold energy during the night (when loads on the HVAC system is low because of the cooler night air and energy is cheap).
The process of thermal mass cooling is a core concept in Adaptive Energy Management. AEM focuses on cooling the building infrastructure and contents down so they can be used to store “cold” energy, enabling it to overcome radiant sun energy during the day.
For part 2 of this post series, click here.
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