Building Energy Resilience

Throughout the commissioning process, we often find issues with accessibility to equipment, whether it be a heat pump above a ceiling grid or an air handler in a mechanical room. Accessibility to all aspects of a unit is frequently overlooked during the design and construction process. Having adequate clearance is important for the building owner and the maintenance faculty.

I recently had the opportunity to familiarize myself with the Energy Star Portfolio Manager system, which is a free online tool to track and analyze a building’s energy usage via benchmarking. Benchmarking has been previously blogged about by Ben Fowler and Jennifer Chiodo. Certain property types (e.g., hospital, medical office building, office building, etc.) are eligible for an Energy Star score when you have at least 12 months of utility data.

Energy metering devices (also known as data logging meters) are improving rapidly. Data logging meters, such as power and light intensity loggers, are important tools for diagnosing building system issues and/or calculating how much energy certain equipment is using. They also allow you to see how individual equipment is performing over time, which is key for measurement and verification (M&V).

Hotels can potentially use very large amounts of energy because of the 24/7 occupied schedule for common areas and the necessity to have local controls in each guestroom. Typically, these controls are not monitored and not adjustable unless manually changed at the room thermostat.

In Part 1 of this blog post series, I discussed the process and reasoning behind why it is important to do functional performance testing (FPT) on your building HVAC system. I also provided examples of issues that can arise during this testing, which are typically easily fixed via the DDC (direct digital control) system programming but would have slipped under the radar otherwise. Another reason this testing is performed is to find opportunities for energy savings. Part of our role as energy specialists is to understand how to tailor HVAC systems to provide the same performance while lowering the energy involved to make it work, ultimately allowing your system equipment and components to have a longer life span.

Functional Performance Testing (FPT) is the process of putting the Direct Digital Control (DDC) system through its paces by manipulating every possible condition the HVAC controls and equipment will ever experience. FPT is an important part of the building commissioning process. Only by testing how the DDC system controls respond to switching from cooling to heating or economizer mode, occupied to unoccupied mode, satisfied to unsatisfied temperatures, or normal power to emergency power, can the building owner know the system will function properly when the contractors leave and the building is handed over. The tests force you to work through the controls sequence language created by the design engineer in a sequential order. As I gain experience as a commissioning engineer, FPT allows me to better understand the “brains” behind why equipment performs and reacts as it does. To make sure a piece of equipment works as intended and can provide the expected performance is the main reason to functionally test HVAC systems.