“If you can’t measure it, you can’t manage it,” said consultant Peter Drucker
referring to improving a business’ productivity. The wisdom in this quote applies to any organization, including facility managers
, as they oversee the operations of their buildings. Those measurements, better described as key performance indicators or KPI’s, are more than just simple targets for commercial HVAC system efficiency or utility costs. KPI’s are established goals that reflect the long-term plans for the building and its systems. Take what is likely the most expensive, complicated, and energy-demanding of all the building systems
: the heating, ventilation, and air conditioning (HVAC). This system and its maintenance demand good metrics to avoid high energy bills, unnecessary repair work, and to serious malfunctions. Facility managers can establish multiple KPI’s for their commercial HVAC system, but two of the most useful are chiller kilowatt per ton (kW/ton) and deferred HVAC maintenance work orders
Chiller Kilowatt Per Ton & An Efficient Commercial HVAC System
The chiller plant
is likely the single largest energy consumer within the HVAC system and if the goal is to keep building energy costs low, KPI’s based on the chiller plant are very effective. The best indicator of chiller plant performance is kW/ton, that is the ratio of the amount of electricity used by the chiller plant per ton of cooling the plant produces. The lower the number, the more efficient the chiller plant is. A good rule of thumb is to keep the chiller plant kW/ton to 0.60 or below. The facility manager has any number of ways to reduce the kW/ton, which is why it is such a good indicator of chiller plant efficiency. To reduce the kW/ton and bring it in line with the established KPI, the facility manager can make changes to condenser and chilled water temperature, supply air temperature, pump speed, and any number of setpoints. When tweaking chiller plant setpoints is not enough to meet the KPI, the facility manager can make a case for more complex upgrades like adding VFD’s to pumps or improving the plant’s control system.
Deferred Work Orders Kept To A Minimum
Studies show that a commercial HVAC system that receives regular preventive maintenance
(PM) operate more efficiently, break down less, and have a longer operating life. Every piece of HVAC equipment in your facility should have a set of PM tasks
associated with it. When your team is busy on other tasks, it’s not uncommon to ignore PM work orders to make more urgent repairs. The skipped PM work orders
are called “deferred work orders” and facility managers should set up a KPI to monitor how much PM work is skipped. Obviously, the ideal KPI for deferred PM work orders is zero. That is, the commercial HVAC equipment received all the PM work scheduled for that period and zero were missed. Although that is ideal, it may not be possible depending on staff size and workload. But even a KPI based on a low number of deferred PM work orders is valuable. If the actual deferred work orders are consistently higher than the KPI, the facility manager needs to address the missed work by increasing his staff, outsourcing the PM tasks to a contractor
, or shift the workload of the team to prioritize PM work. Chiller kW/ton and deferred PM work orders are only two examples of KPI’s to measure commercial HVAC system efficiency and team performance. Facility managers can work with their staff and supervisors to establish KPI’s that track what’s important to meet the goals of the buildings they maintain.