August 6, 2015
Overlooked Energy Efficiency Fixes for HVAC Systems
You’ve heard the usual energy-saving advice: Use light sensors, turn off equipment when not in use, use Energy Star products, etc. but there are three low-cost, energy-saving strategies that should be performed on your HVAC systems that are often overlooked.
- Economizer Dampers – When performing energy audits, Continuum Services often finds the dampers that manage the proper flow of outside and return air through the building are set incorrectly. When the system is installed, if the outside air (OA) dampers are set to “minimum position” as specified by an engineer, they are set to a certain opening position. In extremely cold or hot weather, bringing in more than the required amount of OA increases the load on the heating or cooling system, increasing the cost. It’s recommended facility managers continually check these systems for proper operation.
- Variable Frequency Drives (VFD) – VFDs, part of an overall building automation strategy, save energy by reducing the speed of the fan or pump they serve. The energy used by a rotating piece of machinery, such as a fan or pump, varies directly as the cube of the speed ratio, down to about 30%, depending on the application. Problems occur when VFDs, which are designed to run at varying speeds depending on the system’s requirements, are set to manual, or bypass, and then left there. When Continuum Services performs energy audits, our technicians often find one or more VFDs set to “bypass.” This means they’re operating at a steady 60 Hz, rather than varying the speed according to the needs of the equipment they’re controlling.
- Coils – Proper cleaning of your building’s heating and cooling system coils goes a long way toward improving energy
efficiency, comfort and IAQ. However, many people don’t bother cleaning the coils of their system, either because they don’t understand the potential benefit or they don’t know how to do it effectively. Today, most coil cleaning involves spraying water and a cleaning solution that will reach only into the first few rows of coils. Coil cleaning with a specialized steam solution gets deep into the coils, cleaning out the particulate and the dirty and hazardous biofilm. When done by a properly trained technician using proper equipment, cleaning this way also prevents the fins from being bent out of shape, preserving their efficacy. With proper cleaning, we have seen HVAC system efficiency improve from 10% to more than 1,000%!
Remember you should still look at lighting, water use, plug loads, windows and the building envelope, in addition to the HVAC equipment itself for energy saving procedures. To find out more contact Continuum Services at 248.286.5200 or info@continuumservices.com.
Source: Newman Consulting Group, http://www.newmanconsultinggroup.us/green-building-blog/top_three_overlooked_energy_efficiency_fixes_for_hvac_systems
