Commercial HVAC (heating, ventilating, and air conditioning) systems, essential to the comfort of all indoor work environments, represent 40% of the electricity utilized in commercial buildings across the country. The measures outlined below can result in improved HVAC performance and efficiency, as well as a significant reduction in energy cost.
Steps to Take Before Replacing Your HVAC System
Before making the decision to replace your HVAC system, you may want to consider taking steps to reduce maximize your current (and any future) system’s efficiency.
Some recommendations are provided below:
- Seal HVAC leaks and add insulation to improve efficiency.
- Control ventilation to save energy while maintaining a comfortable work environment.
- Purchase office equipment with minimal heat emission.
- Replace windows with ENERGY STAR qualified windows to improve efficiency.
- Install energy-efficient lights to reduce heat emissions.
- Prevent passive solar gain (i.e., an increase in temperature resulting from solar rays) via cool roofing, window tints, etc. (Conversely, steps can be taken to increase solar gain in cool climates.)
Implementing the above measures will ensure that you receive the maximum efficiency and energy cost benefits from installation of a new HVAC system.
Installing a Commercial HVAC System
While essential to most indoor work environments, commercial HVAC systems (particularly cooling systems, in Texas) result in a considerable portion of commercial energy costs. However, systems are becoming consistently more efficient, with modern air conditioners consuming 30% to 50% less energy than models made in the 1970s. In just a decade, efficiency has improved so significantly that it’s possible to reduce cooling energy costs as much as 20% by installing the newest system.
Steps to take before installing a new commercial HVAC systems:
- Take the steps outlined above to reduce load and maximize efficiency!
- Request an ACCA Manual N (commercial) or a Manual J (home), which will help you to select the right system for your space.
- Do not choose an HVAC system that is too large for your needs. This will increase installation, maintenance, and energy cost. To ensure that your HVAC system is the right size, ask your HVAC dealer to conduct an Air Conditioning Contractors of America’s (ACCA) Manual N Commercial Load Calculation.
- Ask your HVAC dealer to provide quotes (including life-cycle costs) for both standard-efficiency and high-efficiency units. If the high-efficiency unit’s life-cycle cost is less than that of the standard-efficiency, choose the high-efficiency unit.
- Choose only ENERGY STAR qualified Room Air Conditioners and Light Commercial heating and cooling units.
- Install energy recovery ventilation systems that repurpose energy from the exhaust air stream to condition incoming air.
- If applicable (in humid climates), ask your HVAC dealer about supplemental dehumidification to promote comfort and save on energy costs.
- If applicable (in dry climates) consider evaporative coolers to increase efficiency and save on energy costs.
- Install economizers to utilize outside air when the temperature is lower than the indoor air.
- Install ad utilize programmable thermostats.
- Require use of National Electrical Manufacturers Association (NEMA) premium motors for HVAC equipment.
- Evaluate using variable speed drives (VSD) on condenser and evaporator fans.
- If your facility generates significant heat (via cooking, for example), evaluate options for utilizing free-waste heat to save on energy costs.
- Evaluate installation of radiant heating (which warms objects in lieu of air) in warehouses, garages, or outdoor patios.
Commercial System Controls
In addition to reducing load and installing appropriately-sized, efficient HVAC systems, implementing the appropriate controls is essential to maximizing efficiency. Commonly, ENERGY STAR qualified programmable thermostats, system zoning, and CO2 sensors are used to control HVAC systems. While they are ubiquitous on new HVAC systems, they can also be utilized for older systems.
- ENERGY STAR Qualified Programmable Thermostats: Also known as a “setback thermostat,” they allow you to program temperature changes by day and time. According to the U.S. Department of Energy, the proper use of a programmable thermostat can reduce energy costs up to 20 percent.
- System Zoning: Dividing available space into zones, or areas, allows temperature control from each zone and addresses the problem of temperature inconsistencies. When properly used, it also cuts down on energy costs.
- CO2 Sensors: Important to monitoring carbon dioxide and overall indoor air quality, CO2 sensors increase system efficiency and save on energy costs.
Commercial HVAC Maintenance
Frequent maintenance is essential to an efficient and reliable HVAC system. To promote your system’s longevity, the following is recommended:
- Sign up for Precisions Preventative Maintenance Program that includes twice-yearly tune-ups.
- Replace air filters regularly to reduce operational stress.
- Clean the evaporator and condenser coils on your air conditioner, to promote heat transfer.
- Address duct leakage or ensure that you have ample insulation, to prevent loss of cool air and promote system efficiency.
- Repair old valves and steam traps to reduce energy costs.