Energy Saving Tips For Your Commercial Building
When It Comes To HVAC, Size Matters
Choosing the proper size of heating, ventilating and air-conditioning (HVAC) equipment is critical to the performance and efficiency of your system. Although some owner and managers of commercial buildings feel a bigger system will do a better job, this isn’t always the case. For optimum results and energy efficiency, a Certified Energy Plans Examiner such as Kramer Engineering Services should choose the size of your system, based on the needs of the heating or cooling load.
If a unit is too large, its cycle times will be reduced. This prevents the unit from reaching maximum efficiency and, in turn, causes higher operating costs. It can also keep the unit from running long enough to remove excess humidity from the building, resulting in a decrease in comfort and possibility of unhealthy mold or mildew.
If your building has an existing system that needs to be replaced, your new unit may not be the same size and capacity as the old one. Changes in the building, such as additions, renovations and insulation, may require a size different than the original. A new unit will be more efficient than the old one, so even if the building hasn’t changed, a smaller HVAC unit may work.
The way the Certified Energy Plans Examiner will determine the best-size unit is by conducting heating and cooling load calculations, using either the entire building, or by room-by-room calculations. The load is the amount of heating or cooling that the unit must supply in order to maintain a specified temperature. Kramer Engineering Services performs load calculations using the California State approved EnergyPRO program.
These calculations are determined by several factors, including:
- type, size and number of windows
- total square footage of the building
- air filtration
- the loss of heating or cooling in air ducts in unconditioned spaces
- climate moisture
- shading devices, such as awnings.
Other energy-saving tips for commercial and office buildings
- Replace rooftop heating and cooling units with high-efficiency models. They can reduce operating costs by 15 – 30%.
- Ensure that the building’s HVAC units are equipped with commercial-grade, programmable thermostats. When the building is unoccupied, set the thermostat to be 10 degrees warmer for summer, and 10 degrees cooler in winter. This will save about 10% on your electric bill.
- Make sure that the economizers on your air conditioning units are functioning properly. Economizers monitor the temperature of the outside air, and the air in the air return ducts. When the outside air is cooler, dampers open to bring in cooler outside air. Check that the dampers are operating properly, and are unencumbered outside.
- Check exhaust fans and air handlers to make sure that exhaust fans are off, and that outside air is not being brought in when the building is unoccupied.
- Consider installing variable speed drives for fans that have changing loads and are 5 HP or larger.
- Upgrade interior lighting to high-performance T8 fluorescent lighting. These new ballasts and lamps use 10 – 40% less energy to deliver the same amount of light as older systems. They can pay for themselves in as little as a year and a half.
- Use motion and occupancy sensors to control lighting where occupancy is intermittent, such as conference rooms, bathrooms, auditoriums, etc.
- Use daylight when possible, if the daylight does not cause solar accumulation in summer. Natural lighting also improves employee productivity.