Heating, Ventilation and Air Conditioning

Heating, Ventilation and Air Conditioning plant (HVAC) typically consumes about one third of all energy used in larger commercial buildings. Some small buildings have heating only therefore correspondingly use less energy.

The same principles apply for small premises with heating only as to larger sites with central plant consisting of chillers, boilers, circulated chilled and heating water, cooling towers, pumps and air handlers.

The basic energy saving principles include:

• Don’t cool or heat areas that are not necessary.
• Only provide cooling or heating for as long a time as is required.
• Do not heat and cool the same space at the same time.
• Keep the plant well maintained.

The following are some specific areas that should be regularly checked for a larger air conditioning plant:

• Check that fans, pumps, chillers, boilers etc are turned off at night if they are not required.
• Check that timeclocks controlling plant are set to the correct time, control correctly and are programmed for the correct time schedule.
• Check the temperature set points in each area to ensure that they are reasonable common areas are not fighting one another. e.g. one zone trying to heat with the adjacent zone trying to cool.
• Set the temperature setpoints seasonally. In summer the areas may only need to be cooled to 22- 23oC and in winter may only need to be heated to 20oC.
• Ensure that there are no heating or cooling loads in close proximity to the room sensors.
• If the plant is controlled by a Building Management System (BMS) ensure that it is checked by qualified controls engineers at least annually to ensure plant operation is optimised.
• Check if variable speed drives (VSD’s) on fans and pumps are controlling correctly.
• Ensure all HVAC main plant is maintained regularly. Energy consumption will increase significantly if the mechanical plant is not maintained.
• Ensure that heating and chilled water pipework is fully insulated.

More Energy Saving Tips are available in the Air Conditioning section of the Energy Saving Tips page by clicking here: link to Air Conditioning section

Maintenance

The following are some recommended minimum maintenance practices for HVAC plant:
Monthly.
• Check air intake screens and clean as required.
• Inspect air dampers and ensure they can fully open and close and operate automatically.
• Check V-belts for frays, cracks, and nicks, tension and replace as necessary.
• Check fans are running freely.
• Check for abnormal noises and vibration.
Quarterly.
• Check air filters and clean or change as needed.
• Check motors, bearings, and blower fans and lubricate as required.
• Check heating and cooling coils every 3 months, and clean as needed.
• Have chiller and refrigeration plant serviced by a qualified engineer.
• Have boiler plant serviced by a qualified engineer.
Annually.
• Ensure all control systems are operating effectively.
• Test water treatment levels for closed heating and cooling water circuits.