9-11 May 2023
ICC Sydney

There’s a knack to HVAC

A 2015 study by CSIRO revealed HVAC systems represent as much as 50 to 60 percent of a commercial building’s energy use. With such high stakes to your facilities energy bill, there are some practical measures to increase efficiency, reduce operating costs, and improve performance of HVAC systems that can make a big difference in the long-run.

Install an Economiser

An Economiser is a dampered vent designed to save energy and give the cooling system a break; it’s a must have in cooler Australian climates.

You may not even realise the economiser is there, but the truth is, when properly installed, it can cut energy bills from HVAC systems and drastically improve efficiency—according to a study from The University of South Australia.

There are a variety HVAC systems available on the market, such as dry bulb or wet bulb (single enthalpy and differential enthalpy), each with their own specifications.

Dry-bulb economisers, for example, sense only the temperature of the air but are less costly to install and maintain. On the other hand, wet-bulb economisers sense the temperature of the air, as well as the air’s moisture content. This therefore blocks excessive moisture from entering the building, but can end up more costly to install and maintain.  

Unlike many other parts of HVAC systems, the economiser is a relatively recent innovation that utilises outdoor air for cooling, coined ‘free cooling’.

‘Free cooling’ is the ability to cool without a compressor—one of the most expensive components of maintaining a building’s internal climate—and has been found to be very effective in climates similar to Adelaide’s.

Economisers are especially effective in facilities that require 24/7 operations, such as hospitals or other health care facilities. The introduction of outside air helps remove airborne diseases and keeps these environments fresh by minimising recirculation of stale air.

Australian climate varies and some economisers may not be appropriate for hot and humid climates in the north or west of the country. But if installed properly, it can reduce wear and tear on an HVAC unit.

Reduce HVAC load capacity

Minimising in load capacity is a pivotal feature in increasing efficiency of HVAC systems and refers to the amount of heating that a building needs, in order to maintain the desired temperature.

Ideally reducing load capacity is done through proper insulation of roofs, walls, pipes and ducts, but there are a number of other ways, including:

  • Proper insulation: building and envelope sealing and maintaining it yearly can increase energy efficiency.
  • Install energy efficient windows: Storm windows can help small businesses save, but need to be maintained by chalking, cleaning and replacing components.
  • Solar light: Another big issue when it comes to energy efficiency – window film can block up to 80 percent of solar heat by absorbing and reflecting the heat back outdoors so it’s important to have the right natural light balance.
  • Energy efficient lighting: lighting, especially older, less efficient models, generates heat. Upgrading to more efficient fluorescents or LEDs gives off less heat and reduces the strain on HVAC systems.
  • ENERGY STAR equipment: Old office equipment generates a lot of heat and upgrading to more energy-efficient equipment, especially those that are ENERGY STAR certified. Using this type of equipment creates easy ways to reduce load capacity. Rebates are available on many ENERGY STAR products.

Retrofitting and controlling

Another way of increasing HVAC efficiency and energy efficiency is through retrofitting. A good candidate for this is usually a well-maintained, energy intensive, large system that gets a lot of use.

But does retrofitting work?

A case study done by Department of Environment and Energy revealed that a retrofit on a Canberra building increased NABERS Energy Rating, lessened energy expenditure, increased the value of the building, and reduced greenhouse gas emissions by 70 per cent.

Retrofits are undertaken to put off total upgrades and can improve comfort with consistent temperatures.

This process is typically completed by replacing the compressor, adding condenser fan controls, and adding demand-controlled ventilation.

As part of a retrofit, it’s also important to consider adding programmable controls and a thermostat to increase HVAC energy efficiency, with an automated system that controls lights and temperature.

Through modern technologies, it’s possible to get a universal control panel that can be adjusted and automated to office schedules, meaning a lot of the energy savings can be automated when these other adjustments have been made.

Are you a facilities manager? If you want to learn more information on the latest development in HVAC systems and energy efficiency, register to attend Total Facilities at Melbourne Convention and Exhibition Centre from April 18-19. Click here to register for free.

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