Working with the environment and reclaiming energy that would otherwise be wasted are just some ways of achieving more efficient HVAC services. Richard Metcalfe of ICS Cool Energy takes up the subject..
According to the Carbon Trust, heating rooms and hot water can account for up to 60% of total energy usage in a business premises. Inefficient ventilation can result in around 30% heat loss in most commercial buildings, and air conditioning can increase energy consumption and associated carbon emissions by up to 100%. The good news is that there is a range of technologies that can improve energy efficiencies in buildings across the board.
Reducing energy consumption makes good business sense; it saves money, enhances CSR (corporate social responsibility), and helps with environmental efforts. There are five main technologies that will increase efficiencies in any business.
• Free cooling,
• Heat recovery,
• Adiabatic cooling,
• Turbocor technologies (the speed-controlled centrifugal compressor with magnetic bearings).
• Replacing harmful refrigerants such as R22.
|Adding free cooling to a chiller is an effective way of reducing energy consumption.|
Free Cooling is a fast and effective method of utilising low external air temperatures to cool the water used in HVAC (heating, ventilation and air conditioning) system applications.
The two main options available to achieve free cooling are, firstly, a chiller working alongside an independent free cooler, or, secondly, a chiller with an integrated free-cooling coil. Whichever method is used, both show benefits — including system reliability, cost reduction as the ambient air temperatures save on running costs and endurance, as there is less wear and tear on the chiller components.
Using external air, especially with the low ambient temperatures we have in Britain, companies could benefit from a reduction in energy costs of up to 70%.
Another method of maximising energy efficiencies is through heat-recovery technology. This offers an energy-efficient solution that allows chillers to operate at high efficiencies, whilst collecting and re-using its waste heat to provide heat for central heating or the domestic hot-water supply, for example.
Such units have the ability to cool a facility and recycle waste heat that would otherwise be expelled into the atmosphere. Recently we have worked with a health-club operator that used the technology to recycle and use the heat expelled from the air conditioning, to heat the club’s swimming pool.
Where businesses consume vast amounts of water for a variety of processes, it is important to seek alternative cooling solutions to reduce water use. Both adiabatic coolers and cooling towers can be used in the process of environmental and process temperature control — yet both are also very different in their operation, cost and physical footprint.
Adiabatic coolers are designed to pre-cool the air inlet stream into the cooling coils, whereas open-circuit cooling towers rely solely on latent heat removal during the evaporation of water for its heat dissipation. Adiabatic coolers consume 0.25% of the water in comparison to cooling towers, as well as having a third of overall running costs.
|Adiabatic cooling can considerably help heat rejection, especially when the ambient temperature is high.|
The coolers are designed to pulse as often as is necessary, greatly reducing water consumption and running costs. A UV system is supplied as standard which provides additional protection to further ensure that the mains water feed supplied to an adiabatic cooler is clean, killing over 99.99% of bacteria, as legionella is often a concern with cooling towers.
Turbocor technology is another way of saving money by creating more energy efficient processes. The Turbocor compressor operates without the use of oil, using digital rotor-speed control and magnetic levitation, and allows high part-load efficiencies to be achieved.
Even at very low conditions, a building’s energy requirements can be matched due to the inlet guide vanes which extend the compressor’s operational limits. The technology offers 60% higher ESEER values compared to traditional scroll or screw units, and reduced noise and sound emissions by approximately 8 dB(A).
Our own Turbocor unit is also a great replacement for existing units that still contain the R22 refrigerant. With less than six months to go until it will be illegal to use HCFCs such as R22 to service RAC equipment, we strongly advise businesses to consider which option they will pursue to ensure they are not caught out next year.
There are three main options. The most energy-efficient option is to replace with systems such as free cooling, heat recovery or Turbocor. The short-term fix will be to convert to a new type of oil or additional compressor. The third is to leave the system in place and deal with the consequences if units fail after 1 January 2015.
Whilst there are various options to ensure businesses remain compliant, it is important that a method is selected soon to avoid any pitfalls towards the beginning of next year.
Richard Metcalfe is sales director with temperature-control specialist ICS Cool Energy.