Refurbishment that can reduce energy consumption by 75%
Exploiting the renewable-energy benefits of heat pumps — Philip Ord.
The last 10 years have seen the efficiency of heat pumps for air conditioning improve so much that refurbishment becomes extremely cost effective. Philip Ord describes how.As we leave the coldest months of the year behind and (hopefully) head towards a warm spring and pleasant summer, many systems used to heat and cool our buildings will be ready for their regular annual check up.
Benefits But whilst your system may have served you well for another year, are there cost and environmental benefits in taking the plunge and replacing it for a modern heat pump system? Climate change is an accepted reality by all but the most hardened cynics, but whether you subscribe to the green arguments or not, there are huge financial benefits to be made from examining your building’s energy use and finding ways to cut consumption. For those involved in maintaining a building’s services the million-dollar question is: ‘When is it better to replace rather than repair?’ Regardless of the size of your building or system, there is never really an ideal time to rip out old equipment and install new because of the potential disruption and downtime, but the financial and environmental arguments for upgrading old and relatively inefficient plant now demand that you should at least consider this option before simply renewing that maintenance contract. Heat-pump air-conditioning systems have come on in leaps and bounds in the past few years. So much progress has been made in making equipment more efficient so that a 10-year-old system will be around 75% less efficient than the modern units available today.
Dramatic cuts With the rising price of energy, you can make dramatic cuts in your fuel bill with figures like that. Heat pumps are movers of heat energy, and a modern system can offer simultaneous heating and cooling and transfer energy around a building to balance requirements. In a perfect scenario, the cooling load for a densely populated area in full sunlight can be offset by a section that needs heating. Some units that can take any excess heat and use it to provide hot water. Heat generated by the cooling load for a gym, for example, can be converted into hot water for a swimming pool. In a restaurant, the diners can be kept cool and the excess heat can be transferred into hot water for the kitchen Modern VRF air conditioning is also slowly winning the arguments against gas and chiller systems as well by being more effective overall at providing year-round combined heating and cooling. Year-long tests we conducted at our Hatfield office using a ground-source heat pump VRF system demonstrated that it is more than £15.59 cheaper to run per square metre per year than a chiller/boiler combination. This saving is based on average fuel prices last autumn, so the gap will have grown even bigger by now. What I also found very interesting in the tests is that normal air-cooled VRF systems work out at around £14/m2 cheaper to run per year when compared to boiler and chiller, producing over 1900 kg less carbon-dioxide emissions per year. You do not have to be a world-class mathematician to see that with figures like these, the capital costs for a new system can be recouped within years rather than decades.
Corporate reputation The environmental benefits also enhance an organisation’s corporate reputation. Not only can an organisation demonstrate a reduction in energy consumption (and lower carbon-dioxide emissions at the same time) but the replacement of an older air conditioning system also removing harmful R22 refrigerant. For those still unconvinced that all these benefits are worth the disruption, there are also systems available that can reuse the pipes and wiring from old air conditioning, which can mean an installation can be replaced in days instead of weeks. Again, there are both environmental and cost benefits. Saving money on the installation by reducing the time and materials needed also means less raw materials being used in the first — such as copper piping. If existing pipes can be simply cleaned, pressure tested and reused, there are significant environmental implications for production globally.
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At Mitsubishi Electric’s own premises in Hatfield, ground-source heat pumps have reduced annual running costs by well over £15 per square metre per year compared with a chiller/boiler combination. |
Even if you decide that now is not the time to replace old equipment and that your kit will serve you well for at least another year, you can still help save the planet by simple things such as dusting internal vents and clearing outdoor compressors more often. Air conditioning works much better and much more efficiently if it does not have to suck or blow air through a pile of leaves or dust. Whether or not you are looking to replace your equipment, simple maintenance has an important role to play in reducing energy consumption to save the planet whilst also helping to significantly reduce your energy bills. That has to be worth considering.
Philip Ord is product marketing manager for Environmental Control Manufacturer, Mitsubishi Electric. The company’s Green Gateway Initiative points the way towards a reduction within our built environment of 3 Mt of carbon dioxide per year by 2016.
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