All buildings consume energy and the more we regulate both internal air quality and energy consumption levels, the more building users will demand equipment and services that can satisfy both modern living and environmental concerns. Is there a way to minimise the impact of a building’s services yet still provide the levels of comfort and control expected?
You would expect me to say that air conditioning is a necessary fact of life today in the commercial built environment but with modern equipment able to heat, cool and ventilate whilst providing energy efficiency levels that rival or exceed alternatives, I do believe there is a very strong case for VRF air conditioning in the majority of applications.
However, we realise that despite the benefits of air conditioning it does consume energy. In fact we have calculated that, each year, the splits and VRF air conditioning sector in the UK could account for up to 1,600,000 tonnes of CO2 emissions for cooling. Even with increasing efficiency levels and product advances, this figure could still increase to around 2,400,000 tonnes of CO2 per annum by 2016 if current behaviour isn’t changed.
But we cannot really go back to the days before mechanical heating and cooling, and natural systems struggle to cope alone with all the conditions that the UK can throw up (even in a single day) and still match legislation governing air quality and internal temperatures, let alone the expectations of modern consumers.
What we can do though, is only fit the right equipment for the right application, correctly specified and properly installed and maintained so that when it is working, it performs in the most efficient ways possible.
The need to change
Everyone accepts that we must do something about energy consumption, with figures showing that 50% of CO2 in the UK are attributable to the built environment and over 27% come from the energy we use in our buildings. The UK is now also a net importer of energy which makes us a hostage to global fortunes.
Politicians have also realised the need for change and set a raft of tough targets that will require a fundamental rethink of the way we use energy within the built environment. So there is a pressing need to minimise energy usage for political, economic and environmental reasons, but there are also compelling financial benefits for building operators who find ways of minimising energy consumption spent on heating and cooling.
This is where I truly believe that heat pumps can offer real hope. With advances in the technology delivering performance and efficiency levels that simply weren’t possible even five years ago. Modern heat pumps have advanced over recent years and for heating, they can now outperform an equivalent gas boiler by at least 3 to 1.
The system uses the thermodynamic properties of refrigerants and in order to absorb heat from one place and release it to another, we utilise the ability of the refrigerant to boil from a liquid to a vapour and its capacity to condense back into a liquid.
We have conducted extensive tests at our Hatfield offices which clearly demonstrate that a VRF ground source heat pump air conditioning system is much more effective at heating and cooling a building than the traditional method of using a boiler in the basement to heat and a chiller system on the roof to cool.
The heat pump system is able to move energy around the air conditioning’s refrigerant circuit to transfer heating or cooling and offset the energy required for one against the other, thereby reducing the overall energy consumed.
The results also demonstrate that the much more common air source VRF heat pump air conditioning system is also much more energy efficient and cost effective than the traditional method.
And this is just the start of the process of advancement, as we are now seeing heat pumps coming into use in different ways in new sectors, such as the example in the sudden growth in heat pump air curtains.
These act as an important, energy-saving measure for retail outlets and buildings with heavy footfall through their doors.
Recent advances in VRF heat pump air curtain technology has led to the development of new models which require less than a third of the power of an equivalent direct electric heated air curtain and so are considerably cheaper to run whilst reducing emissions by around 67%. These transfer excess energy generated from the building’s air conditioning, to the air curtain, thereby saving on the amount of energy needed here.
Commercial water heating
Another area where VRF heat pumps are proving their worth is in the area of commercial water heating which, again, is not something that would even have been imagined ten years ago.
We now have data from live trials of our own PWFY water heating system that prove that is far more cost effective and produces far less CO2 emissions than traditional methods of water heating with demonstrated savings of 78% in both running costs and emissions over the previous system.
These trials were conducted in the real world of the busy kitchen in our Hatfield offices and show that the unit, which is able to use excess heat recovered from a VRF air conditioning system, costs less than a quarter of the running costs than the previous gas boiler system and about half as much as a modern gas condensing boiler system.
The water heater has been supplying all of the hot water required by the three-storey building’s busy kitchen, which serves a 100-seater restaurant offering cooked breakfasts and lunches five days a week. The system outputs water up to 70ºC and we now see the potential for companies to effectively receive all of their hot water for free!
A serious alternative
Products like these are available right now and these systems offer a serious and viable alternative to both commercial and residential gas boilers. We can also expect the efficiency gap and the cost benefits to increase even more as the price of gas and oil continues to rise.
As an industry, we simply must find more energy efficient ways of providing the comfort levels for our buildings that modern life and legislation demands, if we are to get anywhere near the emissions reductions targets for the UK that the Government has set.
With heat pumps I believe we now have a real and tangible way of moving forward towards meeting these targets. The added advantage as well is that heat pump systems can also save businesses money by reducing their fuel bills.