Mike Sullivan, business development director of CoSaf Environments, explains evaporative cooling and tells Paul Braithwaite why the installation and running cost are hot news.
Mike Sullivan of CoSaf Environments, will not sell an evaporative cooling system if it is not right for the project.
He adds quickly he does not find many circumstances where an evaporative cooling system will not work but there are occasions when other forms of cooling might be more appropriate.
CoSaf is the sole supplier of the award-winning Breezair evaporative cooling system for the UK and Ireland. The Breezair brand is owned by Australian company Seeley International, which claims it is world leader in evaporative coolers. Evaporative cooling is a most efficient and environmentally friendly way of providing mechanical cooling while maximising free cooling at all times.
Sullivan suggests evaporative cooling is all about comfort cooling at a very basic level although at a higher level this can mean healthier employees and, consequently, more productive staff.
And it is not just about cooling warehouses and industrial premises. When the company first took on the development of the evaporative cooling market, the main thrust was providing systems in existing buildings- with some significant success. He reels off the names of blue chip manufacturers and suppliers such as JCB, Patak's, Haribo, Heinekin, Quinn Group, Mclaren; the list is endless.
But, having built its base, the company increasingly designs for new buildings which are crying out for a greener cooling solution. In line with the latest regulations buildings are becoming tighter.
'Traditional green cooling solutions would be natural or mechanical ventilation but with modern construction practices maintaining comfort is increasingly difficult necessating mechanical cooling. Until CoSaf came on to the scene, the only practical solution was air conditioning.
But, Sullivan insists, any area which needs a degree of cooling, such as schools, colleges, fitness centres, care homes and offices, can use evaporative cooling.
'Take for instance colleges with areas of high occupancy. Breezair can provide both fresh air requirements to meet BB101 and mechanical cooling to maintain comfort. Often the cost of installing and running air conditioning is prohibitively expensive'
Lots of glass
He cites Stockport College where the architect has used lots of glass and together with the high occupancy created a need for mechanical cooling. Specified by the consultant the cost of installing Breezair units there was 50% of that of a VRF system. The other big plus is that the running costs are a mere 15% -20% of the cost of running air conditioning with minimal environmental impact.
The latest Breezair Icon models consume less than 300kW/hours a year in the UK and are the most advanced and efficient evaporative cooler in the world. The Icon would easily cope with a classroom, for instance, as it offers a true 15kW of cooling and would cope with about 200m2 of space. It runs on single phase electricity.
'If the external temperature were about 200C in the UK, a 50 drop can be achieved, which is often enough for comfort. As the external temperatures go higher, there is a bigger drop which allows us to maintain the cooler temperature in a building.'
Sullivan adds it is inverter driven so the fan will run as fast or as slow as necessary and will always maximise free cooling. However, he maintains air conditioning will guarantee a fixed temperature. Evaporative cooling will not.
'We can ,with evaporative cooling, guarantee the temperature will be within a band of 20 - 240C.' His argument is that if the inside temperature is 240C, then the outside temperature will be plus 300C and this, he insists, is comfortable. He adds it is about getting away from 'a comfortable temperature of 210C'. 'People are comfortable within a wide range of temperatures.'
What Breezair units need is ventilation.
'Because we drop the air temperature but raise the relative humidity, we will always need the air to escape. If doors and windows cannot open then mechanical ventilation is necessary.'
He cites the retail environment where customers are always coming in and out of the store and this is sometimes enough ventilation. Breezair units have also been used in a number of shopping malls. Projects have recently been completed in Widnes and Warrington shopping centres.
Cool malls
Air is drawn in through roof vents, ducted to the Breezair units and forced out to cool the malls. More mechanical vents in the roof allow the hot air to escape. 'Before we installed the cooling units, shopkeepers and stallholders were complaining flowers and fruit were wilting in the heat.'
For Sullivan fresh air is the key. CoSaf has recently installed Breezair units on the top floor of its own offices. 'Fresh air coming in means the CO2 is driven out, making for a more invigorating environment.'
He adds this is a big selling point. Again, humidity is often misunderstood. Dropping the temperature and raising the humidity has no detrimental effect on staff or customers. Just the opposite in fact. ASHRAE has produced a comfort-zone chart.
'Most people are comfortable with 22 - 290C and 20% to 70% RH, but this is across the world. UK figures are at the lower end.'
And, he insists, Breezair will always deliver within this area. 'People can be comfortable in a relative range of temperatures.'
And evaporative cooling can be used in conjunction with renewable technologies. Sullivan has been tendering for jobs where the Breezair units will provide the cooling and biomass boilers will be used for heating.
At Stockport College Breezair units are used to cool and ventilate the classrooms in the summer. In the winter the water is switched off and the units bring in fresh air only although this fresh air is warmed by batteries in the ductwork from the biomass boiler.
And The Carbon Trust has approved the technology so grants are available. There are two main units available in the UK, the Icon and the TBA. A third, the RPX is, says Sullivan, 'a big beast' delivering around 9m3/sec. Plus there is a mobile unit which is distributed through various hire shops.
The Icon is the most efficient using only 100W on its lowest setting. It is also the quietest evaporative cooling unit in the world, he says. Many homes in Australia use Breezair evaporative cooling rather than air conditioning. And, of course, evaporative cooling is only needed when the temperature reached a certain height.
Sullivan says some 50,000 Breezair units are sold each year into more than 60 countries. The potential is huge and with some exciting developments on the way CoSaf has all to play for.
Sullivan can see the potential for a UK domestic new-build market as houses become tighter.
However the company is focused on the specifier market for the foreseeable future as well as continuing to cover and support the end user sector it has already carved out for itself.
One success for CoSaf was a retail store. The consultant was set to install about 12 air conditioning cassettes but changed his mind and specified Breezair units.
The cost of the air con units for this particular project would have been about £50k - £60K with running costs of £6,000 per year (over 39 weeks of the year). The store eventually installed six Breezair units which operated in conjunction with four extract air fans. The capital cost was £35K and running costs are less than £1,000 a year. This resulted in a capital saving of 40% and 85% saving on the running costs.
And there is no fear of legionella. The Breezair unit is connected to the main cold water supply, the water is always less than 200C, there is no storage and it will not create a aerosol or mist.
The Breezair units have been tested to VDI 6022, the European Air Hygiene benchmark.'
The units should be maintained every six months. CoSaf has its own maintenance engineers and sub contractors who have been trained on the units. The company offers installer training too.
'We are the sole supplier. We will not supply units to contractors who have not been through the training course. Our reputation is at stake.'
That said, Sullivan says CoSaf installs some 60% of the units it sells. It also undertakes end-user training as it believes it is vital they understand how the units work. It has four staff designers who offers full design support and assistance.
The company was started 1991 by Bob Sullivan, Mike's father and is now owned by Mike and brother Karl. Currently turnover is £3.5M but Mike expects this to increase to £10M within five years and this in spite of the recession, 'or perhaps because of it', as people become even more aware of energy efficiency, he insists.
How evaporative cooling works
The ideas is simple and Mike Sullivan quotes an example:
“On a hot day it is cooler on the coast because, as the hot air passes over the sea, the heat causes the moisture to evaporate. As the moisture evaporates, it takes the heat-energy out of the air.
The Breezair unit works in the same way.
Warm ambient air is drawn into the Breezair unit through a large wetted membrane. The unit is connected to mains cold water which runs over the membrane. The water absorbs some of the heat by the natural evaporating process. The cooled air is then blown out into the room. The combination of a reduced temperature and constant airflow produces a more comfortable working environment.
The idea is not new. Thousands of years ago, the Arabs used to hang wet blankets over the entrance to their tents. The warm air passed over the blankets and cooled the occupants of the tents.