Companies are now realising that high temperatures in the workplace are affecting staff moral and productivity, says Mike Sullivan, MD of CoSaf Environments. They are now faced with the conundrum of how to reduce summer temperatures cost-effectively without increasing their carbon footprint
A growing number of reports becoming available from studies into the effects of Indoor Environment Quality (IEQ) and Indoor Air Quality (IAQ) show that worker productivity in factories and offices is significantly affected by the quality of the indoor environment.
Temperature, of course, is one of the major factors, and workstation temperatures that exceed about 25degC affect productivity by about two per cent per degC above that. Many industrial buildings, factories and warehouses, workshops, etc. suffer from poor ventilation: hot air is trapped inside, leading to high temperatures, especially during the summer months when at midday, the sun’s energy is equivalent to 1000W per square metre. Poorly insulated roof spaces quickly heat up to in excess of 60degC, which in turn heats up the structure below.
Many of those same reports, along with others that deal with specific quality issues such as ventilation rates and pollution, show that these issues significantly affect worker health, productivity, morale and absenteeism.
Legal protection
Faced with decreasing productivity in summer, and with the spotlight on their indoor working environments, companies are now looking for a solution to the problem urged on by the TUC, which wants a maximum working temperature of 30degC or even as low as 27degC for those doing strenuous work. It is also striving for legal protection for workers of an enforceable maximum workplace temperature, stating that there is no logic for having a minimum temperature but no maximum. However, while companies are now waking up to the need for cooling they are also aware that if they exceed their emissions limit they will be penalised. With heating, ventilating and air conditioning being a major user of energy and a major cause of carbon emissions, companies are seeking ways of not only cutting down on carbon discharge but also of reducing energy costs that continue to rise.
Providing cooling for workers in industrial environments to improve productivity and reduce absenteeism from heat stress has previously been perceived as financially prohibitive. Instead, companies have chosen to reduce heat and humidity by opening windows, using fans or creating airflow through exhaust ventilation or air blowers. Whilst in some cases this has gone some way to improve conditions, most workers report that such measures have made no marked improvement on their working environment.
Now, however, companies are realising that evaporative air conditioning systems, such as Breezair from Seeley Int., are the answer to their cooling problems. Not only does evaporative air cooling provide a cost-effective solution to indoor cooling and indoor environmental quality, but also costs a fraction of the price of air-conditioning to install and operate. Evaporative cooling can be utilised to 'spot cool' specific areas or cool a complete building, decreasing ambient temperatures by around 8degC, replacing stale air with fresh air and filtering out debilitating pollutants - and all achieved with one simple set of equipment. It can also have a marked effect on a company’s bottom line by increasing productivity, reducing workstation temperatures, increasing machine efficiencies, decreasing absenteeism from ill health and decreasing workplace accidents.
Avoiding the use of HFCs
Evaporative air cooling is not only emission-free, but is cheaper to run than refrigerant-based air conditioning. It provides excellent cooling properties and ventilation with minimal energy consumption, using water as a working fluid and avoiding the use of global warming HFCs. Evaporative air cooling technology is simple, functional, can be used in both industrial and commercial applications and consumes less than a quarter of the energy of refrigerative air-conditioning systems.
Industrial ventilation is particularly demanding because it must provide an environment in which both the workforce and the product is free from harmful contaminants. It is not sufficient just to ensure an acceptable average freshness of atmosphere throughout the area: ventilation must also take into consideration the number of air changes required. Mechanical ventilation brings about positive air movement along desired air distribution patterns and a more uniform control of the environment within an area.
When minimum ventilation rates (air change rates) are set as part of building regulations they do not account for the local climatic conditions. Evaporative cooling systems do not just ventilate but they cool at the same time. They are specifically designed for each application on the basis of the local climatic conditions. Often this requires a higher air change rate than the minimum specified. The effect of this higher airflow is not only to greatly improve the air quality but also to provide much needed temperature reduction in hot weather.
Whilst many companies are aware of the need for ventilation to improve air quality, they may be unaware that evaporative cooling combines cooling and ventilation in one versatile appliance. For just an additional 20 per cent more than the cost of a standard ventilating system, industrial and commercial companies are able to install an evaporative air-cooling system which will improve working conditions, thereby helping to increase production, decrease downtime and improve staff morale.
Control mode options
Evaporative air cooling systems such as Breezair, have wall-mounted climate control panels with control modes. In Auto mode they monitor the temperature and personal comfort setting, automatically increasing or decreasing the fan speed to maintain comfort. Fan speed can be varied manually in Manual mode and the system can be programmed in Timer mode to be switched on and off within a 24-hour period. The cool/vent mode gives the simple choice of operating the system as a cooler or ventilator as required. Within industrial environments this means that winter ventilation can still be used to remove vapours, odours and/or heat.
Harnessing the natural evaporative process efficiently is where the real science lies behind the successful commercialisation of evaporative cooling and ventilating. Direct evaporative air coolers with a saturation efficiency of at least 80 per cent can easily cool buildings from about five to 12degC below the outdoor air temperature, depending on the climatic conditions. Refrigerated air conditioning can achieve the same, but is unable to provide a through-flow of healthy fresh air and ventilation - and will cost substantially more to install and run.
