Ventilation
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Continued push for good IAQ
Momentum continues to grow around the importance of good indoor air quality (IAQ). With an ever-increasing body of research confirming this, building owners need to make sure they’re providing an office environment that offers good IAQ. This will not only protect staff’s health but also help improve productivity, reduce sickness and even enhance job satisfaction. Allister Watson, senior product manager at Vent-Axia, tells us more on this research and how demand ventilation helps achieve good IAQ in the workplace
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mployers can see the benefits of a healthier, more productive workforce. To achieve this many larger companies are spending millions
on wellness programmes which include onsite gyms, health hotlines and meditation rooms. However a recent study by Harvard University, published in The Journal of the American Medical Association (JAMA), found that these programmes, offered by 80% of large US companies, have unimpressive results. A survey of over 1,600 North American workers, commissioned by the Harvard Business Review, found employees want the basics first: better air quality, access to natural light, and the ability to personalise their workspace. Fifty per cent of those surveyed said that poor IAQ made them feel sleepy and over a third reported up to an hour in lost productivity as a result. Good IAQ and light were found to be the biggest influencers of performance, happiness and wellbeing. Add to that, a workplace that provides these can see absenteeism reduce by up to four days a year. This research follows on from the publication of
the All Party Parliamentary Group for Healthy Homes and Buildings’ white paper ‘Building our Future: Laying the Foundations for Healthy Homes and Buildings’; the Government’s Clean Air Strategy; and the National Institute of Health and Clinical Excellence’s (NICE) draft Guidelines on Indoor Air Quality at Home, which all championed the importance of good indoor air quality. Modern airtight buildings pose a real issue for
good IAQ. Although highly airtight buildings are energy efficient, they are often less well ventilated and prone to the accumulation of air pollutants. Volatile organic compounds (VOCs), allergens and asthmagens originating from building materials, carpets, finishes, cleaning products and office equipment can all build up indoors to create a hazardous environment. Even exhaled CO2 can be a
problem, with research by the University of Wisconsin-Madison finding that levels of CO2 found in offices, classrooms and other spaces may have harmful effects on the body, including affecting cognitive performance. Airtight buildings can also overheat. Excessively high workplace temperatures impact IAQ and reduce productivity. Hot rooms are linked to fatigue, irritability, and headache. Chemicals are released from building materials faster when temperatures are higher, exposing occupants to higher pollutant levels. Unfortunately, it is not possible to solve IAQ
problems by simply opening a window (if it is not fixed shut). Although 60% of office workers say it is the first thing they do if they need ‘fresh air’, opening office windows can present further pollution risks by letting in outdoor toxins. So what can be done to solve this issue? Modern demand-ventilation systems are ideal in an office situation as they automatically respond to the air quality needs of a space, supplying or extracting air only when, and to the extent to which, it is required. This is in contrast to traditional fixed-volume ventilation systems which are either on or off, regardless of the conditions or the number of people in the room. Therefore demand ventilation offers better air quality in offices, as well as improved energy efficiency. Sophisticated controls and sensors enable demand ventilation to provide ventilation that is appropriate to the needs of the occupants. IAQ is continuously monitored by sensors which inform the main unit so it can adjust the ventilation rates accordingly. This means that the ventilation system is always running at the optimal fan speed, delivering the right airflow in response to the room’s climatic needs. Sensors can be combined to generate a hierarchy of control for the ventilation system and its operation can be easily linked to a
building management system (BMS) for full control and monitoring, if required. Therefore, only the energy that is needed to ventilate is actually used. The latest demand ventilation systems, such as the
Sentinel Totus 2 Demand Energy Recovery Ventilation system (D-ERV), offer energy recovery as well as optimal ventilation, with the Sentinel Totus 2 recovering 90% of energy that would otherwise be wasted. The system works by extracting the energy from the room’s warm, stale air before it is exhausted outside. It then preheats the fresh incoming air via the high efficiency plate heat exchanger before supplying the warmed, fresh air to the room. Even in winter, the incoming air is tempered to a level that should avoid draughts without the need for re-heaters. For the coldest weather, the latest systems now include frost heaters to provide a heating boost to achieve thermal comfort for occupiers. There are also D-ERV systems which offer a 100% summer bypass to help mitigate overheating in warmer weather. When temperatures rise the automatic summer bypass closes off airflow from the heat exchanger and opens a bypass that allows warm air to escape from the building. This allows the building to take advantage of any free cooling available when ambient temperature is below the room design conditions. A user-enabled night-time purge facility is another useful feature which can reduce the start-up loads for a building’s air conditioning plant, reducing overheating in summer from non-air-conditioned spaces. With the health, well-being and productivity
advantages of good IAQ now evidently clear, office building owners and managers should look to ensure that effective and efficient ventilation is included. The latest D-ERV systems are the ideal solution, providing an energy efficient and cost- effective way to ensure indoor environments remain healthy and productive, all year-round.
November 2019
www.heatingandventilating.net
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