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HVAC Systems – The perfect prescription for buildings

In recent years, health and well­ness has become a top priority in nearly every facet of our lives, from nutrition to sleep and exercise. Yet a growing body of research demonstrates that health and wellness is not just about eating well and staying active; in fact, the environments where we live and work have a direct impact on our well-being, from our sleep/ wake cycles and mood to productivity and performance. Indeed, it is becoming increasingly important to place people at the heart of design and construction operations and development decisions.  Danny Packham, European Product Manager – Warm Air and radiant for Nortek Global HVAC UK Ltd, talks about planning a heating and ventilation strategy for the wellbeing of occupants

What do we need to consider when planning a heating and ventilation system for the wellbeing of occupants;

  1. Comfort of indoor environment 

The World Health Organisation defines health as “a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity”. As such the term “health and wellbeing” can be considered to cover social, psychological and physical factors. An individual’s health and wellbeing is determined by a complex combination of genetics, lifestyle, behaviour and environmental factors, including those related to the built environment. With the average person in the developed world spending approximately 90% of their lives indoors, the conditions and facilities that buildings provide and the behaviours that they encourage are therefore a significant influence on everyone’s health and wellbeing.

Indeed there is a large body of research that convincingly demonstrates that the design, construction and operation of buildings have a substantial impact on the health and wellbeing of their occupants.

Furthermore, the evidence shows that there is a clear difference between internal environments that are simply not detrimental to health and those that positively support and enhance health and wellbeing. For workplaces, where staff related costs typically represent 90% of operating costs (energy and rental related costs typically represent 1% and 9% respectively), anything that can help to make a workforce more healthy and happy can have significant impacts on an organisation’s bottom line in terms of improving productivity, absenteeism and staff retention/attraction.

The following aspects have all been shown to impact the health and wellbeing of building occupants and are therefore important building design, construction and operational considerations:

  • Indoor air quality and ventilation
  • Thermal comfort, temperature and humidity
  • Visual comfort, day lighting and artificial lighting
  • Noise and acoustics
  • Safety and security
  • Interior layout, active and inclusive design, and look and feel
  • Connections to nature (biophilia)

The importance of an HVAC system in commercial and residential buildings cannot be overemphasised, but is sometimes overlooked.  It is well known that outside air pollution is harmful to health and over the years a number of initiatives have been undertaken to improve and reduce these levels.  Unfortunately less attention has been given to indoor air quality as it is very difficult to detect, but get it wrong and it can have an impact on health and well being of the buildings occupants.

The biggest stride towards improving indoor air quality was the smoking ban, which was enforced in July 2007, but more needs to be done.

The fact remains that fresh air is good for the body, and in commercial buildings, it helps improve productivity. A good ventilation system helps to reduce the number of pollutants, bacteria and odour in a facility.  This is imperative considering we spend approximately 90% of our time indoors and indoor air environments can be as high as ten times more pollutant than outdoors.

A number of different types of ventilation systems are available, ranging from a simple fan only system right up to a packaged heating, cooling and heat recovery system.  However a good ventilation system will not only meet the ventilation requirements of the building but will also meet its temperature comfort conditions. This is where mechanical ventilation has its advantages as it can be combined with a gas fired heating unit (condensing models offer thermal efficiencies of up to 109% – net CV) to meet the winter conditions. Free-cooling, will in most cases, help to lower the space temperature when it creeps above the desired set-point, and for when those summer time temperatures cause the mercury to rise even higher, a mechanical cooling system will be necessary to improve comfort conditions for the occupants.

Mechanical ventilation can meet the above and more besides, the more air changes within a space will help improve air quality as fresh air, or air from another source, is replacing the air within. The number of air changes per area varies depending upon the functions carried out.

All of these options can be combined into a single piece of HVAC equipment that can also include air-to-air heat recovery via a thermal wheel. These allow the recovery of otherwise wasted energy exhausted from the building to be re-used, to pre-heat fresh air entering the building. This in turn will help reduce the amount of energy used to meet the heating demand of the building.

The Reznor RTU range is composed of air-to-air heat pumps, packaged with various heat recovery options and gas fired heating coils to maximise efficiency. All units are equipped with high efficiency G4 class air filters. Fresh air and ventilation options provide a high level of indoor air quality and help ensure a clean and comfortable conditioned space.

Control of your system is just as important as the HVAC system itself, a correctly selected system will maximise the performance, efficiency and comfort conditions within the building.

  1. Energy efficiency

Operating a HVAC system at optimum efficiency is a challenging endeavour. The number of set points, levels and feedbacks of boilers, chillers, pumps, fans, air delivery components and more can cause costly inefficiencies. Add to that the fact that weather variables affect the heat transfers in a building and increase loads on the HVAC.

Multiscroll technology combined with electronic expansion valves (EEV) and
EC plug fans increase the system energy efficiency and provide a resilient and reliable solution.

Due to the RTU’s ability to produce its output in smaller increments, spaces with
a variable occupancy rate and changing conditions during the day, such as shopping centres, can benefit from energy savings up to 30%.

  1. Improve indoor air quality

According to the Environmental Protection Agency (EPA), poor indoor air quality is among the top factors of environmental risk. Pollutants in the air can aggravate allergies and asthma in some people and cause dizziness and headaches in others.

Air quality depends on various factors.  Too many people within a poorly ventilated space will cause an increase in poor air quality.

Good levels of air filtration will help remove larger pollutant particles from the airstream and is necessary to maintain good levels of air quality.

Natural ventilation can improve indoor air quality by reducing pollutants that are present indoors assuming that those outside are in fact cleaner.

Humidification also plays a part in the improvement of air quality, particularly in environments such as hospitals. Humidity control is essential to many applications; from healthcare and labs to anywhere equipment productivity is vital.

Humidification units use the latest advances in technology to optimise the reliability and effectiveness. The systems are able to adapt to environmental changes and deliver on promises of energy efficiency.

Adapting to environmental changes and the need for energy-efficient systems. Vapac uses the latest advances in technology to optimise the reliability and effectiveness of all its humidifiers.

Bacteria and relative humidity

Relative humidity can be seen to have a similar impact on bacteria as it does on viruses, in that intermediate RH conditions have a considerable influence on bacteria survival, both airborne and on surfaces.  A high death rate of airborne pneumococci, streptococci and staphylococci is seen at intermediate RH levels.  Furthermore increased decay of a hospital strain of staphylococcus is seen at higher humidity levels.

Obviously, high relative humidity conditions are to be avoided; excessively high humidity (above 70%) is associated with mould growth and the multiplication of house dust mites, and these can have adverse implications for asthma and allergy suffered.  Mould, once established, will continue to grow even at lower humidifies and so continue to release musty odours.

As shown in the graphic below, the majority of adverse health effects would be helped by maintaining indoor humidity levels between 40% and 60%.  This would require humidification during winters in areas with cold winter climates.

Humidity control is essential to many applications; from healthcare and labs to anywhere equipment productivity is vital. Vapac, part of Nortek Global HVAC UK Ltd, offers a wide range of humidification products as stand-alone or OEMs, which use the latest advances in technology to optimise the reliability and effectiveness of all its humidifiers. These humidification systems adapt to environmental changes and deliver on promises of energy efficiency.

Humidity levels can cause fluctuations in a multitude of environments – the application possibilities are virtually limitless.

For further information on how to improve the environment of your occupants please visit www.nortekhvac.com/europe or call 01384 489700.


To have your industry news published in the pages of FMJ’s news section, Month in FM, and here online on fmj.co.uk, please send your news and image to Danny Grange danny.grange@kpmmedia.co.uk

The view or information contained within these unedited press releases, are that of the company producing it and not necessary the views of kpm.



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