With new buildings becoming increasingly airtight, the task of effectively ventilating them has taken on new meaning.
Increasing focus on, and recognition of, the retrofit market has introduced further factors. While advances in technology offer ever more effective solutions, these need to be carefully considered and applied.
Xpelair Ventilation Solutions head of marketing Steve Mongan says the impact of Part F 2010, coupled with an increased emphasis on SAP Appendix Q, is pushing the market towards whole-house ventilation systems. Energy-efficient MEV and MVHR ventilation systems are becoming the only types that can ventilate adequately and still meet Target Emission Rates (TERs).
As these systems need a certain amount of ducting, they are only really suited to the new-build marketplace, says Mr Mongan. They should only be used in refurbishment when ducting can be installed without restrictions.
These systems are also suitable for the commercial sector as well, he continues. MEV systems are often used to ventilate toilets in hotels, pubs and schools, while MVHR solutions are used in offices to provide measured intake and extract air flows. It is therefore essential that the benefits of this technology are understood.
One of the latest developments is EC (electrically commutated) motors. Manufacturers are now moving to EC motors because they consume even less energy than DC versions, as they have all their electronics built in. This negates the need for an external power-consuming transformer, helping to ease the installation and maintenance processes.
Heat recovery cells have also been developed that can recover up to 95 per cent of wasted heat. Recovering this and delivering it back into a dwelling will have significant benefits on an end-user’s energy bills, says Mr Mongan.
Airvent fire engineering director Ian Doncaster highlights the need for smoke control and ventilation equipment installers to be more involved in system design.
This will avoid plans not matching reality. It can happen more easily than you might think and not only add time and difficulty to your work, but can impair the life safety functionality of the products to be installed, he says.
The issue is simple: specification is generally set at the early sales stage and often not formally amended before the final stages of a project, although architectural design changes and builders’ practical interpretations are bound to take place.
By the time the smoke control installer arrives to find the site not as expected, he is often jostling for working space with others. By this time it’s too late to make timely adjustments and ensure final sign-off.
The solution is project management. A strong, experienced team is required to sell the correct solution, develop it through the life of the project, deliver it on site and commission it. The key is to make site visits, take measurements, speak to other contractors and learn what important changes have been made and why.
Smoke ventilation systems are becoming increasingly sophisticated and need to be integrated into the building design rather than applied at the final stages to meet legislation. At commissioning and handover, a thorough understanding of the legislation is necessary to make any modifications to cope with natural evolution in the build process.
Breathing Buildings managing director Shaun Fitzgerald says it is important to consider how to cut energy consumption. He notes that 50 per cent of carbon emissions are caused by buildings, 25 per cent by transport and 25 per cent by industry.
‘Greening’ a building can make a significant impact. The first thing to do with an old building is insulate it, after which solutions such as low-energy lightbulbs and natural ventilation should be considered, then renewable ways of providing the building’s energy.
Unfortunately, too often people jump straight to how the power is generated, says Mr Fitzgerald. Making a new-build airtight and well insulated can be relatively easy and natural ventilation becomes quite simple to incorporate into the building.
If you have done a good job of insulating the building and keeping heat in then you can start working out the best way to use it in winter and release it in summer as required. Creating an airtight building does not fly in the face of building a well-ventilated structure.
Airtight means you can ventilate the building when you want to and that gives you controlled ventilation. Making a building airtight is the best thing you can do in addition to improving the insulation levels, he says.
If your building is leaking like a sieve, then your heating bill cannot be reduced through natural ventilation, although summertime overheating can be alleviated. Being clear about when natural ventilation is suitable is crucial, Mr Fitzgerald concludes.
Oh the humidity
HygroMatik business development manager Andy Chessun (pictured) says the necessity for humidification equipment to meet the requirements for controlled humidity and optimum air quality has long been recognised within specialist environments, such as museums and hospitals.
There is now an increased awareness within other areas, such as the workplace, to install humidification equipment for increased optimum air quality and an improved ecological footprint.
An individual can become more susceptible to illness if the ambient relative humidity is below 40 per cent rH. Dry air is one of the main causes for respiratory infections as dehydrated skin and mucous membranes will become unable to effectively fight intrusive viruses and harmful bacteria.
Combating poor air quality is relatively simple and can benefit a working environment in terms of efficiency, cost and eco-awareness, says Mr Chessun.
Humidification equipment can easily be added to an existing air conditioning unit and the recommended equipment for a retrofit would be an adiabatic high-pressure or low-pressure system. The water is finely atomised and introduced into the air without the need for thermal energy from an external source.
Heat is produced from the air to transform the water into a fine vapour. The process will also cool the air and this increases the overall efficiency of an air conditioning unit. An optimum quality adiabatic system has the potential to save up to 30 per cent cooling capacity during summer.
The high-pressure system produces a fine water mist without any standing water or the need for chemicals. The low-pressure system operates with a water lubricated pump that can last up to five years, making it oil-free, clean and safe. Both systems humidify with demineralised water and this avoids calcium deposits and reduces the need for maintenance.
Introducing an adiabatic system is a simple and cost-effective way to update an existing air conditioning unit to create a healthier and ecological working environment, Mr Chessun concludes.