It is now being recognized that Indoor Air Pollution can be directly impacted due to outdoor Contaminants. It’s now more important than ever to ensure that we protect Commercial Building occupants for Air Pollution which is estimated to be responsible for as many as 36,000 deaths a year in the UK, according to Public Health England.
Air pollution also costs our economy, mainly because of sick days and the additional burden on the NHS.
Whilst outdoor pollutants and Air Quality is being measured throughout the UK, little has been done as to what this means for the indoor environment especially as 80% of the workforce spend most of their time inside an office environment.
IAQ Now Linked directly to Ventilation in Buildings
The new Clean Air Act specifically addresses indoor air quality for the first time, making the health link directly to the ventilation in Buildings. Individuals would be able to take legal action if the Bill becomes law. This means that only a handful of Manufacturers will be able to Manufacture and Retrofit AHU’s for anyone designing ventilation systems for buildings.
ACP (Air Conditioning Products) have been at the cutting edge of AHU design, manufacture and Refurbishment for over 35 years so their experience and number of high end projects says it all
Many Building Owners, Managers and Occupiers are rethinking their approaches to Indoor Air quality, but now not only from a new equipment perspective, but what can be done with existing equipment. There are many possibilities where existing Air Handling units can be upgraded and enhanced to improve the Indoor Air Quality. (IAQ)
Not All Air Handling Units are the same
Modern AHU’s are simple systems with some standard components inc fans, heating and cooling coils, air filters, as well as humidification and possibly some sound attenuation. Also, due to ever increasing energy efficiency requirements, most new AHUs now incorporate heat recovery to reduce the amount of wasted heat, as well as EC fans and upgraded filtration. Retrofitting existing Air Handlers with many of these components can be achieved with relative ease and the benefits can be significant.
However not all Air Handling units are the same, especially those who are looking to win a project on price alone. Existing Air Handling units are coming in for higher levels of scrutiny because of their role between potentially highly polluted outside air and the indoor environment,
The design issue faced by specifiers of AHU’s is that smaller particulates can penetrate further into the human body. New higher quality filtration standards are focused on harmful particulates which makes. them more dangerous when inhaled.
This has impact on the design of the unit and the system as a whole, F7 filters are becoming a requirement in line with the international standards.
The need for heat recovery and higher specification filters means the AHU is subject to higher pressure drops, This can often mean that a larger AHU is required along with more fan power and, by default larger motors that consume more energy. This can be offset somewhat by incorporating EC fans. As stated before all of these items can be retrofitted into existing AHU’s.
Fan power is also specifically referenced in the revised ErP legislation and should not be ignored by specifiers and those who are looking for advice when looking to upgrade legacy systems. The legislation also requires multiple fan systems to build in redundancy, as well as improving efficiency.
Fortunately, a big benefit of EC fans is they are more compact than DC equivalents, which means they can help to reduce the size of the system and meet new energy targets.
The industry is highly competitive, however many suppliers cut corners to win the job on price and simply ignore the new standards which will be very difficult to police
Systems not fit for Purpose
The outcome is that building owners and occupiers pay more in the long-term and will be left with systems that are not fit for purpose, are not legally compliant and leave a legacy of poor performance.
It’s not difficult designing a system that meets the energy efficiency needs and IAQ needs without over-specifying on size and price. The application of good, basic engineering principles, including properly defining system – whether a refurbishment or new build.
Why not design a VAV system with 65% of design duty — rather than on 100% duty with 10% added ‘which is then having over-sized systems that can never meet their energy efficiency targets because they are too big. The better way is to allow operating for longer periods at lower duty. An over-sized system will cost the client more than if a properly sized system had been specified.
ACP provide technical innovations on new and refurbished AHU’s such as EC fans and Heat recovery Coils in order to minimize energy consumption. EC plug Fan retrofits alone can save up to 75% in Energy, with no more belts to change and improved speed control.
Various designs from Conventional layout, vertical and Adiabatic and Evaporative options are available.
Why not get in touch to discuss your next project.