UV lighting the road to recovery


12 August 2020
The ionisation effect takes place locally in the air flow managed by Aermec's FCZ H fan coil The ionisation effect takes place locally in the air flow managed by Aermec's FCZ H fan coil

Clifford Saunders, Aermec UK’s Senior Applications Engineer, explains how fan coils offering both comfort and sanitisation of indoor air can make workplaces safer.

The Covid-19 outbreak has made us all aware of the importance of good hygiene practices but it has also turned the spotlight on air movement and the health of a building’s occupants. We breathe in various types of micro-organisms all the time; many can be tolerated with no specific health care issues. But some viral infections such as SARS and Coronaviruses can easily spread and cause serious harm. One way of managing the spread of viruses is to inactivate them and break them down biologically and one of the most effective methods is the use of a UV lamp.

It has been well documented that effective ventilation can play a critical role in controlling airborne viruses in ventilated spaces. The UK’s Deputy Chief Medical Officer, Jonathan Van-Tam, explained the importance of ventilation in buildings: “There is a definite truism across all of the science literature that ventilation is a most critical part of reducing transmissions for respiratory viruses.” 

In the Unites States, ASHRAE created a task force to assess the effects of HVAC systems and the transmission of viruses in buildings, commenting that changes to a building’s operation could help reduce the risks of pathogen transmission. 

Researchers at the University of Oregon’s Biology and Built Environment Centre have conducted extensive studies and outlined a number of steps buildings owners can take to mitigate transmission and protect a building’s occupants, including exposure to ultraviolet light, which can reduce the ability of some viruses to survive.

Air purifying
The sterilising effects of ultraviolet light was first discovered in 1877 when the chemists Arthur Downes and Thomas Blunt showed that ultraviolet light had a destructive effect on bacteria.  Since then ultraviolet light has been used for sterilising water, germicidal lamps in food establishments as well as sterilising hospitals.

As well as Oregon University, The American Society for Microbiology (ASM) has also been examining the built environment and reported that UVC lamps can damage the DNA of bacteria, viruses and other pathogens, reducing their ability to survive. Its paper Novel Coronavirus (COVID-19) Pandemic: Built Environment Considerations To Reduce Transmission, published earlier this year also outlined the effectiveness of UV light in the built environment.

Viral particles are small enough to pass through traditional high efficiency HEPA and Minimum Efficiency Reporting Value (MERV) filters as the Sars-CoV-2 are between 80Nm and 160Nm (on average 0.1 microns), but they can be targeted by air purifying devices.

ASM also suggests that light could be part of a mitigation strategy as UV light has been shown to reduce the viability of viruses and UVC light and is already used for deep cleaning in healthcare settings.

Inadequate Indoor Air Quality (IAQ) poses a risk to the comfort of a building’s occupants but also their health - we are all familiar with sick building syndrome. Appropriate air management which ensures not only the comfort but the safety of individuals is vital to ensure the well-being and health of occupants.

Aermec is Europe’s largest manufacturer of fan coil units and, with its manufacturing base in Italy, the company is only too aware of the devastaing effects of Covid-19 across the country. Aermec responded by designing a dedicated range of fan coil units, which can address hygiene concerns by sanitising indoor air and help to make workplaces as safe as possible.

The FCZ H fan coil incorporates a UVC germicidal lamp with a Titanium Dioxide surface

Sanitising benefits
It latest FCZ H fan coil is a dual-purpose solution that provides comfort and sanitisation in one unit and is suitable for retrofits depending on the spatial limitations. 

Covid-19 has focused awareness on the importance of indoor air quality. Italy was hit particularly hard by the virus. The FCZ H offers a solution that provides comfort whilst the sanitising action of the photocatalytic system helps to limit the spread of infections.

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Based on Aermec’s flagship FCZ range of fan coils, the FCZ H cooling capacities range from 0.8kW - 8.6kW and heating capacities from 2kW – 17.1kW. It combines quiet operation, low electricity consumption and reliability with the sanitising benefits of an integrated photocatalytic system.

Numerous studies confirm the effectiveness of photocatalytic devices can make legionella, fungi, mould and other virus bacteria such as flu’ and SARS inactive.
The unit incorporates an Ultra Violet C (UVC) germicidal lamp with a Titanium Dioxide (TiO2) surface. When radiated by the lamp, any pollutants in the air flow are broken down into harmless substances by the free radicals created by the UVC and the TiO2 surface. The UVC lamp is shielded, so the device is harmless and has no effect on people in the room.

Titanium Dioxide (TiO2) possesses a high degree of thermal and chemical stability.  It is not toxic for humans and is widely available, bio-compatible and highly sensitive to UV light.  The catalyst which resembles a honeycomb, increases the photocatalysis reaction surface, which maximises and guarantees system efficiency. The interaction of the catalyst with the UV light (photocatalysis) creates an effect that attacks, breaks down and eliminates the polluting agents.  

Aermec is planning to roll out UV lamps across its heat recovery ranges

Maximising efficiency
Over 90 FCZ H units have already been sold for a major office development in London, and the units are also being used in a number of hospital projects. The sanitising benefits make it an ideal solution for any indoor places including nursing homes, laboratories, pharmaceutical companies, hotels, schools, beauty salons, office buildings and any other building requiring guaranteed hygienic air flows.

The FCZ H fan coil unit offers maximum comfort and safety, with minimum operating noise – it is the quietest Eurovent certified fan coil on the market with noise levels down to 23dB(A).

Environmental issues have been addressed by reducing the power consumption down to four watts and avoiding the use of refrigerants in indoor ambients. Installation and maintenance activities have also been simplified to reduce operating costs and maximise efficiency. The air filter is easily removeable for cleaning. 

Options include:

  • Three speed AC motor or infinitely variable EC motor for optimal sound and energy performances
  • Two or four-pipe systems
  • Fixed and adjustable grilles with CFD optimised air flows
  • Pressure independent valves ensures constant water flow in all conditions
  • Easily removable G2 air filter
  • Wall mounted or wireless remote controls

Manufactured using a polyester powder-coated galvanised steel housing, the absence of unpainted surfaces on the FCZ H reduces corrosion risks. The fan coils can be floor or wall mounted units as well as ducted or recessed depending on requirements, addressing a variety of installation requirements. As with Aermec’s other fan coil units, depending on spatial limitations the FCZ H can also be used for retrofits.

When it comes to Covid-19 there are many questions unanswered, how the virus spreads and the role that HVAC systems can play. There have been numerous papers published since the outbreak but no reports of transmission through HVAC systems. Building owners can help minimise the spread through the cleaning of air by using a UVC light and photocatalytic oxidation equipment which can inactivate and reduce the amount of microbiological contaminants.

Aermec is planning to roll out UV lamps across its heat recovery ranges. This is a key priority for the company in a bid to help customers improve the quality of their indoor air and minimise the risks of infection.