Covid 19 – keeping your building safe

Air conditioning and ventilation filtration, induct UV and room UV treatment at these unprecidented times is key in keeping a cleaner air quality to protect yourself and your staff.

We have experienced a higher demand for advice and guidance relating to air conditioning and ventilation systems. The most common question being asked is “How do I ensure the best quality air from our office, retail, gym, hotel, restaurant, bars, Cinema and Theatre systems”.

The key to ensuring better air quality, is a higher grade of filtration, UV treatment, ductwork cleaning, testing and preventitive maintenance, which inturn ensures, cleaner systems with better air quality, giving your staff and customers peace of mind within their environment.

It doesn’t stop there. If you have been away from your office for a prolonged period of time have you given consideration to your drinking water. If left dormant for over 14 days bacteria can build up and lead to legionella. We can also provide water sterilisation solutions.

Please click below to view our current heating, ventilation & air conditioning (HVAC) solutions:

Air Handling Units (AHU) & Heat Recovery Units (HRU)

Air handing and heat recovery units are the systems that bring fresh air into our office environments which are fitted with filters. Normally these filters are classed G as a standard filter and all units are fitted standard with this class of filter unless requested to be different.

All manufacturers offer a range of filters that can be fitted to AHU’s and HRU’s which are rated higher than the standard filters at M6, F7 & F8.  Increasing the grade of filters fitted to AHU’s, HRU’s and primary supply ducts entering the floors will provide a greater level of safety to your staff, customers and yourselves. All different grades of filters can be manufactured & installed, we would welcome the chance to discuss this in more detail with you.

If there is no access available to the AHU at roof level, we can offer the bespoke supply and installation of a primary supply filter, this is installed where the supply duct enters the floor.

For this type of installation, we would recommend the following filter : F7 DualFlo Filters

The F7 DualFlo filters have a high surface area of filter media giving the following advantages;

  • A low initial Pressure drop (Pd) over the filter
  • Due to the low Pd there will be little effect on the energy consumption of the fan system
  • There will be a longer lifetime of the filter due to the large surface area of filter media
  • Easily retrofitted into HVAC systems without major disruption to the design of the existing system.

The advantages listed above mean that not only are you supplying safe air to your staff and customers but are also reaping the benefits financially;

  • Energy consumption has not increased with higher grade filter
  • No major costs for installation
  • Cleaner air in your office space could reduce the amount of sick days

DATA AND PRODUCT SHEET FOR F7 DUALFLO FILTER: click to view in a new tab.

DATA AND PRODUCT SHEETS FOR F7 DUALFLO FILTERF7 DualFlo High Efficiency Filter (DFM7) Filtration Categorisation



Fan Coil Units (FCU’s)

Just as AHU and HRU’s, fan coil units are also supplied with standard G class filters which can be changed for a higher grade Hepa filter. Everyone is trying to protect their staff and customers from air entering the building through the ventilation systems but forget that people are walking into offices with common colds, flu and viruses that can become airborne and affect others. We therefore recommend the installation of a Hepa filter to each fan coil unit that can catch these particulates before they circulate further.

As with AHU’s an Increased filtration grade of filters can be manufactured and installed to FCU’s. (Filter class table can be found below).

We recommend the following filter is fitted to the fan coil units : HEPA Filters

  • H13 grade is a hospital grade level of air filtration (99.95% at 0.3 micron) so offers a high level of protection against contamination and bacteria
  • The HLFM13 68mm Laminar Flow HEPA filters, have a high surface area of filter media giving the following advantages
    • A low initial Pd over the filter
    • Due to the low Pd there will be little effect on the energy consumption of the fan system
    • There will be a longer lifetime of the HEPA filter due to the large surface area of filter media

The above advantages provide you with a very similar energy cost to run the system.

DATA AND PRODUCT SHEETS FOR H13 HEPA FILTER: click to view in a new tab.

H14 Laminar Flow HEPA Filter Type HLFM14 Data sheet HLFM Laminar Flow HEPA Filters Filtration Categorisation


A growing body of scientific knowledge has raised awareness about the increased health risks for employees and customers which lead to potentially significant liabilities, increased absenteeism and reduced productivity. New buildings and construction are built tight to save energy while older ones are implementing measures to reduce heat and cooling loss. In doing so, the building becomes increasingly air-tight, resulting in not bringing in enough fresh air to dilute workplace contaminants.

Germicidal UVC solution can:

  • Kill 99% of airborne bacteria, viruses and allergens as they pass through the HVAC system and neutralize odours.
  • Prevent the spread of infectious diseases caused by bacteria (including TB, Legionella, E.Coli, and whooping cough) and viruses (including colds, flu, measles, German measles, chicken pox, small pox, and SARS).
  • Prevent airborne pandemic threats such as Covid-19, H1N1, SARs, H5N1 and MERS-CoV from spreading through HVAC systems.

A recent trial was conducted where UVC was fitted into cassettes. After a reasonable period of time post fitment results showed an average decrease of 13% in absence rates. Most HR managers would kill for a 0.5-1% reduction!

Biofilms form when mould and bacteria adhere to surfaces in moist environments by excreting a slimy, glue-like substance. Biofilms can be a thin layer or inches thick, depending on environmental conditions… just like the ones in your Heating Ventilation and Air Conditioning (HVAC).

Dust adheres to biofilm surfaces resulting in costly issues:

  • HVAC units are forced to work harder, shortening the lifespan of your equipment, and increasing your energy costs
  • Indoor Air Quality (IAQ) is reduced as mould, bacteria and other bio contaminants spread, impacting the health and productivity of staff or customers
  • Messy, ineffective cleaning solutions force equipment downtime and the use of hazardous chemicals to remove biofilms

Ultraviolet-C (UVC) light is a powerful tool for arresting the spread of unhealthy contaminants.


UVC-Kit splits cassettes -1122C UVC dos & dont’s UVC for HVAC Systems UVC-Kit – fan coils 1140
UVC Cassette install pics UVC in Splits UVC Train3

Carry out internal ducting survey / sampling. Internal cleaning of ducting can be carried out.

Intake and discharge points should not be situated where they will cause vitiated air to be drawn into a system. In existing systems, it may be necessary to extend the intake or discharge point to a suitable position.

Carry out cross talk attenuator survey / sampling. Cleaning of internal section of cross talk attenuators to be carried out, if they cannot be cleaned consider replacement of worst-case examples.

Extract air systems that handle unfiltered air, should be cleaned as frequently as necessary in order to maintain their operating efficiency.

Public Health England has just recently announced that all businesses should flush out their water systems prior to any staff going back into buildings that have been empty for the last few months.

If tea points and drinking points have remained inactive for a long period of time these become dead-legs and a hot spot for the growth of bacteria and Legionella which needs immediate action.

We highly recommend testing systems and flushing/chlorination to be done if required following test results.

Covid-19 Re-opening Operating Plan (ROP)

COLD WATER TANKS Clean and disinfect cold water tanks
COLD WATER DOWNSERVICES To carry out disinfection of all down services pipe work and outlets
HOT WATER VESSELS To turn up the hot water vessels to 65 for one hour and pull thought hot water to outlets

When this has been achieved reduce the temperature to below 60

WATER SAMPLES Before reopening, test for Legionella, Pseudomonas, TVC, Coliforms, E.coli if any of the water samples results are outside the set parameters. Then disinfection again and resample.

Increase maintenance regimes from 3-4 visits per annum to 5-6 visits per annum.

Change AHU filters more frequently, where applicable change filtration rating.

Carry out annual inspection of the ventilation systems.

Need help returning to your premises?

Get in touch to chat about how we can help you