Recent events have brought refrigeration drainage issues into the spotlight, highlighting the need for proper maintenance, compliance with health and safety standards, and liability. This article explores the compliance standards and legislation governing HVACR drainage in food retail.
Compliance Standards and Regulations
Compliance standards ensure the health and safety, welfare, and convenience of a building’s occupants while conserving energy.
The Workplace (Health, Safety and Welfare) Regulations 1992 Reg 12, The Health and Safety at Work etc Act 1974 (HSW Act), The Management of Health and Safety at Work Regulations 1999 are the main legislation used in the event of a Health and Safety prosecution.
Approved Document H of the Building Regulations covers drainage and specifies that the drainage should minimize the risk of blockage or leakage, be accessible for clearing blockages, and prevent foul air from the drains entering the building.
The British Standards Institute -BSEN 12056 prescribes the standards for all indoor gravity drainage.
HVACR Drainage Methods in Food Retail
Three methods are commonly used to move chiller condensate wastewater in food retail: Vacuum, Pumped, and Gravity. Gravity is the most popular.
Vacuum Drainage System: Uses differential air pressure to move wastewater and is to some extent dependent on gravity. They are often laid flat to the sales floor beneath the chiller.
Pumped System: Uses condensate pumps to force the grey water from the sump collection point to the store’s main foul drain. These drains are often laid flat to the sales floor beneath the chiller and are also dependent on gravity.
Gravity System: Depends on a slope from the source to their destination for their effect. The gradient for any indoor sanitary gravity drainage should be between 1.8% and 9%, and drains depend on that flow to keep themselves clean.
Commissioning and Maintenance of HVACR Drains
Proper commissioning and maintenance of HVACR drains are critical to ensure compliance with industry standards and prevent blockages.
Commissioning: Water seals of sanitary appliances should be fully charged and tested. Air pressure equal to 38 mm water gauge should remain constant for a period of not less than three minutes.
Maintenance: Access points should be provided to give access to any lengths of discharge pipe that cannot be reached by removing traps. Pipework should have a minimum 1.8% slope, and all connections should be sealed.
Biofilm and PPM
Non-compliant HVACR drainage can lead to the growth of biofilm and PPM, which are hazardous to human health.
Biofilm: The standard of drainage is a factor in the growth of biofilm EPS (jelly) in condensate drains. Drains with no slope allow the static ‘dead spots’ that suit microbial growth. Ensuring that the drain has a minimum slope is not a guarantee that there will be no biofilm problem – but it will certainly reduce the possibility.
PPM: Proper maintenance of HVACR drains is critical to prevent particulate matter accumulation, which accelerates drain blockages causing water leaks.
Conclusion: Proper maintenance and compliance with industry standards are essential to prevent health hazards, reduce liability, and ensure the safety of building occupants. The lack of industry guidance covering the drainage aspects of a chiller installation in food retail is surprising and underscores the need for increased awareness and attention to this critical issue.