General HVAC Overview

HVAC systems are designed to provide a safe working and living environment within various enclosed hazardous and non-hazardous areas of an installation/site or work place. These systems are designed to, but not limited to maintaining the following conditions on any client asset:

  • Provide specific Air Volumes to individual areas (Supply).
  • Remove specific Air Volumes to individual areas (Extract).
  • Allow venting of excess air (Exhaust).
  • Maintain required Air Change Rates.
  • Maintain and control humidity.
  • Provide Positive Pressure with reference to atmosphere to individual modules/areas.
  • Provide Negative pressure with reference to atmosphere to individual modules/areas.
  • Provide Differential Pressure between Hazardous & Non-Hazardous modules/areas.
  • Maintain specific Temperatures in modules, areas for Equipment and/or the Workforce.
  • Provide Cooling in modules/areas for both Equipment/Workforce.
  • Provide Cooling for Fridges/Freezers at a specific Temperature Range for the purpose of food storage.
  • Minimise exposure of personnel/workforce to Substances Hazardous to Health (COSHH) and discharge into a safe area.
  • Maintain Temporary Refuge Integrity (TR) and reduce risk of smoke/gas ingress to ALARP.

To ensure that the original design objectives of the various HVAC Systems are continuously achieved, it is necessary to monitor and carry out routine inspections and performance checks.

If failure occurs, or if it is necessary to undertake maintenance on HVAC systems, appropriate temporary controls and / or equipment should be put in place to mitigate any shortfall in protection caused by the failure or maintenance activity.

Loss of HVAC or Refrigeration systems on any asset and poor maintenance of a TR Boundary and associated equipment may result in a potential down man or evacuation of personnel due to loss of Safety Critical Equipment (SCE) or a Major Accident Hazard (MAH) being realised.

HVAC and Refrigeration Systems are designed to maximise safety of the personnel, equipment and asset itself, so maintenance of these systems is Safety Critical and will maximise productivity and maximise the life cycle while reducing risk in a controlled manner.

HVAC Performance Assurance

In order to maximize the performance of all HVAC Systems on an asset, Dickson’s HVAC Ltd recommend that an inspection of all systems and performance checks are carried out on an annual basis to ensure systems are operating within their design parameters and there are no major issues. This is a preventative maintenance routine that will highlight potential issues and failures, maximizing operations and production, whilst mitigating the risk of system failure and down time.

Our Company provides engineers with years of experience and are trained to a minimum P601 Thorough Examination and testing of LEV systems, giving the client confidence that there is a recognized industry qualification and work with clients on a hands-on basis to resolve issues as they are identified where practicable. Our main objective is to ensure clients have safe and operational HVAC systems and report any potential issues with suitable recommendations, prior to becoming a risk of failure. We want to see clients with reliable systems, and where repairs are required, allow this to be carried out in a safe and controlled manner.

Dickson HVAC Ltd will prepare standardized reports that can be utilized as procedures that are site specific and system specific for a client for the purpose of standardizing all future testing. This can be implemented across all client sites/assets which will reduce long term costs, by reducing time spent on inspection, testing and reporting.

Mandatory Inspection Testing

Temporary Refuge Integrity (TRI) Testing

The primary goal of any Temporary Refuge (TR) is to ensure the safety of the asset personnel during a major fire/explosion or gas release incident while they remain on the asset. The secondary goal of the TR is to provide the necessary facilities to allow the management to implement the Emergency Response Plan, including the organization of evacuation/escape, as necessary. The muster areas, TR & supporting structures are typically designed such that in a design explosion event, personnel are protected from structural collapse, fire, products of combustion, hazardous or toxic clouds for sufficient time to enable safe & orderly evacuation.

Duty holders are required to ensure all foreseeable integrity threats (Major Accident Hazards) are identified and their potential for TR impairment assessed. From this assessment, suitable and sufficient performance standards should be established for the components systems identified as safety critical. A high number of these elements and systems are mechanical HVAC, which require adequate maintenance, inspection and testing to sustain the specified integrity and mitigate the risk of ingress, otherwise, the TR may fail to provide the protection required during a major incident and fail to protect personnel and lead to a significant loss of life.

Duty holders should also demonstrate that the TR has sufficient integrity to ensure impairment is as low as reasonably practicable (ALARP) with guidance figures identified by HSE being:

  • New Build – 0.25 Air Changes per Hour
  • All Other Assets – 0.35 Air Changes per Hour

This value has been established as an indictive Air Change that would allow 60 minutes of survivability on an asset. This is a surrogate for societal risk and therefore includes all events capable of preventing TR functionality within the established time required for its survival.

Dicksons HVAC Ltd provides the most competent engineers to insure the integrity of a temporary refuge is of the highest standard. All of our engineers have decades of experience in TRI Testing and are trained and qualified in the most recent TRI City & Guilds standards for the manual inspection, testing, standardized reporting and work with clients on a hands-on basis to resolve issues as they are identified where practicable. Our main objective is to ensure clients have a safe TR with extensive documentation that is ALARP during a single trip and mitigate the requirement for a return visit and re-test.

Where requested, Dicksons HVAC Ltd will prepare standardized procedures that are site specific for a client for standardizing all future testing. This can be implemented across all client sites / assets and reduce long term costs, by reducing time spent on a client asset. Dicksons HVAC Ltd will also provide a confidential and independent 3rd party review of any TR Integrity reports and findings, should this service be required and provide expert advice and recommendations where necessary.

Further guidance for TR integrity testing can be located on the HSE website:

http://www.hse.gov.uk/offshore/trhvac.pdf

http://www.hse.gov.uk/offshore/ed-temporary-refuge-integrity.pdf

Local Exhaust Ventilation (LEV) Testing

The COSHH regulations aim to ensure the safety of all people who deal with hazardous substances. Employers need to assess the risks associated with the handling and use of hazardous substances and eliminate the risks where possible. To meet the requirements of these regulations, employers are required to ensure that local exhaust ventilation is thoroughly examined and tested by a competent person. The maximum permissible duration between these inspections and the reporting of the findings is no greater than 14 months and all systems should be clearly marked identifying Pass / Fail and capture distance where applicable. All testing should be followed up with a detailed report in line with BOHS requirements that can be utilized for historical review and documentation purposes.

Our Company provides engineers with years of LEV experience and are trained to a minimum P601 – Thorough Examination and Testing of Local Exhaust Ventilation Systems and work with clients on a hands-on basis to resolve issues as they are identified where practicable. Our main objective is to ensure clients have safe and operational LEV systems where practicable during a single trip and mitigate the requirement for a return visit and re-test.

Where requested, Dicksons HVAC Ltd will prepare standardized reports that can be utilized as procedures that are site specific and system specific for a client for standardizing all future testing. This can be implemented across all client sites / assets which will reduce long term costs, by reducing time spent on inspection, testing and reporting. Dicksons HVAC Ltd will also provide a confidential and independent 3rd party review of any Local Exhaust Ventilation (LEV) reports and findings, should this service be required and provide expert advice and recommendations where necessary.

Further guidance for Local Exhaust Ventilation can be located on the HSE website:

http://www.hse.gov.uk/lev/

http://www.hse.gov.uk/pUbns/priced/hsg258.pdf

FGas & ODS Regulations

Many refrigeration, fire protection and air conditioning and heat pump systems contain hydrofluorocarbons (HFCs). HFCs are a type of fluorinated greenhouse gas (F gas). Companies that operate or service and maintain equipment containing FGas must meet these requirements.

Look at the list of F gases regulated by the EU and check if your systems contain FGas’s. HFC 404A and HFC 134a are common in refrigeration systems and to find out if your equipment contains one of these F gases you can:

  • Check your manual or the labels on your equipment.
  • Speak to the company that installed your equipment.

Only C&G2079 qualified Engineers & Technicians can carry out work on equipment containing F gases, including:

  • Installation of new equipment.
  • Testing for leaks at set periods.
  • General maintenance of refrigeration, air conditioning and cooling equipment.
  • Labelling of Equipment in line with 2017 requirements.
  • Maintenance of FGas Registers and FGas Logs.

The thresholds at which leak check intervals are specified are expressed in terms of CO2 equivalent. They take into account both the quantity of F gas in the equipment and the ‘global warming potential’ of the FGas (how much the FGas contributes to global warming). This table sets out the:

  • F gas thresholds, in Tonnes CO2 equivalent, at which leak check intervals are specified.
  • Maximum allowed interval between leaks checks for equipment that meets each threshold.
  • Quantities of commonly used HFCs equal to each threshold.

You can find out global warming potentials of other F gases in the list of F gases regulated by the EU, and use global warming potentials to calculate the CO2 equivalent of an F gas.

Further guidance for FGas: Guidance for Users, Producers and traders can be found at https://www.gov.uk/government/collections/eu-f-gas-regulation-guidance-for-users-producers-and-traders.

Dickson’s HVAC Ltd can supply C&G 2079 Category 1 qualified Engineers and Technicians where required to assist with refrigeration plant maintenance, inspections, fault finding and break-downs. We can also have the engineers check the systems and registers for conformity and to ensure current legislation is being achieved.

In addition, and where requested, Dickson’s HVAC Ltd will provide document templates (Registers & Logs) that can be populated for future reference.