HVAC Plant Room Plumbing — Chilled Water & Glycol SWMS
Safe work method statement for plumbing modifications in HVAC plant rooms including chilled water, condenser water, and glycol loop pipework while maintaining building cooling continuity.
SWMS variants reference your state’s WHS legislation. Instant download after payment.
HVAC plant room plumbing covers the plumbing work in heating, ventilation and air conditioning (HVAC) plant rooms — installing, maintaining and connecting the chilled water, heating hot water, condenser water, condensate and make-up water systems that serve the HVAC plant. It combines the plumbing of the water systems with the plant-room environment: the pressurised water systems and their stored energy, the heating hot water and steam, the chemicals used in closed-loop water treatment, the proximity to electrical and mechanical plant, and the potential for confined-space work. This document is written on the basis that HVAC plant room plumbing is carried out by a licensed plumber with the pressure, hot-water, chemical, electrical-proximity and plant-room controls in place.
HVAC plant room plumbing is carried out in connection with the relevant parts of AS/NZS 3500 for the water systems, with the closed-loop water-treatment chemicals managed as hazardous chemicals and the make-up water connection to the drinking water supply protected by backflow prevention. The plant room contains pressurised water systems, heating hot water and steam, electrical and mechanical plant, and condenser-water systems with their Legionella considerations. This document coordinates the pressure, hot-water, chemical, electrical-proximity, Legionella and plant-room controls so the HVAC plant room plumbing is carried out safely.
Hazards identified
9 hazards covered, sorted by priority.
Pressure release and injury from the pressurised water systems
Scalding and burns from heating hot water and steam
Skin, eye and respiratory exposure to the water-treatment chemicals
Contamination of the drinking water from the make-up water connection
Legionnaires' disease risk from condenser and cooling water
Electrical and mechanical plant hazards in the plant room
Atmospheric and restricted-access hazards in enclosed plant spaces
Crush and musculoskeletal injury from the plant and equipment
Burns and entanglement from hot surfaces and rotating plant
Control measures
Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.
- 1Engineering: manage the stored pressure and energy of the pressurised water systems, isolating and depressurising the relevant system before the work.
- 2Engineering: manage the heating hot water and steam, isolating and allowing systems to cool, and controlling the scalding and burn hazard.
- 3Administrative: manage the closed-loop water-treatment chemicals as hazardous chemicals to their safety data sheets, with skin, eye and respiratory protection and handling controls.
- 4Engineering: provide and confirm backflow protection on the make-up water connection to the drinking water supply, so the closed-loop systems cannot contaminate the drinking water.
- 5Administrative: manage Legionella in the condenser and cooling water systems, recognising the Legionella risk of cooling water, and follow the cooling-water management requirements.
- 6Administrative: recognise the proximity to electrical and mechanical plant, with electrical work by a licensed electrician and isolation of plant, and apply confined space controls in enclosed plant spaces.
- 7Engineering: use mechanical aids for pipework, pumps and equipment, and manage hot surfaces and rotating plant.
- 8Administrative: ensure the work is carried out and certified by an appropriately licensed plumber or gasfitter under the relevant state or territory plumbing and gasfitting licensing scheme, with the relevant competencies and a compliance certificate issued where required.
- 9Administrative: all workers must hold a valid White Card (General Construction Induction Training, CPCCWHS1001) where the work is construction work, with the plumbing, gasfitting, confined space and any other competencies required for the work.
- 10Administrative: conduct a pre-start toolbox talk covering the day's work, identified hazards, isolations, required PPE and emergency procedures, and record attendance in the consultation section.
- 11Administrative: consult workers and any health and safety representatives on the work and its risks, record the consultation, and keep this document available at the workplace.
- 12PPE: eye protection to AS/NZS 1337.1, hearing protection where required, gloves appropriate to the task, high-visibility clothing, and Class I or Class II safety footwear with protective toecap to AS/NZS 2210.3.
- 13Administrative: review and update this SWMS whenever the work scope changes, after any incident or near miss, when a worker or health and safety representative raises a concern, when new hazards are identified, or at minimum every 12 months.
Applicable Codes of Practice
The plumbing and drainage standards for the HVAC plant water systems.
The water services standard for the water supply, backflow protection and connection.
Management of the chemicals used in the work, including safety data sheets and exposure controls.
Electrical safety and isolation for any electrical work, carried out by a licensed electrician.
The risk management process and hierarchy of controls applied to the hazards of the work.
Who this is for
- →Licensed plumbers working in HVAC plant rooms.
- →Plumbing and mechanical services contractors on HVAC water systems.
- →Mechanical services and building services businesses.
- →Building owners and PCBUs responsible for HVAC plant.
- →PCBU safety managers and supervisors coordinating the pressure, hot-water, chemical and Legionella controls.
What you receive
- ✓Editable Microsoft Word document (.docx) fully compatible with Microsoft Word 2016 and newer, Google Docs, and LibreOffice Writer.
- ✓Title page with editable fields for PCBU name, ABN, site address, project name, principal contractor details, and document revision date.
- ✓Hazard register with the hvac plant room plumbing hazards — each with a documented consequence, inherent risk rating on a 5x5 likelihood-consequence matrix, hierarchy-of-control measures, and residual risk rating.
- ✓HVAC plant room plumbing prompts referencing AS/NZS 3500, a pressure and hot-water section, a water-treatment-chemical and make-up-backflow section, and a condenser-water Legionella and plant-proximity record.
- ✓Licensing, competency and permit prompts for the relevant plumbing, gasfitting, confined space and specialist work, and a respiratory protection selection and fit-test record per AS/NZS 1715 where relevant.
- ✓Worker consultation record per the model WHS Act consultation duty and a worker sign-on register (blank, expandable).
- ✓Applicable legislation and Codes of Practice schedule pre-populated for the model WHS jurisdiction with a state-variance reference table covering the harmonised states, plus Victoria.
- ✓Emergency procedure template and a revision log.
Worked example
A licensed plumber is engaged to carry out plumbing work in an HVAC plant room. The stored pressure and energy of the pressurised water systems are managed, isolating and depressurising the relevant system before the work. The heating hot water and steam are managed, isolating and allowing systems to cool, and controlling the scalding and burn hazard. The closed-loop water-treatment chemicals are managed as hazardous chemicals to their safety data sheets, with skin, eye and respiratory protection. Backflow protection on the make-up water connection to the drinking water supply is provided and confirmed, so the closed-loop systems cannot contaminate the drinking water. Legionella in the condenser and cooling water systems is managed, recognising the Legionella risk of cooling water, following the cooling-water management requirements. The proximity to electrical and mechanical plant is recognised, with electrical work by a licensed electrician and plant isolated, and confined space controls applied in enclosed plant spaces. Mechanical aids are used for the plant, and hot surfaces and rotating plant managed. The work is completed safely, and the records retained.
Related legislation
- Model Work Health and Safety Act — primary duty of care; the duty to consult workers; the reckless-conduct offence; and notifiable-incident provisions, as enacted in each jurisdiction.
- Model Work Health and Safety Regulations — Section 291 high risk construction work and the SWMS preparation and review duties, and the confined space, excavation and electrical provisions where applicable, as enacted in each jurisdiction.
- The relevant plumbing and drainage standards AS/NZS 3500 (Parts 0–5), AS/NZS 5601.1:2022 for gas, the AS 4032 valve standards, and the hazardous chemicals and electrical requirements, are called up by the state and territory plumbing, gas and safety legislation, together with the relevant network utility, healthcare and site requirements.
- Plumbing and gasfitting work is licensed under each state and territory's plumbing and gasfitting licensing scheme, with the relevant competencies for the specialist work, and compliance certification required for notifiable work; electrical work is carried out by a licensed electrician.
- Victoria operates under the Occupational Health and Safety Act 2004 and the Occupational Health and Safety Regulations 2017, with the high risk construction work, confined space and electrical provisions applying in place of the model instruments.
Frequently asked questions
What does HVAC plant room plumbing involve?
HVAC plant room plumbing is the plumbing of the water systems that serve heating, ventilation and air conditioning plant — the chilled water, heating hot water, condenser water, condensate and make-up water systems. It combines the plumbing with the plant-room environment of pressurised systems, hot water and steam, water-treatment chemicals, and electrical and mechanical plant.
How is the make-up water connection protected?
Backflow protection is provided and confirmed on the make-up water connection to the drinking water supply, so the closed-loop HVAC systems — which contain treatment chemicals — cannot contaminate the drinking water. The make-up water backflow protection is critical because the closed-loop systems present a hazard to the drinking water supply.
What is the Legionella risk in HVAC plant?
Condenser and cooling water systems, such as cooling towers, present a Legionella risk, so Legionella is managed in those systems following the cooling-water management requirements. The condenser-water Legionella management is an important consideration in HVAC plant room work because cooling water can harbour Legionella.
What pressure and hot-water hazards apply?
The HVAC water systems are pressurised with stored energy, and the heating systems contain hot water and steam that can scald. The stored pressure is managed by isolating and depressurising before the work, and the hot water and steam managed by isolating and allowing systems to cool, controlling the pressure and scalding hazards.
Who carries out HVAC plant room plumbing?
HVAC plant room plumbing is licensed plumbing work carried out by a licensed plumber in connection with the relevant parts of AS/NZS 3500, with the pressure, hot-water, chemical, make-up-backflow, Legionella and plant-proximity controls, and electrical work by a licensed electrician. The plumbing is carried out with the controls of the plant-room environment.