Temporary air conditioning hire during HVAC maintenance helps keep critical areas operational while permanent systems are serviced, repaired or replaced.
Replacing, upgrading or maintaining a commercial HVAC system creates one important question:
What keeps the building operational while the permanent cooling system is offline?
Temporary air conditioning can provide replacement or additional cooling during:
- Planned HVAC maintenance
- Major repairs
- Equipment replacement
- Chiller repairs
- Plant upgrades
- Refurbishment
- Delayed permanent installation
- Building works
- Staged HVAC replacement
Planning temporary cooling before the shutdown gives you time to assess the required capacity, priority areas, available power, equipment locations, heat rejection, access and installation requirements before the permanent system is taken offline.
Aircon Rentals provides commercial portable air conditioner hire and larger temporary cooling solutions for short and long-term hire during planned maintenance, repairs, upgrades and replacement projects across commercial and industrial facilities.
Why Plan Temporary Cooling Before HVAC Work Starts?
A planned shutdown gives you something an unexpected breakdown does not: time to prepare.
Before permanent HVAC equipment is isolated, confirm:
- Which areas must remain operational
- Required temporary cooling capacity
- Equipment locations
- Available electrical power
- Exhaust, duct and hose routes
- Site access
- Installation timing
- Expected shutdown duration
Where practical, the temporary cooling system can then be installed, commissioned and tested before the permanent HVAC equipment goes offline.
This reduces the risk of discovering access, power, heat-rejection or capacity issues after the shutdown has already started.
Plan, install and test temporary cooling before isolating the permanent HVAC system to reduce shutdown risk and disruption.
Decide Which Areas Actually Need Temporary Cooling
You may not need to replace the entire permanent HVAC load during the works.
Start by identifying the areas that must remain operational, such as:
- Server rooms
- Equipment rooms
- Occupied offices
- Customer-facing areas
- Retail spaces
- Critical production areas
- Control rooms
- Meeting rooms
- Heat-sensitive equipment
If only selected work areas, people or equipment require cooling, see our Spot Cooling vs Whole-Room Cooling Guide before determining the temporary capacity required.
Portable AC for Smaller Areas
Portable air conditioning can suit individual rooms and smaller commercial areas that need to remain operational while permanent HVAC equipment is offline.
Typical applications can include:
- Offices
- Meeting rooms
- Retail spaces
- Server rooms
- Temporary workspaces
- Individual tenancy areas
Aircon Rentals’ Portable Air Conditioner Hire range includes spot coolers, portable reverse-cycle units and water-cooled split systems for commercial and industrial applications.
Where the requirement is limited to selected people, equipment or work zones, see our Spot Cooling vs Whole-Room Cooling Guide for more detail on choosing the right approach.
Real Project: 1,000kW Temporary Cooling During an Occupied Building Refurbishment
A 26-storey Brisbane government building was undergoing a major end-of-life refurbishment while remaining occupied.
The existing central chiller plant was located on the 26th floor and included ageing equipment, with part of the permanent cooling capacity already offline. Aircon Rentals was engaged to provide 1,000kW of temporary cooling capacity while the refurbishment and staged replacement of the permanent plant progressed.
Aircon Rentals supplied:
- 5 × 200kW air-cooled chillers
- Pumps and associated temporary equipment
- A modular installation designed around limited ground-floor space
- Temporary cooling for a 20-week hire period
The temporary chillers were installed at ground level, avoiding the cost and complexity of positioning temporary equipment on the upper floors.
The system supported the occupied building throughout the refurbishment period with minimal disruption.
Read the Building Refurbishment Temporary Cooling Case Study
This project demonstrates why temporary HVAC planning is not simply about matching equipment capacity. Equipment location, access, installation logistics and how the building will operate during the works all need to be considered.
Do Not Automatically Match the Permanent HVAC Capacity
The installed capacity of the permanent HVAC system does not necessarily equal the temporary cooling capacity required during the works.
For example, a building with 200kW of permanent installed capacity may not need 200kW of temporary cooling if:
- Some spaces will be unoccupied
- Sections of the building will be closed
- Production will be reduced
- Only critical areas need cooling
- Work will occur outside normal operating hours
The temporary system should be sized around the actual operating load during the shutdown, not simply the nameplate capacity of the permanent equipment.
If portable equipment is likely to form part of the solution, see our Portable Air Conditioner Hire Cost Guide for the factors that influence equipment hire, installation and total project cost.
Real Project: Temporary Cooling During Planned Chiller Repairs
A major Melbourne hospital needed to repair an existing 1,400kW water-cooled chiller serving the building.
Rather than simply matching the permanent chiller’s nameplate capacity, Aircon Rentals worked with the hospital engineering team to design a temporary system around the site’s actual operating, hydraulic and installation requirements.
The temporary system included:
- 1 × 430kW nominal air-cooled rental chiller
- 1 × 520kW nominal air-cooled rental chiller
- 2 × variable-speed chilled-water pumps
- 120m of temporary chilled-water lines
- 160m of temporary electrical cable
- Temporary switchboards and associated equipment
Because the permanent plant was located in a below-ground plant room, pressure, flow, hose routing, electrical connections and site logistics all had to be considered before the temporary system could be commissioned.
Installation was completed over two days. Once repairs to the permanent 1,400kW chiller were complete, the cooling load was transferred back from the temporary system in stages so the repaired system could be verified before the rental equipment was removed.
Read the Melbourne Hospital Planned Chiller Repairs Case Study
The key lesson is that temporary HVAC capacity should be engineered around the site’s actual operating conditions during the shutdown, not selected solely from the permanent equipment nameplate.
When Are Package Units More Appropriate?
Portable air conditioners are useful for smaller rooms and targeted cooling requirements, but they are not always the most practical option for larger occupied areas.
A reverse cycle package unit may be more appropriate where:
- Larger areas need to remain operational
- Higher airflow is required
- Multiple portable units would otherwise be needed
- Temporary supply and return ductwork can be installed
- A more centralised temporary cooling solution is practical
Aircon Rentals supplies Reverse Cycle Package Unit Hire for commercial and industrial temporary cooling requirements.
Check Power Before the Shutdown
Temporary HVAC equipment can create a significant additional electrical load, especially where larger package units, chillers, pumps or multiple portable units are required. Before installation, confirm:
- Available outlets
- Switchboard capacity
- Three-phase power where required
- Circuit capacity
- Temporary cable routes
- Distribution requirements
- Whether temporary generation is required
The temporary cooling design and temporary power requirement should be assessed together.
Identifying power limitations before the shutdown can prevent delays, equipment changes or unexpected generator requirements once installation begins.
Plan Heat Rejection and Ducting
Temporary air conditioning does not remove heat from a building. It transfers that heat to another location.
Depending on the equipment and site conditions, the temporary installation may require:
- Exhaust ducting
- Supply-air ducting
- Return-air ducting
- Flexible hoses
- External heat-rejection space
- Remote equipment positioning
These routes should be assessed before shutdown day so the temporary equipment can be installed without creating avoidable access, airflow or operational problems.
Where ceiling space may be used for temporary ducting, see our Ceiling Types for Temporary Air Conditioning Installation guide.
If portable equipment is being considered and conventional hot-air exhaust is difficult, see our Air-Cooled vs Water-Cooled Portable Air Conditioner Guide.
Plan Equipment Access
Correctly sized temporary HVAC equipment still needs to physically reach the installation location.
Before delivery, confirm:
- Delivery route
- Loading-area availability
- Door dimensions
- Lift capacity
- Stairs
- Crane requirements
- Equipment positioning
- Public-access restrictions
- Working-hour restrictions
- Site inductions
- Permits
For larger chillers, package units or other temporary plant, access and lifting requirements can influence the equipment selection itself.
Identifying these constraints before the shutdown helps avoid delays or last-minute changes to the temporary cooling design.
Install and Test Before Permanent HVAC Goes Offline
Where practical, the temporary cooling system should be installed, commissioned and tested before the permanent HVAC equipment is isolated.
A typical sequence may be:
Deliver → Position → Connect → Commission → Test → Isolate Permanent HVAC
Testing first allows the site team to confirm:
- The temporary system can maintain the required conditions
- Airflow is reaching the priority areas
- Power supply is sufficient
- Pumps, hoses and ductwork are operating correctly
- Temperature monitoring is working
- Any redundancy requirements are in place
Temporary HVAC should be installed, commissioned and tested before the permanent system is taken offline, where practical.
The hospital server-room project provides a good example. Aircon Rentals completed a four-hour operational test before the hospital began its 18-hour chilled-water shutdown.
Read the Hospital Server Room Temporary Cooling Case Study
Testing before shutdown reduces the risk of discovering a capacity, power or installation issue only after the building has become dependent on the temporary system.
What Happens During the Hire?
For longer temporary HVAC projects, the system may need ongoing monitoring and maintenance while the permanent works continue.
Depending on the application, this can include:
- Temperature monitoring
- Equipment inspection
- Filter cleaning
- Condensate management
- Fuel management where generators are used
- After-hours support
- Monitoring changes in occupancy or operating load
Temporary cooling requirements can change during a project. Occupancy may increase, production loads may change or site conditions may become more demanding.
The restaurant project provides a good example. Aircon Rentals technicians carried out inspections and filter cleaning because the commercial kitchen environment created more demanding operating conditions.
Ongoing monitoring helps ensure the temporary system continues to match the actual conditions throughout the hire period.
What Happens When the Permanent HVAC System Returns?
The return to permanent HVAC should be planned just as carefully as the temporary installation.
A typical handback may involve:
- Confirming the repaired or replacement system is operating correctly
- Transferring the cooling load back to permanent equipment
- Monitoring temperatures and system performance
- Isolating the temporary system
- Disconnecting ducts, hoses and temporary power
- Removing rental equipment
- Reinstating temporary openings or access arrangements where required
For critical sites, the load may be transferred back in stages so the permanent system can be verified before the temporary equipment is fully removed.
Demobilisation should therefore be planned as part of the overall temporary HVAC project, not treated as an afterthought.
Temporary HVAC Planning Checklist
Before permanent HVAC equipment is taken offline, confirm the key planning, operational, power, access, installation and redundancy requirements below.
Use this temporary HVAC planning checklist before taking permanent equipment offline to confirm cooling requirements, power, access, installation and redundancy.
Need Temporary Cooling During HVAC Maintenance or Replacement?
For smaller and targeted applications:
For larger requirements:
Reverse Cycle Package Unit Hire
Request a Temporary Cooling Quote
Call 1800 626 996