Warehouses are hard buildings to keep comfortable. High ceilings, large loading doors and thin roof cladding mean they can be cold in winter and very warm in summer, and an ordinary office-style unit is rarely up to the job.
This guide explains how warehouse air conditioning works, which systems suit large spaces, what to think about before you choose one, and how to keep it running well. It also covers lower-energy options such as HVLS fans and evaporative cooling.
What is warehouse air conditioning?
Warehouse air conditioning is a system designed to control temperature, humidity and air movement across a large, open building. Unlike a single room, a warehouse has warm air building up near the roof, draughts from open doors and areas used in very different ways.
Most modern systems are reverse-cycle heat pumps, so the same equipment cools the building in summer and heats it in winter. That makes air conditioning a year-round climate control system rather than something you only switch on during a heatwave.
Why do warehouses need proper temperature control?
The first reason is your staff. Under the Workplace (Health, Safety and Welfare) Regulations 1992, employers must keep indoor workplaces at a reasonable temperature. HSE guidance suggests a minimum of around 16°C, or 13°C where the work involves a lot of physical effort.
Heat in summer is just as much of a problem. People working in a hot, stuffy building tire more quickly, lose focus and are more likely to make mistakes, which matters around forklifts and heavy stock.
The second reason is your stock. Food, medicines, electronics, paper and textiles can all be damaged by heat or damp. High humidity can also cause condensation on racking, floors and packaging, which creates slip hazards and can lead to mould.
Types of warehouse air conditioning systems
The best system depends on the size of the building, how it is used and where equipment can be placed.
Split systems
A split system has an indoor unit connected by refrigerant pipes to an outdoor unit containing the compressor. For warehouses, the indoor units are usually ceiling-mounted cassettes or high-level wall units. Splits are quick to install and work well for smaller warehouses, mezzanine offices or zones that need extra cooling. Where you need several indoor units from one outdoor unit, a multi-split air conditioning system can save space outside.
Packaged and rooftop units
Packaged units hold all the main parts in one cabinet, and the conditioned air is delivered through ductwork. Many are installed on the roof, which keeps floor space free for racking and vehicles. They are fairly simple to install and suit large, open buildings with one main zone.
VRF and VRV systems
Variable refrigerant flow (VRF) systems, also known as VRV, connect many indoor units to one outdoor system. The flow of refrigerant changes to match the demand in each zone, so a dispatch area, a temperature-sensitive store and a staff office can all be controlled separately. Some VRF systems can heat one area while cooling another, which suits mixed-use warehouses where energy efficiency is a priority.
How to choose the right system for your warehouse
Building size, height and layout
Floor area is only part of the picture. Ceiling height has a big effect, because warm air rises and collects in the roof space, away from the people working below. Tall racking and mezzanines also block airflow, so unit positions need careful planning to avoid hot and cold spots.
Heat gains and how the space is used
An engineer will look at where heat comes from: sunlight through the roof, lighting, machinery, battery charging areas and the number of staff. Loading doors that open all day let a lot of outside air in, which affects the size of system needed. Separate areas such as offices, canteens or a server room may need their own controls.
Running costs and access for servicing
A warehouse system can run for long hours, so efficiency has a real effect on your energy bills. Modern inverter units adjust their output rather than switching fully on and off, and zoned controls mean you only condition the areas in use. It is also worth thinking about access: units fitted high on a ceiling may need a cherry picker for every air conditioning service, which adds cost over the life of the system.
Other ways to cool a large warehouse
These options can work on their own in some buildings, or alongside air conditioning to reduce the load on it.
- HVLS fans (high volume, low speed) are large ceiling fans that move a lot of air slowly. In summer they create a gentle breeze that helps people feel cooler. In winter they push warm air back down from the roof, cutting heating costs.
- Evaporative cooling draws outside air through wet pads, where the water evaporates and lowers the air temperature. It uses far less electricity than refrigerant-based cooling, but it adds moisture to the air, so it is not suitable for goods that are sensitive to humidity.
- Thermal energy storage produces cooling, often as chilled water or ice, when electricity is cheaper and releases it during the day. It tends to suit very large sites with high, predictable cooling loads, usually as part of a chiller system.
How should you maintain warehouse air conditioning?
Warehouses are dusty places, so filters and coils clog faster than in an office. A blocked filter forces the system to work harder, raising energy use and the risk of a breakdown. Most sites need an annual service at the very least, with busy or dusty buildings needing more frequent visits.
A typical service includes cleaning or replacing filters, cleaning indoor and outdoor coils, checking refrigerant pressures and pipework for leaks, testing controls, clearing condensate drains and inspecting fans and electrical connections.
Our REFCOM registered, F-Gas certified engineers have more than 20 years' experience installing and servicing systems for warehouse and industrial sites, working from Westhoughton, Bolton, with teams across the UK. If you would like advice on your building, book a free site survey and quote.
Frequently asked questions
Is there a maximum working temperature for warehouses in the UK?
No. There is no legal maximum working temperature in the UK. Employers must still keep the temperature reasonable and assess the risk where heat could affect staff, which may mean adding cooling, ventilation or extra breaks.
Can warehouse air conditioning heat the building as well?
Yes. Most modern split, packaged and VRF systems work as heat pumps, so they provide heating in winter as well as cooling in summer. That gives you one system to manage all year.
How much does a warehouse air conditioning service cost?
Our annual air conditioning servicing costs £85 plus VAT. Larger warehouse systems with many indoor units or ducted equipment may need more time, so we will confirm the cost once we know what is installed.
Do I need a certified engineer to install or repair warehouse AC?
Yes. Under F-Gas rules, anyone who installs, services or repairs equipment containing refrigerant gases must hold the right F-Gas certification. Using a certified engineer keeps you compliant.
Categories: Uncategorized
