Walk into many shops, banks or reception areas in winter and you’ll pass under a warm stream of air at the door. That’s an air curtain. It lets a business keep its door open to welcome customers without heating the street, and it helps keep summer heat, dust and insects out too.
This guide explains how air curtains work, the difference between electric and heat pump models, the mounting options and how to tell whether one suits your entrance.
How an air curtain works
Mitsubishi Electric’s UK knowledge file describes a warm air curtain as a fan coil that blows air downwards across an open entrance to create a barrier, keeping conditioned air in and contaminants out. The air stream reduces the mixing of warm indoor air with cold outdoor air, so less heat is lost through the opening.
It isn’t a sealed door. Wind, the size of the opening and pressure differences in the building all affect how well it works, so the unit must be matched to the doorway.
Electric and heat pump air curtains
Many air curtains heat the air with electric elements. Heat pump air curtains are connected to an air conditioning or heat pump outdoor unit, so the heat comes from the refrigerant circuit instead, which is usually more efficient than direct electric heating.
- Mitsubishi Electric says it launched the first heat pump air curtain in 2008, in collaboration with Thermoscreen.
- Daikin’s UK range of Biddle air curtains is designed to combine with Daikin air conditioning, and Daikin lists Sky Air and VRV as related products.
Manufacturers publish efficiency and payback claims for their own models; Daikin’s page, for example, says its Biddle units can reduce heat loss through the door by 80 to 85%. Treat these as the manufacturer’s figures and ask for data that matches your doorway and use.
Mounting types
Daikin’s Biddle range shows the three usual formats:
- Wall-hung: a unit mounted on the wall above the door. Simple to fit and easy to service.
- Cassette: mounted in a false ceiling, with only the decorative panel visible.
- Recessed: fully concealed in the ceiling, with only a slim grille.
The choice depends on the ceiling, the look you want and the access for maintenance.
Where air curtains make sense
- Shops and showrooms that keep the door open. See retail air conditioning.
- Receptions and lobbies in offices, hotels and surgeries.
- Restaurants and cafés with busy entrances.
- Warehouses and loading bays, where industrial air curtains reduce heat loss at dock doors. See our warehouse cooling guide.
Want it done properly? AirCon Doctor installs, repairs and services air conditioning and heat pumps across London and the South East, from our base in East Grinstead. We’re an F-Gas certified company and NICEIC approved. Get a fixed-price quote.
Sizing and installation
An air curtain should be at least as wide as the opening, and its power must suit the door height. Daikin, for example, groups Biddle models by door height range. We look at:
- the width and height of the opening;
- how exposed the entrance is to wind;
- whether there’s a lobby or second set of doors;
- how the curtain will connect to the existing air conditioning or a new outdoor unit;
- controls, such as door contacts so the curtain runs harder when the door is open.
Air curtains and the rest of the system
An air curtain works best as part of a joined-up system. Without one, a heating system near the door may struggle and run harder, and staff near the entrance feel cold. With one, the main air conditioning or heat pump can maintain the space more steadily. For a VRF building, a heat pump air curtain can be connected to the same system. Our VRF and commercial air conditioning pages explain more.
Servicing
Air curtains collect dust and debris from the street. Filters and fan coils need regular cleaning, and heat pump models need the same refrigerant and electrical checks as any other indoor unit. Adding the air curtain to your maintenance contract keeps it efficient.
Getting a quote
Air curtains are priced after survey, because the doorway, the ceiling and the connection to the system all vary. Business premises pay the standard rate of VAT. Get in touch and we’ll reply the same working day.
Quick answers
What does an air curtain do?
It blows a stream of air down across an open doorway, reducing the mixing of indoor and outdoor air so less heat escapes in winter and less heat and dust come in during summer.
Is a heat pump air curtain better than an electric one?
Heat pump models take their heat from a refrigerant circuit, which is usually more efficient than direct electric heating. The best choice depends on the site and existing system.
Can an air curtain connect to my existing air conditioning?
Some can, depending on the brand and system. We check compatibility at survey.
Does an air curtain replace a door?
No. It reduces heat loss through an open doorway but doesn’t seal it. Wind and door size affect performance.
Related services
- Retail air conditioning
- Commercial air conditioning
- VRF air conditioning
- Air conditioning maintenance contracts
More advice
- Air Conditioning for Retail: Shop and Showroom Guide
- Warehouse Air Conditioning and Cooling
- What Is VRF Air Conditioning? Guide for Business Owners
- Commercial Air Conditioning: What Businesses Need to Know
- All advice
This guide is general information, checked against the sources linked on 30 October 2026. It isn’t legal, tax or financial advice. Rules, grants and product ranges change, so check the current position before you rely on it.