Air Curtains

An air curtain — also called an over door heater or air door — is a fan unit fitted above an entrance that blows a controlled stream of air downward across the opening, creating an invisible barrier between inside and outside. It keeps heated internal air in, blocks cold air, insects and airborne dust from entering, and lets the doorway stay open without the usual energy and comfort penalty. We stock commercial air curtains from Frico and Thermoscreens, covering door widths from 0.8m to 2.0m in heated (electric) and ambient (unheated) versions. Suitable for retail shops, restaurants, warehouses, loading bays, public buildings and commercial entrances. Air curtains work particularly well alongside other commercial heaters to improve temperature control across entrances, workspaces, and larger open areas.

Duct Heaters / Radiant Heaters

What does an air curtain do?

An air curtain creates a high-velocity downward airflow across a doorway that acts as a physical barrier between the internal and external environments. The airstream separates the two air masses, significantly reducing the exchange of heat, humidity, insects and airborne contaminants when the door is open. The effect is three-fold: internal temperature is maintained (reducing heating or cooling costs), flying insects and dust are blocked, and the entrance stays welcoming to customers or staff without the discomfort of cold draughts or the cost of heat loss.

Air curtain vs over door heater — what's the difference?

They are the same product. "Air curtain" is the commercial/technical term and is the more common industry name. "Over door heater" is the retail/installer term that describes what the product physically is — a heated fan unit mounted over a door. Both terms describe the same unit, and you'll see them used interchangeably on product listings, datasheets and installer drawings. Our range covers both heated (electric) and ambient (unheated) versions — "over door heater" is usually used specifically for the heated versions.

Do I need a heated or ambient air curtain?

A heated (electric) air curtain warms the airstream as it blows across the doorway, actively adding heat to the entrance area. Best for shop entrances, restaurants, hotels and customer-facing doors in cold climates — anywhere staff and customers feel the door draught and where the building heating system is working hard to keep the entrance warm. An ambient (unheated) air curtain uses an unheated airstream. The barrier effect still works — it's the velocity of the airstream, not the temperature, that separates the two air masses. Best for loading bays, cool storage, industrial entrances and anywhere temperature separation is needed but added heat isn't. Ambient curtains are also cheaper to buy and far cheaper to run, so specify ambient unless there's a clear need for added warmth.

What width air curtain do I need?

As a general rule, the air curtain should be at least as wide as the door opening it covers — a 1m door needs a 1m curtain, a 1.5m door needs a 1.5m curtain. For wider openings, two curtains can be installed side by side to cover the full width. Our Frico PA range covers standard widths from 1.0m (PA2210) through 1.5m (PA2215) to 2.0m (PA2220). Thermoscreens C1000/C1500/C2000 cover 1.0m, 1.5m and 2.0m. For openings wider than 2m or for roller shutter doors up to 5m wide, we can source larger Frico industrial air curtains to order — contact us on 0161 399 3825.

How high above the door should an air curtain be mounted?

Air curtains are designed to be mounted as close to the top of the door as practical — typically directly above the door frame, within 200mm of the door opening. Mounting too high reduces the effectiveness of the air barrier because the downward airstream loses velocity before it reaches the occupied zone. For doors taller than about 2.5m, a higher-velocity industrial air curtain is needed, or two curtains stacked. Mounting above a false ceiling is possible with recessed models — surface-mounted units must have the air outlet directly exposed to the doorway.

Are air curtains energy efficient?

Yes, when correctly specified and installed. A well-specified air curtain can reduce heat loss through an open doorway by 70–80%, paying back its running cost many times over in reduced heating demand. Look for EC (electronically commutated) motor models for the lowest running cost — Frico PA2200 series uses EC motors and variable speed control. Integrating the air curtain with a door switch so it only runs when the door is open reduces energy use further. For entrances with heavy customer traffic, the savings easily justify the investment; for occasional-use doors, an ambient curtain with a door-switch interlock is the most efficient setup.

How are air curtains controlled?

Most of our air curtains include integrated controls with multiple fan speeds and heat settings. The Frico PA2200 range includes remote control and an integrated controller for speed, heat and scheduling. Thermoscreens units include wired controllers with similar functionality. For building management integration, most models offer 0–10V speed control input and thermostat/door-switch interlock inputs — see the individual product datasheets for specific control options. For commercial installations, pairing the air curtain with a door switch ensures it only runs when the door is open, maximising energy efficiency.

Can air curtains be used on loading bay or warehouse doors?

Yes. Ambient air curtains are the standard solution for warehouse and loading bay doors where the goal is temperature separation without the running cost of electric heating. For wider openings (roller shutter doors over 2m wide), use Frico industrial air curtains — sourced to order in larger sizes. For cold storage or food hygiene applications, the air curtain also helps with pest exclusion and airflow separation between temperature zones. Contact us with the door width, height and usage pattern for a sizing recommendation.

Frequently Asked Questions

What is the purpose of air curtains?

Air curtains create an invisible barrier of high-velocity air across doorways or openings, preventing warm or conditioned air from escaping and stopping cold drafts, dust, and insects from entering. They help maintain indoor temperatures, improve energy efficiency, and enhance comfort in commercial spaces.

Do air curtains really work?

Yes, properly sized and installed air curtains are highly effective. They maintain temperature separation between indoors and outdoors, reduce energy loss, and improve indoor air quality by limiting dust and pollution ingress. Efficiency depends on correct installation, height, and airflow speed.

Are air curtains expensive to run?

Air curtains are energy-efficient when correctly specified. Most commercial units use minimal electricity relative to the energy saved by reducing heat loss or maintaining air conditioning. For high-traffic entrances, they can significantly lower energy costs compared to unprotected openings.

Do air curtains work in winter?

Yes. Air curtains prevent warm indoor air from escaping and cold external air from entering, making them particularly effective in winter. They maintain comfort near entrances and help reduce heating costs, especially in high-traffic or open-door environments.

What is the lifespan of an air curtain?

Commercial air curtains typically last 10–15 years with regular use and maintenance. Lifespan depends on usage, environmental conditions, and routine cleaning of filters, motors, and fan components. Choosing a high-quality unit ensures reliability over long-term operation.

Are air curtains worth it?

Yes. Air curtains provide tangible benefits for commercial buildings, including energy savings, improved comfort, hygiene, and reduced drafts. For retail, office, industrial, or hospitality entrances, they are a cost-effective way to protect interior climate and maintain operational efficiency.

How to choose an air curtain?

When selecting an air curtain, consider:

• Door width and height – ensure the airflow covers the full opening.

• Mounting type – ceiling-mounted, recessed, or integrated into existing door frames.

• Airflow velocity and volume – sufficient to create a consistent barrier.

• Heating options – some units include electric or water heating for additional warmth.

• Environment – high-traffic or external-facing entrances may need more robust units.

How to size an air curtain?

Sizing is based on door dimensions, building layout, and usage frequency. Match the unit’s width to the door opening and ensure the airflow velocity is enough to reach the floor without causing excessive turbulence. High or wide doors may require multiple units or high-capacity models to maintain an effective barrier.