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Recessed Air Curtains – Over Door Heaters – Ambient or Heated

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Recessed air curtain range from Flexiheat UK available in ambient air, hot water fed or electric powered with a maximum mounting height of 5 metres

We do a full range of recessed air curtains / recessed over door heaters, that can either be ambient or non-heated, or heated versions that can either be electrically powered or fed by hot water via a central heating wet system. These heated versions are commonly known as recessed air curtain heaters. With the range being the most popular option in commercial use and are the perfect solution for reception areas, banks, airports ,shopping centres or individual shops ,ensuring the internal temperature of the building and the comfort of the staff and customers, as well as reducing the heat loss through “open-door” trading for commercial premises, via a powerful air stream with a recessed or invisible installation.

A doorway that is left open can allow cold gusts to enter and force heated air to the outside environment, an invisible air curtain is the perfect solution to prevent these heat losses to the outside. They also keep air conditioned air within the reception areas or building in summer time, as they have a fan only setting for air circulation on the heated versions for this purpose.

A diagram showing the working principle of an air curtain by Flexiheat UK

These ceiling mounted air curtains, above ceiling air curtain or in ceiling air curtains if you want to call them that can be mounted together to create longer runs to cover larger doorways or large entrances, with an invisible installation within a suspended ceiling.

These type of air curtains are often the preferred product choice for many retail or commercial premises for all sizes and types of entrances, being not only robust and reliable they also offer high efficiency air separation for almost every doorway, which limits energy losses through an open door with an recessed or invisible installation.

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Recessed Air Curtain Heaters – Maximum Install Height – 5 Metres

What are concealed air curtains and how do they work?

Each entrance that a building has is subject to the laws of physics, that result in the exchange of air via openings or entrances, such as doors etc. When these doors are opened, there is an natural exchange of air , as when a heated air mass and cold air mass interact with each other, for example when the door is opened, the significant density between the two air masses results in the cold air being drawn in at the bottom and the warm air being pulled out at the top. Air curtains , which sometimes are referred to as air doors, help prevent this natural phenomenon, retaining or keeping the two air groups of cold and warm air separate, even when doors are opened – This results in the elimination of draughts and also saves on energy costs, as well as comfort values. When installed in false ceilings ,suspended ceilings or bulkheads above the door way , then often these devices are referred to as concealed or an invisible air curtain to prevent cold draughts and heat loss. A space’s general heating is not the air curtain’s primary function.

Ceiling recessed or invisible installation

So, what is a ceiling air curtain? – well put quite simply, they are devices which are made specifically for recessed or invisible installation into false ceilings, bulkheads above the entrance or a lateral column. They are available in two main types – ambient or non-heated , which just pushes the surrounding air through the air intake and then downwards for air curtain to form the air barrier or seal – or you can have the heated type , which either powered by electric or warm water ,which heats up the air being pushed through the device to give you a heated aerated barrier. As the most popular ceiling tiles in the UK are 600mm x 600mm and 600mm x 1,200mm, all of our models are 600mm wide making them an easy to install in new or existing false ceilings without cutting additional holes or messing about.

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Air Stream and Noise Levels data

Heated or non heated recessed type air curtain ?

Although a heated air curtain will emit heated air, the primary function of the device is not to provide general heating of a buildings space or area. The air curtain will however, when in operation, and the doors are closed, will certainly contribute to heating the surround area of the entrance and associated area. They also help to create a safer area, as the warmth will help melt any sleet or snow or dry any water that has been dragged into the entrance by the throughput of the entrance, via people’s footwear etc.

The heated air curtains options include either-

1.Warm / Hot Water fed air curtains- Low temperature hot water (lthw) with a maximum water temperature of 95 Degrees C, and a maximum water pressure of 16 Bar. The water fed devices are available with either a single or two row heat exchanger should your require more heat output.

2.Electric powered air curtains – these recessed electric air curtains use PTC electrical heating elements. These electric heaters are the latest technology in electric elements or coils as they significantly lower the coil temperature in comparison to older type of electric elements such as wires or spirals. The other advantages are –

  • The complete elimination of the risk of system overheating due to self-regulating modules (the heat capacity automatically reduces when air flow goes down)
  • Lack of voltage on the surface of the electric coil
  • Fully automatic heat control depending on air flow
  • Lower electrical energy consumption
  • Large heat exchange surface i.e. surfaces of contact of the heat exchanger

Suspended Ceiling Applications

These discreet air curtains, sit neatly into suspended ceiling systems, a bulkhead or column and benefit from separated intake and outlets. This feature not only maintains a strong air barrier seal across the opening, but also increases the efficiency.

Air Curtain Recessed – Specification

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Recessed Air Curtain Heater or Ambient Air Curtain – showing the air intake and exit – mounted in suspended ceilings – with the heated air preventing heat losses to the outside environment. The perfect solution for reception areas to prevent cold draughts

This range of recessed appliances are available in three lengths: 1 Metre, 1.5 Metre and 2 Metres and in and three versions: ambient (without heating elements), with a hot water heat exchanger, or with electric heaters. All of our models come as standard with a 3-speed fan and brackets for mounting into the ceiling or void. The hinged grilles ensure access from the front of the unit ensuring easier installation, connection and maintenance or cleaning of the apparatus.

They are designed for indoor use where maximum dust content does not exceed 0.3g/m3 and a maximum mounting height of 5 metres.

Construction – They are made from multiple materials such as aluminium, steel and plastic. These materials used enable a significant reduction in the weight, whilst retaining strength as well lowering the noise level.

As standard they produced in a white colour (RAL 9016) which is an unobtrusive and aesthetically pleasing finish, although they can also be manufactured in other RAL colours at request. Both the inlet grille and outlets vents are manufactured from anodized aluminium profiles, which give these appliances a modern look.

The outlet blades/ lamellas are adjustable within a +/- 10 ° range. By manually setting the angle of the airflow stream, you can adjust the air barrier to suite the site conditions.

Air Curtain Performance

The part number make up for these devices is as follows-

The recessed range is called the “Elis B” – the next figure in the part number donates the following –

W = Water Fed , normally low temperature hot water , these units  are available in either a one row heat exchanger – this being the standard version , or a two row heat exchanger – designated the 2R, placed after the unit length

N = Neutral or non- heated , commonly referred to as ambient air curtains – these require a single phase electric supply

E= Electric powered units – please note all of this range require a 3 phase / 400 volt electric supply

The 3 digits refer to the length

100 =  1 Metre long

150 = 1.5 Metre long

200 = 2 Metre long

Please note that all of our models are 600mm wide, and will fit into the standard 600mm wide ceiling tiles , that are the most popular tile used on the UK market making an invisible installation as such.

Also, these devices can be mounted together to create longer air curtains, and cover all of your site requirements

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Range = maximum mounting height

Unlike many manufacturers or suppliers that make certain performance claims, our door and gate air curtain tests are carried out based on ISO standards, which defines the aerodynamic properties of the appliances to ISO 27327-1 standards and laboratory methods for testing the sound power level to ISO 27327-2 standard.

We take the requirements of the future ISO 27327-3 standard into account, specifying the testing methods to determine the effectiveness of the appliances.

Download the Flexiheat Brochure for Recessed Air Curtain range – Type Elis B

Download the Flexiheat Manual for Elis B Recessed Air Curtain Range

Control Options

There are various options to control these units, ranging from the simplest being a door switch, which activates the unit, on opening of the door, to a fully automatic intelligent regulation system, that has speed regulation of the energy-efficient fans installed and heat settings.

Door switches – We have two options –

  1. Our “DCE”, which is a magnetic remote switch with relay
  2. Our “DCM”, which is a mechanical remote switch switch

These two switches are shown below –

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Manual and Automatic air curtain controllers 

We have two options for controlling this range of air curtains –

Firstly the “TS regulator” – This is the basic and cheapest air curtain controller, for these in ceiling air curtains and it enables the following;

  • Operation of air curtains dependant on temperature i.e. in thermostatic mode, or constant operation of fans, i.e. in a continuous mode
  • Gradation of fan speed (3 steps of fan speed)
  • Selection of heating mode for winter period or ventilation mode for summer period (heating side is switched off)

Up to 5 appliances can be controlled one TS controller

Secondly the “T-Box” controller – BMS Version – This controller is really a control system , which enables control cable connection of the air curtains to the intelligent building management system (BMS) or a  selection of extensive operating modes, and has a weekly programmer , with 2 operating modes:

  1. Configuration 1 – operation when the overriding signal comes from the door sensor as well as from the T-box controller.
  2. Configuration 2 – operation when the overriding signal comes from the door sensor, while the T-box controller is responsible for fan speed regulation and heat settings.

The “T-Box” controller can control up to 31 air curtains

We also can supply 2 port or 3 port control valves for the lthw/ lphw heated ceiling air curtains, these are designated the SRQ valves.

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Recessed Air Curtain Heaters for Sale

These recessed air curtains are designed to offer an economic with high energy efficiency concealed air curtain solution for commercial and industrial premises. Whether you refer to them as recessed, in ceiling, concealed, above ceiling, recessed door, ceiling or a recessed air curtain heater they are all the same, for a recessed or invisible installation for small or large entrances – just different terminologies. Should you require any more air curtain advice or further information please don’t hesitate to contact our sales team on 01202 822221 or click here for our email contact form.