Application of XK-P suspended AHUs

Suspended AHUs are a special type of air handling units intended for indoor use. They rely on monoblock skeleton frame structure using aluminium profiles. Their small size and low profile are helpful in installation in the ceiling void (including in suspended ceilings and under the floor slab), crawl spaces and other similar locations. Suspended AHUs are an ideal choice wherever a useful floor space is very limited or the planning permission does not allow the installation of typical devices (e.g. in historic buildings).

Relatively small dimensions, a compact design and the possibility of installation in a small space are the main advantages of Ratherm suspended units. An XK-P unit can be installed in almost any position: horizontally and vertically (including wall-mounting). This helps to use the space in a building even better.

Ratherm HVAC devices, in addition to supplying fresh air to the building, are also used for heating, cooling, dehumidifying and filtering the air.

Thermal and sound insulation

For any equipment installed indoors, it is extremely important to reduce noise as much as possible. The quieter the units, the greater the comfort in the facility. All our suspended AHUs have a special compact housing which is properly soundproofed. It keeps noise levels to a minimum and also provides thermal insulation for the unit.

Suspended AHU – heat recovery

One of the most important functions of Ratherm suspended AHUs is the possibility of heat recovery. It makes the device much more energy-efficient. Electricity (or gas) consumption is significantly lower, which translates into lower operating costs of the entire system.

The heat recovery function of Ratherm AHUs has a positive impact on the natural environment.

Plate heat exchangers

Heat recovery is achieved with the use of plate heat exchangers. These are devices made of aluminium plates with high thermal conductivity. When warm “used” air that is being removed from the building passes through a plate heat exchanger and it heats the fresh air taken in from the outside. Its special design prevents air mixing.

Plate heat exchangers used in Ratherm AHUs are protected against freezing.

Bypass function

Depending on the time of year, weather conditions and the needs of AHU users, additional heating of fresh air will not, however, always be desired. When ambient temperature is just right, energy recovery may need to be disabled.

The automatic bypass function diverts the air circulation path to skip the heat exchanger. Air is simply evacuated from the building without passing through the heat exchanger. The function is fully automatic and controlled by AHU's software.

AHU heat recovery efficiency

Nominal air flow rate is a parameter that describes how many cubic metres of air will be processed by the plate heat exchanger in one hour of operation. For Ratherm suspended units this value ranges from 1000 m3 for the XK 010 model up to 2800 m3 for the XK 028 air handling unit.

Heat recovery efficiency for the nominal air flow rate amounts to as much as 75–76%. Heat energy savings for the nominal air flow rate depend on the model and range from 13 kW to 36 kW in the largest devices.

AHU sizes

Depending on the needs and preferences of our customers, we offer suspended AHUs in four variants: XK 010, XK 016, XK 022, XK 028. The air flow rate ranges from 600 m3/h (for the XK 010 unit) to as much as 3000 m3/h (for the XK 028 unit). If you are not sure which unit to choose, please use our AHU Configurator or contact our sales department.

Static pressure in Ratherm suspended AHUs

The main purpose of an AHU is to provide fresh filtered air. Its amount is strictly dependent on the maximum efficiency of the device. External static pressure is a very important parameter that has a direct impact on the final efficiency of an AHU. This value indicates the capability of a particular unit to generate dynamic pressure.

Air flow in the system faces resistance caused by friction and turbulence. To eliminate this air flow resistance, dynamic pressure is necessary. Without the appropriate level of external static pressure, an AHU would not be able to achieve its design efficiency.

Ratherm XK-P suspended AHUs offer a static pressure of 150 Pa to 300-400 Pa (depending on the device). This is the optimal level that guarantees efficient operation in any conditions.

Fans

We use high-quality EC centrifugal fans in our devices. They are highly efficient and offer variable velocity control as well as lower energy consumption. In the case of suspended AHUs, the noise level is even more important than in the case of AHUs installed outdoors. To ensure the maximum comfort, the supply and exhaust fans used in Ratherm units generate low levels of noise.

Air filtering

The issue of air pollution in Poland intensifies with each heating season. Despite various measures being taken, smog is still a very serious threat. Polish air is one of the most polluted in the entire European Union. Air supplied by Ratherm AHUs is filtered through G4, M5, and F7 class filters. Filtering significantly improves the quality of air supplied to the building, with a positive effect on the comfort and health of its occupants.

Learn more

For more information, please contact our sales department. We are happy to work with you anywhere in Poland.
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