Mitsubishi Electric launches range of packaged AHUs
Mitsubishi Electric now offers in the UK a range of packaged energy-recovery air-handling units with throughputs from 3500 to 15 000 m3/h. There are five models in the Lossnay Kanzen range with COPs from 4.88 to 5.69 and EERs from 5.45 to 6.15. Those five standard sizes enable the company to target just over 40% of the office sector.
The key to the efficiency of these units is Mitsubishi’s Lossnay cross-flow paper core, which can recover both sensible and latent heat.
Heating and cooling is provided using Mr Slim heat-pump outdoor units using R410A.
Mitsubishi has focused on the six other key areas in an AHU to maximise the performance of every element.
The preheating system at the air intake is activated at an external temperature from 0 to -5°C to raise the temperature at the inlet of the heat-recovery core to about 0°C before its temperature is further raised by heat exchange with exhaust air. The direct-acting electric heating elements are thyristor controlled for precise heat output.
A bypass damper can use cool outdoor air to lower the internal temperature and also provide free cooling and night purge with a bypass shutter.
The direct-expansion coil has copper tubing with Blu-fin V Waffle louvre fins in corrosion-resistant aluminium.
Air is moved by fans that are mated directly to EC motors, the speed of which can be set at commissioning stage — after which speed is constant.
There are high-efficiency F7 activated-carbon bag filters upstream of the DX coil and G4 filters in the fresh-air and exhaust-air streams to protect the Lossnay cores.
Integrated controls use M2M technology which can also serve up to 49 Mitsubishi fan-coil units. BEMS control is also available to allow for inputs and outputs to a third-party BMS, fully integrated Modbus BMS and alarm integration.
Installation in confined plantrooms is simplified by being able to break a unit down into six sections — a feature that was used to full advantage when Mitsubishi Electric replaced plant in its rooftop plantroom with two Lossnay Kanzen units. Two gas-fired boilers and a chiller were replaced by four Mr Slim outdoor units.