Radiant Cassettes Installed in a Semi-Permanent School Assembly Hall

Radiant cassettes provide radiant comfort heat with
zero light or noise output making them ideal for an assembly hall room

The Project

In this case study we look at a space heating project we designed for a semi-permanent assembly hall at a private school in London. Since the pandemic and the introduction of social distancing, semi-permanent structures have become very popular especially in education and health sectors. As a result, demand for heating these types of buildings has increased considerably.

This project was one of the larger temporary structures we have come across and the heating system was expertly installed by Robert Blezard Electrical Contractors.

The Application

As this structure is being used as an assembly hall the heating system we specified needs to be discreet and cannot distract students during assemblies, lectures, audio and visual presentations or exams. (This ruled out the use of fan heating and destratification units which we would tend to specify for an area this size.)

Also, due to the nature of the structure, we were not allowed to wall mount any heaters as the side framework was not suitable. This meant that the heating design was based around ceiling suspended heaters mounted to the overhead support beams.

The team at Robert Blezard Electrical did an
excellent job on the install

Design and Specification

Total Power and Heat Spread – our designers had to ensure we had enough power available to heat the required area and that we could mount the heaters in the correct positions to achieve an even heat spread and so eliminate potential cold spots.

Control – Control is critical. When there is such a large kW load, we must design a scheme which keeps running costs to a minimum. Also, from an installers point of view, we needed to design a scheme that is practical and easy to install. Our specification is below: 

24 x 3.6kW Radiant cassettes (ESP2-36)

2 x 1.2kW Radiant cassettes (ESP2-12)

5 x Control boxes (PC5)

1 x 7-day programmable thermostat (PC-C1)

The Heaters

We specified our longwave radiant cassettes, suspended from support beams as per the drawing above. Longwave radiant cassettes provide comfort heat with no noise, light or draught output. These features make the units ideal for this application as they can be mounted high out of the way and will not distract the students. The added advantage of suspending heaters is that they free up wall and floor space.

Another huge advantage of longwave radiant cassettes is their economy. The cassettes’ gentle radiant effect means an ‘experienced temperature’ can be up to 4°C warmer than the actual air temperature. This means a thermostat can be set up to 4°C lower which equates to a huge saving across a winter.

The Controls

For multi cassettes installs, we always specify our PC control boxes and PC-C1 programmable thermostat. Our PC control boxes can be daisy chained together allowing multiple heaters to be switched via one digital 7 day thermostat.

For an installer, the PC control box simplifies large installations saving time, parts and more importantly installation costs. A typical PC control box installation will require less cable, less MCB’s or RCB’s and less junction boxes. It is also quicker to install as each circuit is individually fused. The 7-day wall thermostat (PC-C1) connects to the control box via Cat-5 cable and does not require mains power.  (Which means you’re not chasing mains cable through the wall)

The Final Project

The team at Robert Blezard Electrical did an excellent job on the install and commissioning of the heaters.

Taking on a similar project? Contact the team at BN Thermic and take advantage of our free design service on 01293 547 361.

This project was well designed and expertly installed