Centre spur plant room – 3rd floor

Ventilation plant for the Print Floor and Business Centre. There was a plant room on both sides of the corridor along the central spur. The north side serviced the Print Floor and the south side serviced the Business Centre.

The plant rooms both have a vastly different layout, as the south plant was totally replaced when the Business Centre was opened. Air is taken in here, filtered, humidified and either heated or cooled, depending on the ambient temperature. It was then passed down to the Centre spur plant room – 2nd floor where it was ducted to the work areas.

The north side had five air handling units (AHUs). AHUs are normally packaged, self-contained items, however, these ones were so large that they are actually part of the building itself. Air was filtered using both pleated and bag filters, which were replaced every six months. Humidity was added using spinning disc humidifiers. 10% of the air was from outside and the rest is recirculated. Recirculating air reduces the use of energy but fresh air needs to be added, particularly in industrial areas such as the Print Floor. It is vital to keep the air conditioned, as the printing process is sensitive to this. The AHU had both a heating battery and a cooling battery; which one is used depends on the ambient temperature.

Four of the AHUs serviced the Print Floor (each one serving two of the eight roof shells) and the other one serviced the areas at the front of the Print Floor (C064). What this was used for after those areas were converted into offices is unknown.

The south side originally had five AHUs, similiar to the north side. Again, four of the five AHUs served the eight roof shells and the other one the front repro areas. The south plant had some significant differences though; the climate in the Helio area was not as sensitive as the Print Floor so it only provided ventilation and (I think) heating and humidification. It was referred to at the time as a ventilation plant while the Print Floor side was referred to as an air conditioning plant.

The vast majority of the south plant was removed in the late 1990s and so were some of the walls of the built-in AHUs. New AHUs were installed here to serve the Business Centre but these were much smaller ‘packaged’ units. They provided heating, cooling, ventilation and humidity, the latter by using steam humidifiers.

NOTE: Photos taken with kind permission by fs³, thanks to Neil who gave me a very informative tour of the building.

Print Floor side

Last updated on Monday 27 February 2023 by GaryReggae