Watch your movie and breathe easy29 May 2015
There’s nothing like the smell of buttered popcorn at the cinema, but even popcorn can start to grate on your nerves when the person in front of you is loudly tucking into a jumbo tub of it. This, however, is not the biggest problem with going to the cinema these days; it’s the lack of fresh, breathable air in the movie theatre.
Efficient ventilation and air quality has been an ongoing issue for cinema owners and HVAC professionals for some time now. High outside air loads, stringent acoustic requirements, close temperature control and rapid occupancy changes often force designers to move away from conventional packaged systems, meaning the air we breathe when we’re mid-movie is not always the freshest.
Limelight cinema at Riverlink Shopping Centre in Ipswich, Queensland, has created a customised solution to overcome the pungent popcorn aromas – among other things. Using design, engineering and the latest technology, Limelight has devised a special heat recovery system that can maintain comfort and efficiency during the cinema’s peak and low occupancy periods.
Together with high efficiency proprietary heat exchangers, a three-stage 30-70-100 per cent compressor arrangement has been used to provide close temperature control and dehumidification under all conditions. Meanwhile, high indoor air quality is maintained by monitoring CO2 levels in cinemas and running higher levels of outdoor air during peak occupancy.
Limelight’s six on-site cinemas vary between 100-330 seats, meaning a variety of units is needed to cope with differing heat loads. The exchanger units have the capacity to run up to 80 per cent outside air in ‘energy recovery’ mode, with 100 per cent outside air during ‘economy cycle’ on larger units. This means the cinema can vary the flow of fresh air and also provide high levels of oxygen within a space.
With systems selected and air quality requirements met, the acoustic engineer and acoustic consultant also adapted the system to operate extra quietly, so it now generates sound levels within the nominated noise criterion of NR 25 – that’s 10-15 dB(A) quieter than the typical office! Between oxygenation, fresh air supply and whisper-quiet noise levels, this custom HVAC system has well and truly earned its moment in the limelight.