How to take Decoupling further

We congratulate the National Art Gallery of Australia and their consultants, Steensen Varming, for decoupling the processes of adding heat and moisture so that the humidifying process is independent to the heating process (BSj 08/05). The resultant energy saving (41% for gas and 11% for electricity) is outstanding and they should be congratulated. The data for their consumption throughout 2001–2003 would have been interesting.

At the West Wing of the Art Gallery of South Australia (AGSA), we decoupled the process of cooling and dehumidification as a retrofit (the process of heating and humidifying was already decoupled). The result was reduced gas use by over 70% for heating and almost 60% for cooling, with dramatically improved control of the cooling and de-humidifying cycles or process.

The gas consumption for Australia’s National Gallery still shows a comparatively high gas consumption for the cooling months, which indicates that decoupling of dehumidification and cooling has not occurred. Should this be carried out as a retrofit, the gas consumption for the cooling months can be reduced to zero (ie no reheat), together with an accompanying reduction in cooling and hence electrical energy.

The decoupling work at AGSA, together with other energy initiatives, has resulted in reduced electrical usage of over 40% and gas reduction of over 75% for the West Wing. At Siam Cement in Bangkok, one of only two other installations using this process in the world, it has resulted in a 25% reduction in total air conditioning energy with an outside air increase of 900%.