Air-conditioning solutions provider Airco MD Greg Ball says the innovative use of air-conditioning systems, such as heat exchangers and thermal storage units, will provide significant cost savings for Southern African private hospital group Mediclinic’s Morningside Hospital, in Sandton.
Airco has completed 50% of the Morningside retrofit heat and cooling project and expects to complete full commissioning of the heat exchangers and ice bank chillers by the end of this month.
He highlights that the hospital will achieve significant return on investment in about three years.
“The Airco heat exchanger system recovers waste heat produced by the hospital’s chilled water cooler system, after which it produces heat of over
50 °C, which will be used to provide hot water for the hospital,” Ball explains.
He notes that the hospital’s water tanks contain about 54 000 ℓ and, prior to the installation of the heat exchanger system, it used a dedicated heat pump system and heater banks to heat water.
“The heat exchanger system extracts the excess heat from the hospital’s air- conditioning system, which operates 24/7 . . . to also cool the water,” Ball points out.
Further, he says the Calmac thermal storage system will ensure that the hospital’s chillers do not run during peak loads.
Ball states that there are peaks caused by increased power use – usually between 15:00 and 17:00 – which is when the system uses the ice bank system.
“The ice bank system is a simple technology based on storing cooling capacity at night and using it the following day to cool the facility,” he explains.
Ball says that, at night, when electricity is generated at a lower cost, chillers cool fluid and store it usually as chilled water, or ice.
“During daytime, when electricity is more expensive, the chiller turns off and the stored cooling is used to meet the building’s cooling load requirements,” he adds.
Further, Ball points out that the hospital operates a water-cooled ice bank system.
“The thermal storage system’s water tower’s variable-speed drives ensure that, as the hospital’s cooling load diminishes, the chillers start operating in load-shifted mode through the use of the ice bank system,” Airco national sales manager Andrew Ross explains.
“The systems will be interfaced using control systems,” he states, adding that the chillers are critical to ensure the prevention of bacteria spreading in the hospital.
Rising Electricity Costs Driving Innovation
Ross says, although these heating and cooling technologies have been in use in Europe and North America for several decades, they have become available in South Africa only in the last five years.
Ball adds that significant local demand for advanced heat exchanger and thermal storage systems did not exist, as “electricity was relatively cheap”.
“However, with increasing energy prices, many companies want to implement energy efficient solutions for their operations.”
Additionally, he points out that companies that are using older technologies are retrofitting their operations to ensure that the new systems are energy efficient.
Ball points out that the heat recovery and thermal storage systems are being used in several other hospitals and health training facilities, such as private fitness and healthcare company Vivagym’s gym in Hillfox, Roodepoort, on the West Rand.
“Owing to increased awareness of . . . electricity costs, the fragile state of State-owned power utility Eskom’s grid and incentives to achieve green star ratings for environment-friendly buildings, we are receiving more enquiries about our offerings for new build and retrofit projects.
“I believe that, owing to these factors, Airco will likely achieve increased sales figures over the next three to five years,” Ball concludes.