With sustainability being the focus, various methods are being adopted in HVAC systems to improve the efficiency and thereby reduce the carbon footprint.
Heat Recovery units provide free heating which can be used in pharmaceutical applications, hospitality segment, boiler integration etc. This helps in better overall efficiency of the system and reduces/eliminates the need of other types of systems needed to generate heating
Basically, Heat Recovery Units save energy by utilizing waste heat from a chilled water system to meet building/process needs.
Condenser heat, which is otherwise disposed to the environment, can be used for many purposes, including Space heating, Domestic water heating, Laundry, process heat applications etc.
Normal chiller will reject the condenser heat to environment. In recovery chiller, we introduce additional heat exchanger / circuit to generate hot water, thereby improving the efficiency and reduced dissipated heat to environment
There are different configuration of Heat Recovery Units:
Partial Heat Recovery unit: Heat can be recovered to the extent of approx 20% of chiller capacity
Total Heat Recovery: heat can be recovered equivalent to 100% of chiller capacity.
Hot water upto 60°C can be generated.
The design criteria to be considered for Heat Recovery:
Different combination of operation/application
Capturing sufficient heat for useful purposes
Minimize chiller lift and maximize chiller efficiency
Hot water temperature control without affecting stable chiller plant operation
Hot water can be used for many purposes in the building and for process applications i.e. for heating the building, process in pharma segment, kitchen and guest rooms in hospitality segment and/or as boiler feed water and also in some manufacturing applications.
Heat Recovery system will not only provide free cooling to the building needs but also improves the efficiency.
Normally the system efficiency will be expressed in COP (Coefficient of performance)
For cooling Application COP = cooling capacity (KW) / Power input(KW)
For Heating Application COP = heat rejection (KW) / Power input (KW)
This combined efficiency can contribute to reducing the whole building energy consumption
Its suggested to have external automation control , which can control entire hot water plant + chiller mode of operation.