HVAC

Heating, Ventilation and Air Conditioning (HVAC) involves removal of heat from a confined space and at the same time controls humidity and quality of air inside the confined space as per requirement. Refrigeration deals with the pumping out of heat, from a low-temperature heat source to a high- temperature heat sink, by using a low boiling temperature refrigerant. Both HVAC and refrigeration system transfers the heat energy from or to the products, or building environment. The cooling effect produced is quantified in tons of refrigeration (TR). 

One ton of refrigeration is the amount of heat extracted to produce one ton of ice at 0 °C from water at 0 °C in 24 hours.

For energy saving tips 

https://www.eec-fncci.org/page/improving-hvac-efficiency