BTU (British Thermal Unit)
The British thermal unit (BTU) is a unit of energy used in the power, steam generation, heating and air-conditioning industries. In scientific contexts the BTU has largely been replaced by the SI unit of energy, the joule [J].
A buffer tank is a storage tank used on the cold user side of an air-conditioning system. The tank is used as storage to cover peak loads or in situations when a surge in demand exceeds the capacity of the cooling system.
A butterfly valve is from a family of valves called quarter-turn valves. The butterfly is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway.
Calculation of flow
In order to calculate pressure loss in a heating or cooling system it is essential to know the volume flow rate Q. The volume flow rate is based on heat demand, temperature difference, specific energy capacity, and density.