Working with

Heating hot water systems

Heating Hot Water (HHW) systems provide heating both for space heating as well as process heating for many industries. HHW boilers are typically fired by natural gas, although some older systems may still use fuel oil. Some HHW systems use a steam to HHW generator (heat exchanger) in lieu of a dedicated HHW boiler. Boilers range in size from small dedicated units, to larger units for central systems. Sometimes smaller boilers are placed in groups to provide for large central systems. HHW distribution systems can range from simple primary constant speed pumping, to primary/secondary (or even tertiary for large systems), to the more modern variable primary pumping systems.

Typical system issues include:

1) Low supply/return temperature temperature differential

2) Insufficient heating capacity, particularly in older systems

3) Imbalance between cooling and flow rates

4) Flow distribution problems in larger systems

5) Controls/sequence of operations no longer applicable to current system