Dan Holohan: Still learning
"Our problem is that five out of hundreds of univentilator coils freeze up on a regular basis. They are part of two pipe steam systems with pneumatic control valves and condensate pumps. The F&T traps have been replaced and the coils are grading down to the returns. The traps on some are two feet or so below the coil outlet. The boiler pressure on all buildings runs between 4 psi and 8 psi and the boiler shuts down at night until the coldest room in the building requires heat. If the ou...
Source: supplyht.com