Resetting Steam Pressure

BFlanzbaum

I need a little education. Dan always says lower the pressure on a steam system.

Have a 2 story school with unit ventilators. They have installed a Heat Timer modulating control that modulates the gas valves. 2 boilers. I don't get it. If it is lowering the pressure form 5 to 2 or 3 i understand that they will burn less fuel but wont the supply air stay the same? Isn't 212 degrees 212 degrees?

If someone could give me a brief explanation that would be great

Thanks in advance for any input

JStar

Steam

Higher pressure = Higher temperature.



You will save fuel with modulation. The idea is that you start in high fire, then when all of the mains and pipes are hot, you step down, because you only need to then heat the radiators or unit heaters. The main pressure should be set just high enough to overcome the highest friction loss in the system, or to lift any condensate if needed.