Danfoss Logo
Home Sitemap Worldwide
Drives Overview
Technical Notes
Fast Path

Secondary Pumping - New Standard

Application Description | Traditional solution | Energy Savings
Click here to read more about: AEO, PID Control, VVC plus, Sleep Mode

New Standard
In primary/secondary pumping systems, great energy savings and control potential is realized by adding adjustable frequency drives to control the secondary system, changing it from constant speed, variable volume to variable speed, variable volume. With drives applied, the pumps are controlled to vary their speed with the system requirements (the system curve) instead of simply "riding" the pump curve. This results in operation following the system curve, optimum energy savings and eliminates the over-pressurization of the cooling coil two-way control valves. With reduced speed, life of the pump and motor bearings are increased. Although the same cooling coil differential head is maintained in the individual air handling units, the overall system pressure and control valve pressure difference is reduced. The resulting water velocity across the valve seat is significantly lower than if the pump were operating at constant, maximum speed. This increases valve life, reduces maintenance effort and reduces noise in the system.

Click on graphic to animate!

Previous     Next