Slow and steady
There are many other benefits that come from utilizing a VSP and pumping water slower, or at a specific flow rate, such as:
- Each piece of pool or spa equipment that has a recommended flow rate for operation can be set for a specific speed and time;
- Running water slower through the filter will typically capture smaller particles;
- Better distribution of chemicals since the pump is running for a longer period of time;
- Reduced Total Dynamic Head (TDH) helps decrease equipment wear and tear; and
- Quieter operation.
Installation tips
When installing a VSP on a new swimming pool, care should be taken by builders to ensure proper pipe and equipment sizing is used to handle the pump’s required maximum flow rate. For existing pools, it is important to verify the pump’s maximum flow rate will not exceed the capacity of the existing circulation system and equipment. However, keep in mind the pipe length between the pump’s suction port and first elbow or fitting should be at least five times the pipe size.
Programming tips
It has already been stated that running the pump for longer periods of time at the lowest speed will save the most money.
When determining the minimum and maximum speeds for a given system the guidelines are easy. For maximum speed, cavitation (the loss of pressure in flowing liquid, which can damage moving parts) can be beneficial.
Ramping up the VSP’s speed until the pump cavitates can help identify its upper limit of speed. The lower limit should be able to run any piece of equipment that requires a specific speed during circulation, e.g. salt cell generator requirements. It is also important to make sure the filter fills completely with water to avoid filtration problems. To verify this, make sure water comes out of the filter’s air relief valve.
John Ott has been with Hayward Pool Products in Pomona, Calif., for 26 years. His experience in the swimming pool industry expands 37 years and includes experience in service, construction and retail. He can be reached via e-mail at jott@haywardnet.com.
