Hello everyone. Been lurking here for awhile and now have my own questions.
I currently have a single-speed pump that uses a lot of electricity and is oversized for running just the spa. (I get a ~10 PSI increase when I close off all supply lines except the 5 spa jets that are fed from a single 2" pipe.) So I'm looking at replacing the pump with a variable speed one to solve both problems.
As part of the process, I measured all of the pipe runs and since I can't see underground, assumed 90-degree elbows everywhere. At 70 GPM, this gives me a figure of 127 feet of head, which seems to be off the charts for every pump I've looked at. So do I need to re-check my math, or buy pressure & vacuum gauges and read the numbers off of the existing pump? (If total dynamic head is even the same thing as pipe friction head loss.)
I currently have a single-speed pump that uses a lot of electricity and is oversized for running just the spa. (I get a ~10 PSI increase when I close off all supply lines except the 5 spa jets that are fed from a single 2" pipe.) So I'm looking at replacing the pump with a variable speed one to solve both problems.
As part of the process, I measured all of the pipe runs and since I can't see underground, assumed 90-degree elbows everywhere. At 70 GPM, this gives me a figure of 127 feet of head, which seems to be off the charts for every pump I've looked at. So do I need to re-check my math, or buy pressure & vacuum gauges and read the numbers off of the existing pump? (If total dynamic head is even the same thing as pipe friction head loss.)