Question:
Currently I have a 3/4 HP Hayward pump with a sand filter. To use this
>solar system I will have to pump the water 12 feet horizontally and 15 feet
>vertically to reach the roof of my house (which is where the solar heaters
>will be). Is a 3/4 HP pump strong enough to do this? The vendors website
>says that a 1HP is plenty for this application, but doesn't say anything
>specifically for any smaller pumps. I do run this pump 24 hours/day during
>the summer so the smaller the pump, the less expensive it is to run the
>pool. Any experiences or thoughts out there?
Answer:
I have a 3/4 HP (full rated) Hayward Super II pump, 1-1/2 inch pipes,
and oversize sand filter for a 22,000 gal pool with a similar lift to
the solar panels. It works OK but I generally can't get flow if I'm
connected to the solar panels when I start up. I have to start
pumping direct to the pool before manually swapping to the solar
panels. Air leaks that allow water to drain back down to pool level
when the pump is off are a killer. If you can keep water in the line
from pool to pump, you may be fine. The system is marginal. Running
24/7 obviously avoids my unattended startup problems.
What you need to consider is the pump design. The pump mechanism may
be designed as either a high flow - low head pump which is not good
for lifting to solar panels, or a medium flow - high head pump. You
would need to check the pump curves for your model. Here is a link to
a set of Hayward pump curves.
