Pumping question for Metric Radiant Pool

[arthurdent]

We are having a Radiant Metric 27-foot round installed. (18,600 gallons) Pentair pallet system with 1.0 hp pump and the 19 sand dollar filter.

I believe the pump and filter have 1.5-inch pipe connections. The skimmer will accept what sized pipe? The pump curve reads 12 psi at the filter equaling 40 GPM., turnover rate x 3 daily. The filter max is 40 GPM.

The pump/filter will be about 20 feet from the pool. I am thinking about going up to 2" schedule 40 from the skimmer to intake then adapting to pump and filter then back to 2".

Now for the confounding issue. I am constructing a DIY ground-mounted glazed solar heater. If I need more than one-panel system I will hook them in parallel. Each panel will have roughly 500 feet of 1/2" coiled poly irrigation hose hooked in series. (Rainbird). There will be about a 7-foot total height rise then fall back to the return side 2" manifold. (8-foot-long panel at a 40* tilt with some ground clearance. Preliminary research I did speculates at the calculated 12 psi I would have a flow rate of 3 GPM? I will have the first panel built and mounted in 3 days. I then can post with the actual BTU equivalents, flow rates, temp rises, and other data and pictures if requested.

Can I put a diverter valve in the proposed intake line prior to the 1 hp pump to feed the solar panel directly? 1.5 or 2-inch line here? Some websites suggest a 1.5" intake will handle 42 GPM and others 52 GPM??? If the skimmer accepts only a 1.5" pipe and I then upsize to a 2" pipe the rest of the way do I use the 42 GPM rate or the 2" 73 GPM service or some number inbetween? Cavitation= bad.

Finally, return the heated water to the discharge side of the filter and then mixed the water back into the pool inlet? Backflow valves needed? And how much head to add per bf valve?

Other options:: I have a 3/4 hp pool pump already. And a booster pump. (80 psi pressure rise! too much I think). Would it be better to use the 3/4 pump as a dedicated system for the solar heater using a bypass valve to control the solar flow rate and therefore the "heating time" in the solar complex? Then simply drop the heated and unheated return water over the side of the pool.?

Occam's razor leads to the second engineering solution. However, there is the extra electricity cost. AND how to get water to the intake side of the 3/4 pump. I am reluctant to drop a 120-volt sump pump into the pool. (AC electricity plus water plus electrolytes gives me pause). Aftermarket surgery on a pool with a lifetime warranty also makes me cautious.

Creative ideas, thoughts, and best wishes are all invited.

Thank you for taking the time to read my lengthy post!!!!

 

[mknauss]

Welcome to the forum.
Let's ask @mas985 for some assistance in all this plumbing and pump sizing discussion.

 

[mas985]

I believe the pump and filter have 1.5-inch pipe connections. The skimmer will accept what sized pipe?

If the skimmer came with the pool, it should also be 1.5"

The pump curve reads 12 psi at the filter equaling 40 GPM., turnover rate x 3 daily. The filter max is 40 GPM.

First, head loss is both post filter and pre-filter including the suction side. So you cannot determine flow rate from only the filter pressure.
Second, turnovers are not a good measure for pool maintenance. In the winter, I run about 1/4 turn per day and summer about 1/2 turn per day. Turnovers really don't matter much to pool maintenance.

Now for the confounding issue. I am constructing a DIY ground-mounted glazed solar heater. If I need more than one-panel system I will hook them in parallel. Each panel will have roughly 500 feet of 1/2" coiled poly irrigation hose hooked in series. (Rainbird). There will be about a 7-foot total height rise then fall back to the return side 2" manifold. (8-foot-long panel at a 40* tilt with some ground clearance. Preliminary research I did speculates at the calculated 12 psi I would have a flow rate of 3 GPM? I will have the first panel built and mounted in 3 days. I then can post with the actual BTU equivalents, flow rates, temp rises, and other data and pictures if requested.

Glazed panels are less efficient during air temperature warmer than the water and more efficient with cold air temperatures. Is that really what you are after?

Second, 500' of 1/2" tubing has a capture area of only about 25 sq-ft which is not much for solar gain. At best on perfectly sunny day, each panel will add only about 0.25F to the pool temperature.

Can I put a diverter valve in the proposed intake line prior to the 1 hp pump to feed the solar panel directly? 1.5 or 2-inch line here? Some websites suggest a 1.5" intake will handle 42 GPM and others 52 GPM??? If the skimmer accepts only a 1.5" pipe and I then upsize to a 2" pipe the rest of the way do I use the 42 GPM rate or the 2" 73 GPM service or some number inbetween? Cavitation= bad.

The flow rate is determined by total head loss. The lower the head loss, the higher the flow rates. Flow rate is not fundamentally limited by pipe diameter although smaller pipe diameter will create more head loss. However, it is always a good idea to limit flow velocity in pipe to keep head loss in check. So most will recommend no more than 8 ft/sec for return pipe and 6 ft/sec for suction pipe.

But in general, unless you do a detailed head loss calculation, you really won't know what your flow rates will be.

Finally, return the heated water to the discharge side of the filter and then mixed the water back into the pool inlet? Backflow valves needed? And how much head to add per bf valve?

There should be a check valve after the filter before going to solar and then another check valve on solar return.

Other options:: I have a 3/4 hp pool pump already. And a booster pump. (80 psi pressure rise! too much I think). Would it be better to use the 3/4 pump as a dedicated system for the solar heater using a bypass valve to control the solar flow rate and therefore the "heating time" in the solar complex? Then simply drop the heated and unheated return water over the side of the pool.?

I would use just a single pump for both solar and without solar and use an automated solar control valve with controller to turn solar on and off on demand.

Occam's razor leads to the second engineering solution. However, there is the extra electricity cost. AND how to get water to the intake side of the 3/4 pump. I am reluctant to drop a 120-volt sump pump into the pool. (AC electricity plus water plus electrolytes gives me pause). Aftermarket surgery on a pool with a lifetime warranty also makes me cautious.

What is this for?

 

[RadiantMike]

We are having a Radiant Metric 27-foot round installed. (18,600 gallons) Pentair pallet system with 1.0 hp pump and the 19 sand dollar filter.

I believe the pump and filter have 1.5-inch pipe connections. The skimmer will accept what sized pipe? The pump curve reads 12 psi at the filter equaling 40 GPM., turnover rate x 3 daily. The filter max is 40 GPM.

The pump/filter will be about 20 feet from the pool. I am thinking about going up to 2" schedule 40 from the skimmer to intake then adapting to pump and filter then back to 2".

Now for the confounding issue. I am constructing a DIY ground-mounted glazed solar heater. If I need more than one-panel system I will hook them in parallel. Each panel will have roughly 500 feet of 1/2" coiled poly irrigation hose hooked in series. (Rainbird). There will be about a 7-foot total height rise then fall back to the return side 2" manifold. (8-foot-long panel at a 40* tilt with some ground clearance. Preliminary research I did speculates at the calculated 12 psi I would have a flow rate of 3 GPM? I will have the first panel built and mounted in 3 days. I then can post with the actual BTU equivalents, flow rates, temp rises, and other data and pictures if requested.

Can I put a diverter valve in the proposed intake line prior to the 1 hp pump to feed the solar panel directly? 1.5 or 2-inch line here? Some websites suggest a 1.5" intake will handle 42 GPM and others 52 GPM??? If the skimmer accepts only a 1.5" pipe and I then upsize to a 2" pipe the rest of the way do I use the 42 GPM rate or the 2" 73 GPM service or some number inbetween? Cavitation= bad.

Finally, return the heated water to the discharge side of the filter and then mixed the water back into the pool inlet? Backflow valves needed? And how much head to add per bf valve?

Other options:: I have a 3/4 hp pool pump already. And a booster pump. (80 psi pressure rise! too much I think). Would it be better to use the 3/4 pump as a dedicated system for the solar heater using a bypass valve to control the solar flow rate and therefore the "heating time" in the solar complex? Then simply drop the heated and unheated return water over the side of the pool.?

Occam's razor leads to the second engineering solution. However, there is the extra electricity cost. AND how to get water to the intake side of the 3/4 pump. I am reluctant to drop a 120-volt sump pump into the pool. (AC electricity plus water plus electrolytes gives me pause). Aftermarket surgery on a pool with a lifetime warranty also makes me cautious.

Creative ideas, thoughts, and best wishes are all invited.

Thank you for taking the time to read my lengthy post!!!!

I have a 24 metric Radiant pool. I run a 2 HP Hayward pump and a 150 sqft cartridge filter. I have a Natures2 in-line sanitization system (a must have). My entire system is 1-1/2 schedule 40 PVC with no down size points. You need to get rid of any fitting that accept 1-1/4 and 1-1/2 hoses as they will restrict flow to 1-1/4" even if you attach a 1-1/2" hose. I have shut-off valves at the pool inlet and outlet plus the filter backflow port for easy maintenance. I also have valves installed on the heater manifold so I can bypass the heater when shocking the pool or adding chemicals. I never have algae or water issues running this set-up. Here's a picture...