Hi -
"Just the facts, ma'am..."
My brother has a 10,000 gallon uncovered shaded pool at his personal and rental home in Mexico with a Pentair Intelliflo VSF pump, Hayward Pro Series 3.1 sq.ft. sand filter and a 480 sq.ft. roof-mounted solar hot water array three stories above the pool. The solar array works great, but he also employs an old Mass brand "Mass Ter Cal 150" gas heater to make up for heat loss due to cool winter nighttime temps (for rental clients who like a dip first thing in the morning).
The gas heater had been plumbed in years ago with 1" copper pipe, but recently a local provider swapped out the copper pipe for 1.5" CPVC (as spec'd by the manufacturer). Both the old copper and new CPVC pipes had/have (in addition to the elbows common to all flow paths) a total of eight additional 90-degree elbows in the intake and outflow paths, due to the layout of the components located in a small underground equipment room adjacent to the pool. The pump is roughly four feet lower than the water surface of the pool. The gas heater is adjacent to the pool pump.
I came down to visit recently and upon inspection we wondered if the gas heater was excessively restricting water flow.
With the pump in filter mode and bypassing the solar and gas heating systems, the pump consumes about 145 watts at a 20 gpm pump setting. This seems reasonable to me.
With the solar panels enabled, the pump consumes around 300 watts. This too seems reasonable considering the height of the panels, the 1.5" feed and return PVC pipe sizes, and a fair number of elbows in the flow path. As I mentioned, the solar panel system functions very well.
However, when we close the gas heater bypass valve to route water ONLY through the gas heater, the pump electrical consumption rises to 525 watts at 20 gpm, up from 145 watts when the heater is bypassed. (20 gpm is the minimum flow specified by the heater manufacturer).
My brother tells me this seems to be significantly higher electrical consumption than he recalls before the 1" copper pipe was replaced with 1.5" CPVC. The pump is audibly working hard to maintain the specified flow and he says he does not recall that being the case previously. (We agree that memory can't always be trusted in such things...)
The plumbing appears to be correct. My question is whether there may be excessive restriction in the heat exchange unit. I can't imagine that the manifold would restrict the water flow to such a large degree unless it was somehow clogged by material introduced during the pipe replacement project...or...?
Could someone advise whether this power-consumption number seems sane (considering the eight additional 90-degree elbows in the heater flow path) before we decide to open up the heat-exhange unit ("intercambiador" in Spanish) for inspection? We're hesitant to dive into that project only because we'd have to procure the necessary replacement gaskets for the old unit and don't want to have to do that unless we're sure that's the next step.
Thanks for any and all advice and assistance.
"Just the facts, ma'am..."
My brother has a 10,000 gallon uncovered shaded pool at his personal and rental home in Mexico with a Pentair Intelliflo VSF pump, Hayward Pro Series 3.1 sq.ft. sand filter and a 480 sq.ft. roof-mounted solar hot water array three stories above the pool. The solar array works great, but he also employs an old Mass brand "Mass Ter Cal 150" gas heater to make up for heat loss due to cool winter nighttime temps (for rental clients who like a dip first thing in the morning).
The gas heater had been plumbed in years ago with 1" copper pipe, but recently a local provider swapped out the copper pipe for 1.5" CPVC (as spec'd by the manufacturer). Both the old copper and new CPVC pipes had/have (in addition to the elbows common to all flow paths) a total of eight additional 90-degree elbows in the intake and outflow paths, due to the layout of the components located in a small underground equipment room adjacent to the pool. The pump is roughly four feet lower than the water surface of the pool. The gas heater is adjacent to the pool pump.
I came down to visit recently and upon inspection we wondered if the gas heater was excessively restricting water flow.
With the pump in filter mode and bypassing the solar and gas heating systems, the pump consumes about 145 watts at a 20 gpm pump setting. This seems reasonable to me.
With the solar panels enabled, the pump consumes around 300 watts. This too seems reasonable considering the height of the panels, the 1.5" feed and return PVC pipe sizes, and a fair number of elbows in the flow path. As I mentioned, the solar panel system functions very well.
However, when we close the gas heater bypass valve to route water ONLY through the gas heater, the pump electrical consumption rises to 525 watts at 20 gpm, up from 145 watts when the heater is bypassed. (20 gpm is the minimum flow specified by the heater manufacturer).
My brother tells me this seems to be significantly higher electrical consumption than he recalls before the 1" copper pipe was replaced with 1.5" CPVC. The pump is audibly working hard to maintain the specified flow and he says he does not recall that being the case previously. (We agree that memory can't always be trusted in such things...
)The plumbing appears to be correct. My question is whether there may be excessive restriction in the heat exchange unit. I can't imagine that the manifold would restrict the water flow to such a large degree unless it was somehow clogged by material introduced during the pipe replacement project...or...?
Could someone advise whether this power-consumption number seems sane (considering the eight additional 90-degree elbows in the heater flow path) before we decide to open up the heat-exhange unit ("intercambiador" in Spanish) for inspection? We're hesitant to dive into that project only because we'd have to procure the necessary replacement gaskets for the old unit and don't want to have to do that unless we're sure that's the next step.
Thanks for any and all advice and assistance.
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