Pressure needed for solar pool heating

[d***@XPressureX.usenet.us.com]

I want to add solar heat to my pool.
My original intent was to add a solar powered pump, like the El Sid
included with the domestic water heaters from solarroofs.com
I've been led to believe that would not be enough pump for rooftop pool
collectors, and now I wonder if the existing 1.0 HP pool pump is large
enough. I don't think so.

I did some pressure checks.
With the pressure gauge indicating 19 psi backpressure from my DE filter,
it was time for a backflush. I connected my poolvac hose to the outlet
into the pool. It would only push water up about 5 feet above pool level.

With my waste hose connected, I could push water well above the roof
height. As I raised my waste hose, and then plugged it completely as a
check, it appears that my 1HP pump is producing a maximum of 22PSI.
That might be internally regulated, as the DE filter is rated for a maximum
of 25psi.

With a freshly loaded DE filter, my backpressure is 11psi. That would be
25 feet of lift tied in at a point after a clean DE filter. The DE
backpressure rises to about 15psi during a few hours run, and drops off
when the pump shuts off. The next day, the pressure is back down to 11psi.

If I am correct, when the backpressure reaches 15psi, I have 7 psi left to
push water to the roof. That's 15 feet, which would barely be the top of
the roof, and there would be almost no flow at that point.

If I wait until my normal backflush time of 19-20psi, I only have 3 psi
available from the pump, and water would not reach the solar collector.

There isn't much mention of pressure on the pool heating web sites, except
for powermat, and that one is not clear to me.

[SJC]

Post by d***@XPressureX.usenet.us.com
I want to add solar heat to my pool.
My original intent was to add a solar powered pump, like the El Sid
included with the domestic water heaters from solarroofs.com
I've been led to believe that would not be enough pump for rooftop pool
collectors, and now I wonder if the existing 1.0 HP pool pump is large
enough. I don't think so.
I did some pressure checks.
With the pressure gauge indicating 19 psi backpressure from my DE filter,
it was time for a backflush. I connected my poolvac hose to the outlet
into the pool. It would only push water up about 5 feet above pool level.
With my waste hose connected, I could push water well above the roof
height. As I raised my waste hose, and then plugged it completely as a
check, it appears that my 1HP pump is producing a maximum of 22PSI.
That might be internally regulated, as the DE filter is rated for a maximum
of 25psi.
With a freshly loaded DE filter, my backpressure is 11psi. That would be
25 feet of lift tied in at a point after a clean DE filter. The DE
backpressure rises to about 15psi during a few hours run, and drops off
when the pump shuts off. The next day, the pressure is back down to 11psi.
If I am correct, when the backpressure reaches 15psi, I have 7 psi left to
push water to the roof. That's 15 feet, which would barely be the top of
the roof, and there would be almost no flow at that point.
If I wait until my normal backflush time of 19-20psi, I only have 3 psi
available from the pump, and water would not reach the solar collector.
There isn't much mention of pressure on the pool heating web sites, except
for powermat, and that one is not clear to me.
--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

I am not sure you would want to use the Fireball collectors for pool heating.
The pool heating panels have a much larger manifold that will take the larger
flows required for pool heating.

[d***@XReXXPress.usenet.us.com]

Post by SJC

I want to add solar heat to my pool. My original intent was to add a
solar powered pump, like the El Sid included with the domestic water
heaters from solarroofs.com

I am not sure you would want to use the Fireball collectors for pool
heating. The pool heating panels have a much larger manifold that will
take the larger flows required for pool heating.

Right. Not the Domestic Water Heater panels, but a with a similar scheme
for the pump, PV is available when the solar heat is available.

I would need 200sf of panel, 2-5gpm, at a 12 foot lift from the pool.
I need to figure out how much pump that requires, because I don't think my
existing 1hp is up to the task, after my DE filter.

[Gary]

Post by d***@XPressureX.usenet.us.com
I want to add solar heat to my pool.
My original intent was to add a solar powered pump, like the El Sid
included with the domestic water heaters from solarroofs.com
I've been led to believe that would not be enough pump for rooftop pool
collectors, and now I wonder if the existing 1.0 HP pool pump is large
enough. I don't think so.
I did some pressure checks.
With the pressure gauge indicating 19 psi backpressure from my DE filter,
it was time for a backflush. I connected my poolvac hose to the outlet
into the pool. It would only push water up about 5 feet above pool level.
With my waste hose connected, I could push water well above the roof
height. As I raised my waste hose, and then plugged it completely as a
check, it appears that my 1HP pump is producing a maximum of 22PSI.
That might be internally regulated, as the DE filter is rated for a maximum
of 25psi.
With a freshly loaded DE filter, my backpressure is 11psi. That would be
25 feet of lift tied in at a point after a clean DE filter. The DE
backpressure rises to about 15psi during a few hours run, and drops off
when the pump shuts off. The next day, the pressure is back down to 11psi.
If I am correct, when the backpressure reaches 15psi, I have 7 psi left to
push water to the roof. That's 15 feet, which would barely be the top of
the roof, and there would be almost no flow at that point.
If I wait until my normal backflush time of 19-20psi, I only have 3 psi
available from the pump, and water would not reach the solar collector.
There isn't much mention of pressure on the pool heating web sites, except
for powermat, and that one is not clear to me.

HI,
I don't know much about pool plumbing, but is there not some way to plumb in the
line to the solar collectors before the filter so that the collectors have the
full pump pressure available to them? It seems like 22 psi should be plenty?

You might find something in the Home Power solar pool heating basics articles
that would help: http://www.builditsolar.com/Projects/PoolHeating/pool_heating.htm



Gary

[d***@XReXXPress.usenet.us.com]

Post by Gary
I don't know much about pool plumbing, but is there not some way to plumb
in the line to the solar collectors before the filter so that the
collectors have the full pump pressure available to them? It seems like
22 psi should be plenty?

I think the charts and some email from powermat.com have confused me.
It seems simple enough to me, but powermat spends a lot of time on the web
site about how everyone is wrong about the need for pressure.

Yes. I think I would tap off before the filter, where pressure varies from
11 to 20 psi, as the filter acts as a variable pressure regulator, and
return downstream from the filter, where I think there is no backpressure,
but that needs to be confirmed, and may be the place that powermat is
saying needs to be verified as low pressure.

I'm also not sure if I need a filter in that line to protect the solar
panels.

Post by Gary
You might find something in the Home Power solar pool heating basics
http://www.builditsolar.com/Projects/PoolHeating/pool_heating.htm

I went through the various articles noted there.
The first one shows the system that Powermat says is wrong, that you don't
want all of the flow going through the panels. That is also after the
filter, where I don't think I have enough pressure.

I think I need to go before the filter, but then as the filter clogged, the
panels would become the easy route, so I would need a pressure regulator
on that line. That's where my math falls apart.

I also haven't verified that the initial 11psi backpressure is all from the
filter. Powermat indicates that the plumbing back to the pool is often
restrictive. I need to "filter to waste" thought a short 1-1/4" line to
check that.

Your list might be where I first found powermat, and I wonder if you have
reviewed their materials, or are just referencing them?

They definitely spend more time talking about pressure than anyone else,
but I think some of what is there is incorrect.




I had a visitor to my PV setup over the weekend, and yours was one of
the web pages that I printed out for his reference moving forward with an
off-the-grid solar PV installation.

Thanks.

[Gary]

Hi,
I did a little more looking around on the pump issue, and found one source that
reccomended putting a filter in that has lower back pressure. They suggested
using a filter that is sized for about 50% more than your actual pool volume.
Not sure it thats the best way, but its something to think about.

Gary

Post by Gary

Post by d***@XPressureX.usenet.us.com
I want to add solar heat to my pool.
My original intent was to add a solar powered pump, like the El Sid
included with the domestic water heaters from solarroofs.com
I've been led to believe that would not be enough pump for rooftop pool
collectors, and now I wonder if the existing 1.0 HP pool pump is large
enough. I don't think so.
I did some pressure checks.
With the pressure gauge indicating 19 psi backpressure from my DE filter,
it was time for a backflush. I connected my poolvac hose to the outlet
into the pool. It would only push water up about 5 feet above pool level.
With my waste hose connected, I could push water well above the roof
height. As I raised my waste hose, and then plugged it completely as a
check, it appears that my 1HP pump is producing a maximum of 22PSI.
That might be internally regulated, as the DE filter is rated for a maximum
of 25psi.
With a freshly loaded DE filter, my backpressure is 11psi. That would be
25 feet of lift tied in at a point after a clean DE filter. The DE
backpressure rises to about 15psi during a few hours run, and drops off
when the pump shuts off. The next day, the pressure is back down to 11psi.
If I am correct, when the backpressure reaches 15psi, I have 7 psi left to
push water to the roof. That's 15 feet, which would barely be the top of
the roof, and there would be almost no flow at that point.
If I wait until my normal backflush time of 19-20psi, I only have 3 psi
available from the pump, and water would not reach the solar collector.
There isn't much mention of pressure on the pool heating web sites, except
for powermat, and that one is not clear to me.

HI,
I don't know much about pool plumbing, but is there not some way to plumb in the
line to the solar collectors before the filter so that the collectors have the
full pump pressure available to them? It seems like 22 psi should be plenty?
You might find something in the Home Power solar pool heating basics articles
http://www.builditsolar.com/Projects/PoolHeating/pool_heating.htm
Gary

[Gary]

Post by Gary
Hi,
I did a little more looking around on the pump issue, and found one source that
reccomended putting a filter in that has lower back pressure. They suggested
using a filter that is sized for about 50% more than your actual pool volume.
Not sure it thats the best way, but its something to think about.
Gary

This installation manual from SolarEnergy.com has a discussion on pump
horsepower, filter resistance, and booster pumps (if needed):
http://www.solarenergy.com/specs/sunhom_pool/pool_install_manual.pdf

Gary

Post by Gary

Post by Gary

Post by d***@XPressureX.usenet.us.com
I want to add solar heat to my pool.
My original intent was to add a solar powered pump, like the El Sid
included with the domestic water heaters from solarroofs.com
I've been led to believe that would not be enough pump for rooftop pool
collectors, and now I wonder if the existing 1.0 HP pool pump is large
enough. I don't think so.
I did some pressure checks.
With the pressure gauge indicating 19 psi backpressure from my DE filter,
it was time for a backflush. I connected my poolvac hose to the outlet
into the pool. It would only push water up about 5 feet above pool level.
With my waste hose connected, I could push water well above the roof
height. As I raised my waste hose, and then plugged it completely as a
check, it appears that my 1HP pump is producing a maximum of 22PSI.
That might be internally regulated, as the DE filter is rated for a maximum
of 25psi.
With a freshly loaded DE filter, my backpressure is 11psi. That would be
25 feet of lift tied in at a point after a clean DE filter. The DE
backpressure rises to about 15psi during a few hours run, and drops off
when the pump shuts off. The next day, the pressure is back down to
11psi. If I am correct, when the backpressure reaches 15psi, I have 7
psi left to
push water to the roof. That's 15 feet, which would barely be the top of
the roof, and there would be almost no flow at that point.
If I wait until my normal backflush time of 19-20psi, I only have 3 psi
available from the pump, and water would not reach the solar collector.
There isn't much mention of pressure on the pool heating web sites, except
for powermat, and that one is not clear to me.

HI,
I don't know much about pool plumbing, but is there not some way to plumb in the
line to the solar collectors before the filter so that the collectors have the
full pump pressure available to them? It seems like 22 psi should be plenty?
You might find something in the Home Power solar pool heating basics articles
http://www.builditsolar.com/Projects/PoolHeating/pool_heating.htm
Gary

--
Gary

www.BuildItSolar.com
***@BuildItSolar.com
"Build It Yourself" Solar Projects









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[d***@XReXXPress.usenet.us.com]

Post by Gary
Hi,
I did a little more looking around on the pump issue, and found one
source that reccomended putting a filter in that has lower back pressure.
They suggested using a filter that is sized for about 50% more than your
actual pool volume. Not sure it thats the best way, but its something to
think about.

That would be sensible.

Powermat.com just tells me that I'm wrong about my pressure readings, or
that there is something wrong with my filter.

He suggests that you should have a lower HP pump, trying to push less
volume. The result would be longer run times, resulting in better water
clarity and lower power consumption overall. That part sounds good if it's
true. But the industry seems not to agree with him, according to his web
pages.

I'll take a look at
http://www.solarenergy.com/specs/sunhom_pool/pool_install_manual.pdf
I'm inclined to run a separate pump, controlled by a temperature
differential controller. If it weren't for the clogging of the DE filter,
I'd be okay with the one I have, but clogging is a bi-weekly norm.

Today, just the solar cover has the water temp very high for the first inch
or so at the surface, but a solar collector on the roof will be a good
thing.

I was off for a week, exploring the water temperatures in the Bahamas ;-)