Heat from bottom or sides?

[SuperMiguel]

Hello, when my pool was been build my PB made a huge deal about how this pool had returns on the bottom for heating... Im now wondering if this is true or not really... Basically i have returns on the sides (top) and on the bottom, should i heat it from the bottom returns, side ones or both? Or doesnt really matter? Thanks!

 

[1poolman1]

If you can isolate the bottom returns while heating, the water will heat more uniformly, bottom to top, but not necessarily faster. A pool with good circulation will, eventually, warm the whole body of water.
Yes, there are all kinds of heat-loss calculations that can be considered, but they don't really apply in a "real-world" situation. It takes a certain amount of BTUs to heat to a certain temp, regardless of where the water enters the pool.

 

[SuperMiguel]

If you can isolate the bottom returns while heating, the water will heat more uniformly, bottom to top, but not necessarily faster.

Yes currently i can do either top or bottom or both at the same time

 

[1poolman1]

Yes currently i can do either top or bottom or both at the same time

If I had that option, I would always bias the return more to the floor to get better chemical circulation, forcing more (but not all) filtered water to the bottom while pulling the surface water through the skimmer.

 

[ajw22]

Does not really matter.

Try it both ways and see if you see any difference.

I doubt you will.

 

[JWeiss]

Took me a while to figure out that my pool (built by previous owner) was fitted with the Mark Urban flow reversal system. It's got a 4-port valve (valve and parts long since NLA) that reverses the flow when heating. In this mode, flow returns through the main drain, and is drawn from the skimmers and top-side returns. I've never done any good comparison of the heating results, though. It's been more of a labor of love to try to keep that system operating. Main problem is that the valve stem on the 4-port is non-standard; the actuator (a standard Jandy) has a modified shaft to fit the Urban valve stem. Very custom setup that apparently never caught on in the pool industry.

Anyway, given you're plumbed for it, it's much easier to deal with. I do suspect any comparisons you're able to do will not reveal a material difference, as Allen says.

 

[1poolman1]

Took me a while to figure out that my pool (built by previous owner) was fitted with the Mark Urban flow reversal system. It's got a 4-port valve (valve and parts long since NLA) that reverses the flow when heating. In this mode, flow returns through the main drain, and is drawn from the skimmers and top-side returns. I've never done any good comparison of the heating results, though. It's been more of a labor of love to try to keep that system operating. Main problem is that the valve stem on the 4-port is non-standard; the actuator (a standard Jandy) has a modified shaft to fit the Urban valve stem. Very custom setup that apparently never caught on in the pool industry.

Anyway, given you're plumbed for it, it's much easier to deal with. I do suspect any comparisons you're able to do will not reveal a material difference, as Allen says.

Only saw one of those installations at least 25 years ago. Took a class on how to install them but never sold one. Sounds great, in theory. The customer found it too much work to try to keep track of when to change valve position and said he never saw much difference in the way the water heated. He had both solar and a gas heater.

Its not the same as having true floor returns. You would be better off using the system as a "regular" pool and allow water to be drawn through the skimmer where there is a basket to help keep debris from clogging a suction line. If you have any kind of pool cleaner in the pool, not robotic, it will help with distributing warm water to the bottom (pressure-side cleaner, even not running) or pulling water from the bottom (suction-side cleaner) to mix with the water off the top at the skimmer.