Swimmig pool probs

[outinthestix]

Hi everyone, i'll keep this as breif as possible.
Can i use a pipe stat instead of a cylinder stat in a mid position valve system ?
I ask because i am going to service a boiler which heats a swimming pool and rads in the pool room. This is as well as serving the house heating and hot water on a separate piped system. The problem is the pool temp. is monitored by a two wire room stat which has been positioned close to the water pipes and so has to be turned up to max constantly and also is not capable of giving a HW off signal to the valve.It also does not switch the pump on (only the boiler), so the other room stat for the pool room heating also has to be on max to ensure that the pump is always running.
Can i get a pipe stat with a three wire connection and does anyone think it will cure the problems ? I am thinking of fitting it on the return pipe to the boiler from the pool water heat exchanger.Valve and prog. are both Landis & Steafa.
Any other suggestions greatly appreciated.
Thanks, Stix.

 

[Agile]

It will not work!

The pool heat exchangers are highly inefficient and run with a flow/return temp of say 70/60 whilst the pool water is say 22.3/22.1 The return primary temperature bears no relationship to the pool temperature.

You must use a proper digital pool stat which responds to the first decimal point.

It also sounds as if you need a seperate motor valve and stat for the pool rads.

Tony Glazier

 

[outinthestix]

Thanks for your input Agile.
Am i right in thinking then that the system is better served with two 2 port valves instead of the current 3 port ?
Also i am not familiar with pool stats. Presume they are wall mounted with a sensor in the water, is that correct ? Can you suggest a good one ?
Stix.

 

[Agile]

You need to visit a pool shop in person or online. The sensor is usually placed in the outlet from the HE as thats always in the flow because the pool pump operates all the time to filter the water.

I cannot comment on the valve arrangement but I dont see why a mid position would not do the job.

Are you sure there is no hot water for showers at the pool?

Tony

 

[outinthestix]

No showers. The pool is at a private house and mainly used by the owner and his wife.
I'll do a google on pool stats.
Many thanks, Stix.

 

[oilman]

It will not work!

Agreed

The pool heat exchangers are highly inefficient and run with a flow/return temp of say 70/60 whilst the pool water is say 22.3/22.1 The return primary temperature bears no relationship to the pool temperature.

This does not mean they are in efficient, they are heat transfer devices, and with this temperature difference, they work unless they are scaled up.

 

[doitall]

Quite the opposite Tony, Pool heat exchangers are very efficient.

The pool water should be set in relation too the air temperature unless you want too rot the building out with condensation

 

[Agile]

Pool heat exchangers are 100% energy efficient!

Pool heat exchangers are NOT efficient at transfering heat. So much so that the average pool HEs will not work well because the power transferred at a flow of 70°C on a unit rated at say 30 kW is more like 15kW in practice when the pool is at 28°C.

I doubt that many of you spend much time playing with boilers and pools etc. but the actual performance compared with the performance that I expect is rather poor according to the tests that I have done at several sites.

Tony