"BigWallop" wrote in message
...
"Bob Mannix" wrote in message
...
"Wanderer" wrote in message
...
On Tue, 22 Jul 2003 13:42:09 +0100, Christian McArdle wrote:
snip
Another alternative is to stick a 3kW immersion heater in some
suitable
chamber and pump the water through. An immersion is dirt cheap and
I'm
sure
you can find some suitable "cylinder" to immerse it in, provided
suitable
safety precautions are taken. (I might consider a vent pipe straight
up
to a
metre or two above the pool level from the top of the chamber, for
example).
Hmm, pool heaters are essentially un-vented flow boilers (albeit with
an
excess pressure safety valve). It's the passage of water through the
boiler
that keeps it operating safely. They *must* be wired so that they only
work
when the filter pump is on. I think you'd need to get some sort of
cylinder
that was little bigger than the bore of the (usual) inch and half
diameter
pipework.
How about a combination:
PUMP
____
=========/ \==================================
=========\____/= ==================== =========
||
|| ||________||
| _________|
|| ___||___
|| | |
|| | |
|| | |
|| | |
|| | |
|| | ~~~~|
||______| |
| _______________|
Flow restrictor/isolator (valve)
~~~~ Immersion heater
with thermostat
in vented tank
The thermostat would prevent boiling in the normal way if
the pump failed.
The first flow restrictor could be set so the pressure in the tank
during
pump operation was not sufficient to blow water out the vent.
The whole heater section is an "add-on" that can be isolated for repair.
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)
Or how about a submersible heater like they put in fish tanks only on a
bigger scale.
But I really think this is the type of thing you should be looking to fit if
you're thinking of using your pool over winter.
http://www.exheat.com/prod.php?id=83
---
www.basecuritysystems.no-ip.com
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (
http://www.grisoft.com).
Version: 6.0.502 / Virus Database: 300 - Release Date: 18/07/03