New hot water system ideas

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Re: New hot water system ideas

Postby Tracker » Mon Aug 25, 2014 10:31 am

davidg wrote:Pipe inside a pipe. Some tanks have 2 inlets so it's not required then. :D

slightly OT.. but when I think of most tanks I have encountered, they have a plastic tube inserted into the COLD entry, that sends the entering cold to the bottom of the tank..
do you know just how the tubeINtube works??
You would normally want to send the returning HOT upwards, and suck the cold from the bottom..

I could only imagine that the device protrudes WELL into the tank , so as to ensure that you are sucking the cold, away from where the hot is returning..
and... with tanks that I have played with, it is very hard to remove the factory-fitted plastic tube.. :(

I don't have a roof cavity so I'm not sure if solar is possible?

as per the last comment - we really don't have much to go on and so this is ALL pretty general..

Depending on what you mean by no-roof-cavity, SOLAR pipes could easily run above the roof..
returning to your main interest - INSTANT - do remember that there are INSTANT heaters that they install under the sink.. and plug into standard 10A circuits.. OBVIOUSLY, you will not get boiling water from that.. 2400W of power is about that of an electric jug.. you would end up with a low flow of warm water.. IMHO..
Assuming the power was available, you could think outside the box and cascade them (Possibly) to give a higher temperature..

You will likely see unapproved ones on EBAY and legal ones at BUNNINGS, and otherwise trade plumbing supplies..
GOOGLE should find some local products, and they would have to give details of performance..

PS - the thought comes to mind that IF you are creative, you could think about the tubular-heaters used in Front-Loader washing machines... ;)
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Re: New hot water system ideas

Postby davidg » Mon Aug 25, 2014 6:16 pm

Tracker wrote:I could only imagine that the device protrudes WELL into the tank , so as to ensure that you are sucking the cold, away from where the hot is returning..

Yes precisely, they actually work very well, much better than one would think. 8-) The yscreew directly in to the tank at the bottom since there all brass it's really not hard to do.
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Re: New hot water system ideas

Postby Boccas » Tue Sep 16, 2014 8:23 pm

I opted for a replacement 315lt stainless steel electric HWS. Then I upgraded from a 2kw solar system to a 5KW Inverter with 7kw of panels. Then installed a changeover switch. With the switch on 1 it connects to T11 standard tariff and on 2 it connects to T31 night rate. I am retired, so I switch it on 1 anytime between 10 am and 2 pm daily. It takes about 1.5 hours to reheat, nearly always free if the sun is out. On overcast days I switch it to 2 and it begins reheating from 10.30pm until the thermostat stops it in about 1.5 hours. Now one important reason I kept the 315lt HWS was that we lost 4 days of electricity supply when Cyclone Yasi hit, but even after 4 days we still had hot water available for showers.

This could also be done with Timers and Contactors to automate the daytime switching but nothing beats the manual changeover switch for ultimate control.
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