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rustyrod
Senior Member
Joined: 08/11/2014
Location: AustraliaPosts: 121 |
| Posted: 02:44pm 10 Nov 2014 |
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In HOT water or maybe not?
A year ago, I was in town supporting the medical profession when I got a phone call from a sleepy son “There had been an explosion that shook the house and he wondered if I knew what it was?”
I suggested he get up and take a look around.
Three quarters of an hour later another call, Very much awake and Frantic “The back room is flooded with hot water and it was still coming from the cupboard”
Luckily? We had run out of tank water and were back on the town mains, so it should be as simple as going to the footpath and turning off the mains.
Simple I say, compared to crawling under the house and getting to the pressure pump and the taps way under there with cobwebs and all.
Arriving home hours later, the back room is flooded 25 mm deep and water still coming from the cupboard which is raised 75 mm from the floor.
The water main was dug up with a------? Sledge Hammer?---- and not turned off.
Using the handle leaning against the fence, I turned the water off. Duh.
Returning to the house I could hear water running into the gutter????
I have three hot water systems.
A solar unit on the roof (summer) connected parallel with the night rate electric unit (winter) in the cupboard and a small 30 litre unit fed from these over at the ensuite.
The mains pressure here varies from 980 kpa to 1200kpa. I am last at the end of a street and bottom of a mountain.
All units are fitted with 1400 kpa (200psi) hot safety valves to stop the hot water discharging under the house.
Investigating, I found the solar unit had one end convex instead of concave and water was dribbling from one solar panel and the hot water system in the cupboard had it’s bottom turned inside out and blown/split as well!!!!! (See near yellow tape)
Solar Unit and the Bottom of Electric unit
The females were most concerned about the events and how were they to showed/bath and do washing if there was no water anymore?
Did I mention I am a hoarder/collector? I had more water in my eyes than on the floor looking at all the boxes of unopened things and boxes of books ect slowly soaking up the warm water.
At the precise time the council was working on the mains further up the street.
Contacting the council they say “it is my responsibility to fit a water pressure regulator on my side of the water meter” “Thanks for calling”
I shifted all my “stuff” to other rooms and some out side to drip dry, then rolled up the vinyl.
The insurance company dried the particle board floor with a big heated jumping castle mat, 45 units of power and 3 days later they were going to cut out the now dried floor part and replace that section. (The floor is more damaged over by the doors from rain blowing under. NO, They will not do that.)
BUT
The insurance plumber said some mandatory restrictor valve was not installed near the hot water system
“Good bye” No charge. No Excess. No new floor. AND definitely No hot water systems.
Now my first quandary, where did this massive pressure come from?
The night rate power was off - so not from there.
The sun was shining, it was 11 am ish, would not be too hot yet and the solar had been up for 3 or 4 years and no problems - so maybe not there?
I suggest “water hammer” which no one will confirm.
I cannot afford to get a new solar and electric system and anyway I refuse to buy some.
I relocated the little 30 litre unit into the repaired cupboard; wired the power to the “oven” circuit and we were back in water.
I sounded out any leads to old units stashed in back sheds and checked regularly at the scrappies, after some months I got a copper tank with coils in it.
I t was heavy and rattled. I cut the top out and found 4 buckets of sediment which I had paid copper price for. I took the sediment back for a refund. Vacant looks and head shaking.
The copper tank leaked, the coils I put it away for later on.
9 months later led me to a back shed and a complete old REGAL type with the copper coils inside. FREE. I whipped that out of there so fast the dust and spiders were left behind.
Water in, Water fill, Hot out, Overflow, Vent.
(this one sold on gumtree for $74 about half what I paid for the scrap dud tank)
I dismantled the unit by cutting the rusted bottom out of the tin outer cover thus letting all the foam balls over the yard and removed the inner copper tank. Tested it for leaks.
I then unsoldered the ½ inch drain and replaced that with a 1 inch copper pipe. I silver soldered another 1 inch pipe on the other side about 2/3 of the way up, then soldered elbows to all the piping at the top going into the unit and fitted ½ inch copper piping down the side past the bottom, dismantled and silver soldered the 75 mm split in one solar panel tube.
I made up a stand to suit the slope of the roof.
My wife and I skinned the electric hot water system that blew up.
I assembled the copper tank back into the outer cover, stuffing it with pink batts then fitted the skin from the old unit over the outside covering all the pipes, stuffing that with another layer of pink batts.
This makes a nice tidy looking unit up on the roof.
Connected up the panels, run it full of water, tightened a few drips and waited for the sun to do its thing.
The 1 inch circulation pipes are wrapped in layers of fibre glass matting, taped and covered with 2 inch pvc or poly pipe.
Looking Hot
A Rheem skin with a Regal tucked inside
WOW at 7pm a scalding shower and not a cent spent on electricity to heat the water.
I am so good. I will add radiator anti freeze before winter and so will not need power for anti ice. I stand in the back yard with a smug smile and shine a torch on my creation. Just needs a coat of paint.
10 pm a shriek from the bathroom “There is no hot water, It is freezing”
What went wrong where did the hot water go? Back on the roof and sure enough everything is dead cold. Where did I go wrong? Pride comes before a fall, ringing in my ears.
So onto the internet and learn the bottom of my tank should have been 300mm or more above the solar panel, to stop recirculation. I am not making more stands and beside it would need more 1 inch copper pipe, joiners, soldering and look ugly sticking up above the roof.
Next morning back to the roof, let the water go, I fitted a flappy one way valve in the bottom pipe by cutting a brass union in half, silver soldering each half to the cut pipe and screwed in the valve and waited.
1 pm and the water is boiling and crackling in the solar panels but the bottom pipe is cold.
My conclusion the circulation cannot open the non return valve. Let the water go again.
Pulling it to pieces I observed that the flap is attached by an offset type of hinge. I can hardly blow through it.
Experimenting with tilting it on an angle, I could get the flap weight neutralized.
I bent the pipes and refitted the valve.
Next day, Success, Scalding water by 3 pm and still quite hot at 10pm.
BUT next morning WHERE HAS THE “HOT” GONE ? It is only luke warm!
Only three showers the night before. (By the way, Same night after night)
Next night, 8pm, back on the roof. The storage tank near the electric element fitting, is very hot to the fingers, The pipe is hot between the storage unit and the flappy valve and cool on the down side. The top (hot) pipe is so hot I can’t hold my hand on it and the top outlet of the solar panel is cool, the bottom inlet of the panel is cold.
I assume from this there is no recirculation.
My tank is doubled insulated compared to any other system.
This the bottom end. The RED handle is the cold water inlet to the coil.
The chrome tap fills the tank. The ½ inch copper pipe union is the hot water delivery down to the house. The older brass tap is a drain, if I need it.
The over flow and vent are inside.
Inside the blue tape is the flappy one way valve tilted at an angle.
The band across the access cut out is the raised side of the old system top fitted as a collector tray to catch any leaks and run them off the roof over the back door (so I notice) and also stop any antifreeze ending up in my tanks. No precautions have been taken against a panel leak, however as there can never be any pressure in them I hope/pray I don’t get a leak.
I have left the electric element in to block the hole and maybe for a dump load.
I guessing the tank is about 100 liters capacity.
I am perplexed?
Would an electric unit up on the roof exposed to the night loose it’s heat as rapidly without the power turned on?
Lessons learnt –
I know that the panels will cool the storage water exceptionally faster than the sun can possibly heat it up.
Open up any copper tanks at the scrappy and tip out the sediment before weighing.
I got away with it, but test your creation for leaks before putting it all together. The filler pipe elbow leaks only when the tank is filling/topping up.
Any suggestions?
Always Thinking |
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norcold
Guru
Joined: 06/02/2011
Location: AustraliaPosts: 670 |
| Posted: 09:29pm 10 Nov 2014 |
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Your definitely in hot water and will go deeper if the treasurer puts up with another cold shower. Anyhow welcome, sounds like a trying time, one of those Murphy sends to try us now and again.
We come from the land downunder.
Vic |
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VK4AYQ
Guru
Joined: 02/12/2009
Location: AustraliaPosts: 2539 |
| Posted: 11:36pm 10 Nov 2014 |
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Hi Rusty
Mount your tank on the ground and fit a small solar circulation pump to pump through the panels during sunlight run it off a small solar panel or whatever you have, you can also get 240 volt ones, it keeps the tank where you can work on it and you can make a convection trap so it stays warm overnight, no stress on the roof and no ladder stress for you.
All the best
Bob
Foolin Around |
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Tinker
Guru
Joined: 07/11/2007
Location: AustraliaPosts: 1904 |
| Posted: 12:37am 11 Nov 2014 |
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Rusty, I would second Bob's suggestion.
That top heavy water tank on the roof looks like a disaster waiting to happen the first time strong winds discover it. I would think your tank stand is not up to the job, if you leave the tank up there do fit at least 3 guy wires to the top of the tank.
Klaus |
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govertical
Guru
Joined: 11/12/2008
Location: United StatesPosts: 383 |
| Posted: 05:52am 11 Nov 2014 |
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http://youtu.be/m82CnWGuZZA
Hi, did a quick experiment with a J tube rocket stove. I was hoping for a system meltdown. It never happened. The non-insulated pipes dissipated the heat real fast. It may give you some ideas. I will have to try adding a small circulation pump and more insulation. Thanks for posting.
just because your a GURU or forum administer does not mean your always correct :) |
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rustyrod
Senior Member
Joined: 08/11/2014
Location: AustraliaPosts: 121 |
| Posted: 02:25pm 12 Nov 2014 |
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Thanks one and all,
My creation has been up for a couple of months by now and a pattern is emerging.
Wallaback has given me a clue
“Solar hot water is an option I am investigating. We have 4 kids, 3 of them girls who like long showers. Currently we have a 2yr old 350L electric hot water and some days we have run out before the end of the day”
And one night recently, I was up in the early hours with gastric when the son and his girl came home.
I noticed the pressure pump running and running. They “need” a long shower to relax them before going to bed. What do young people do when “chillin” in town that stresses them?
I seem to remember when the old unit that was in the cupboard (260 l on night rate) occasionally, I would come home in the evening have a break and go for a shower and no hot water, they had used it all before going out.
Why is it that when you put your hand under the shower, if you are clothed the water is cold but if you are naked it is FREEZING?
Initially I had the thermo on the electric unit, set low thinking I was saving power but as not much cold was added the hot soon went.
I cranked the thermo up and with cold now having to be used the actual hot lasted much longer.
You would think someone in the house could have mentioned these long showers especially the midnight/early hours thing. Maybe I need a “stress” shower.
I had noticed the pattern that when the kids were not here there was still hot water in the morning. I am slow.
My tank is only 100 litres. I am thinking this is only good for 2 or 3 quick shower people.
Winter and cloudy days are going to be interesting.
I believe on solar we need bigger reserves of lower temp water compared to the high temps electric units maintain.
I bought one of those point and press the button temp things.
[I'm having trouble here the cut and paste then preview takes out all the "spaces" therefore cramping my graph]
Averages when not all used up. degrees in Celsius
-----------Morning----10am-----3pm-----10pm---hottest observed
Tank near
Element.......36...........40.......55........50...........7 0
In hot........38...........42.......65........55...........75
Pipe
Top outlet....40...........50.......72........30...........98
of panel
bottom........30...........37.......50........25...........7 0
into panel
norcold thanks, Murphy is everyone’s best friend
VK4AYO I had thought of the tank in the cupboard and the pump BUT
as the tank is vented I was concerned if a panel leaked, the water would drain back and “flood” then how to prime the panels without air locks.
I could have connected a header tank to the vent and put that above the panels.
more leaks/too lazy.
tinker
THANKS, It never occurred the thought of the wind, guy wires will be going on soon.
I have now looked at all my panels sticking up like wings ready to lift off.
Panels face north here and most bad storms come from south west, definitely a disaster waiting.
This unit is smaller than the old one so less weight. There are heavy rafters and batons for the purpose.
govertical well it was worth a try
Watch this space! Murphy and I are working on a solution to the lack of volume with a pressurized 160 litre unit in the cupboard and another set of panels with a 20 watt solar cell and pump. Lots of valves and fittings, should be fun.
I am thinking that the 100 litre will pre heat the water for the 160 l unit and the pump/panels will keep it hot.
This will get me back to the 260 litres where I started.
I am just waiting for a satellite with a hook on it to pass slowly over the house so I can winch the panels up.
Then I suppose should put the 30 litre back on the en-suite. Maybe?
This story should be a BLOG what ever that is.
Always Thinking |
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norcold
Guru
Joined: 06/02/2011
Location: AustraliaPosts: 670 |
| Posted: 03:58pm 12 Nov 2014 |
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Never mind a blog (whatever that is) sounds like the theme for a brilliant video, not sure it`d be wise to act with Murphy in the same video but! You know never act with kids and animals, sort of thingo. 3 daughters????, I had only one and went grey at 28.
We come from the land downunder.
Vic |
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rustyrod
Senior Member
Joined: 08/11/2014
Location: AustraliaPosts: 121 |
| Posted: 06:54pm 24 Feb 2015 |
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Marcia is coming, Marcia is coming,
So you all know where I was;-
Up on the roof, finishing welding the mounts and adding extra screws to hold everything down.
I even put on the guy wires. Thanks Tinker
The sky hook came at Christmas time in the form of my youngest son and a few of his mates to lift the panels and the newly made stand up to the roof.
I have waited for cloudy days to squeeze into the ceiling to lay in the pipes.
The space is so small I have to lie on my back and wriggle on the insulation then by reaching over my head and twisting my neck around I could get the pipes and wires into where I wanted them, all the time hoping the plaster ceiling doesn’t let go.
Taking the roof sheeting up wasn’t an option as the joints are stuck with glue gunk.
I have covered these pipes with the green insulation sleeving. I am not too impressed with this sleeving as it is very warm on the outside when hot water is flowing in the pipes.
I think I will add the thicker black sleeve over the top.
Picture description. From the Top.
Digital Temp readouts of the First system on the roof.
12 volt solar controller.
Left switch to frost heater in panels, Right switch to System Element (Night rate power)
Display
Hot water controller
Single switch for pressure pump under the house
Left Vertical tap is town water entry, then Pressure Regulator. Battery. Vertical tap is pressure pump entry. Next vertical tap is for when I get a high tank.
Down beside the system is the pump and valves.
The 120 liter hot water unit is fitted up in the cupboard where the big one was when it blew up.
I have a controller and the 15 watt recirculation pump with and old battery from my electric scooter and 2 by 20 watt solar panels.
When the hot water panels are 6 degrees hotter than the system the pump starts the circulation.
The pump runs for a while then shuts off again. This cycling continues on and off during the day until about 3 pm at this time of the year.
How it all comes together
The supply water now goes up to the first system and is pre heated then back down to the second system where it is heated some more.
Pre heated water enters via the chrome tap and into the system through a ½ inch pipe inside the ¾ inch tee, up into inside the tank 300 mm
The pump draws from the bottom of the system via the ¾ inch tee through a ball valve and a non return valve.
On right is the cold water inlet pressure safety valve ( The piece that was not there before – so no insurance)
The hot water from the panels returns to the system through this dual pressure/temperature safety valve.
The outlet (on left) connects the original house hot water plumbing.
I put this together in this complicated way instead of simple tees as I was concerned that if the pump was running and some one went for a shower, the cold water would be pumped through the panel faster than the draw off from the system resulting in “cold water”
In fact the controller would sense the cold water at the panel and shut the pump down.
I am hoping in winter the restrictions of the one way valve and the pump will prevent the cold water by passing the system. Time will tell.
I have recycled all old fittings I had on hand.
Summaries.
Over time I have learnt the best the first one can heat to is around 60C and about 30C on cloudy days with cold during rain.
I also believe it continues to thermosyphon late into the evening.
The hot water inlet from the solar panel is 1/3 of the way down the side of the re-circulation tank so even if the water above this point is quite hot the thermosyphon works below this and as the water in the lower part of the panel cools it pulls warm water out of the bottom of the tank which then warms up slightly, but enough to circulate and slowly cools the whole system until dark when the panel is all cold enough to stop.
If, I were to make another or had the inclination to alter this one I would –
Put the hot re-circulation inlet pipe close to the top,
Mount the whole tank so as the bottom is 300mm or more above the top of the panels.
The unit in the cupboard has gotten to 90 C and averages around 80 C
During some rain lately it was still in the 50s C
It has been altogether for a month.
How will it perform over winter?
The first unit has antifreeze in the tank and the second unit’s panels have a thermostat controlled 30watt 240volt element connected to the night rate, to stop them freezing.
I realized now the second units panels are made of steel not copper so I expect they will bust one day and I can do it all over again.
Costing;- around $350 in all.
My power bill has dropped the hot water night rate from around $200 to just 1 unit.
So I will cut it out in just TWO bills.
Conclusions.
The first unit needs some refinements.
The second unit is quite successful.
Now I need to put a small unit back on the ensuite with both night rate grid power and the 24 volt dump element and I will be “In hot water”
Watch this space ( )
Always Thinking |
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gww1
Regular Member
Joined: 14/06/2013
Location: United StatesPosts: 63 |
| Posted: 04:21am 25 Feb 2015 |
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Very nice
gww |
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MadRat
Newbie
Joined: 30/09/2008
Location: United StatesPosts: 21 |
| Posted: 05:03pm 09 Mar 2015 |
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If you ever reroof then next time integrate the panels into the roof. Your loading with metal roofs typically is much lower than shingles where you can lay down a layer of foam sheets, a new deck over the top, and a new metal skin without getting too heavy. It all depends what was underneath.
But integrated panels will help to mitigate those wind factors. And if you build it right you can do maintenance on the darn thing without ever going back into the tight attic.
Go Huskers! |
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rustyrod
Senior Member
Joined: 08/11/2014
Location: AustraliaPosts: 121 |
| Posted: 12:32am 23 Mar 2015 |
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"I realized now the second units panels are made of steel not copper so I expect they will bust one day and I can do it all over again"
How I wish I had never said that. 
I jinxed it!
One panel sprung a big leak over the weekend 
So I am back to the Regal conversion I made until I get time to open up this panel for a looksee.
I suspect the plumbers damaged the internals when removing the panels as I had extreme difficulty undoing the cut off damaged pipes as I set it up.
As a point of interest the remaining water in the panels was crackling and blowing steam today.
I will drain them and cover them in the morning.
Always Thinking |
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Downwind
Guru
Joined: 09/09/2009
Location: AustraliaPosts: 2333 |
| Posted: 02:31am 23 Mar 2015 |
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I have some trouble with your panels returning the heated water to the top of the tank, it should return about 2/3 down the tank so the heated water rises in the tank.
Your stored volume of hot water will increase greatly this way.
Been there and done what you are doing.
Pete.
Sometimes it just works |
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rustyrod
Senior Member
Joined: 08/11/2014
Location: AustraliaPosts: 121 |
| Posted: 12:39am 19 Dec 2015 |
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I simply had to put this photo up
Is this cucumber going to be in hot water or just a pickle? 
Always Thinking |
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Oscar4u
Regular Member
Joined: 23/02/2011
Location: New ZealandPosts: 42 |
| Posted: 07:40pm 20 Dec 2015 |
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Hello Rusty rod
We have a solar panel here on the house and one on the sleep out. Both I worked it so that the cylinder is higher than the panel and thermo syphon the hot water. This way it is not possible for hot water to cool overnight. Both cylinders are vented to atmosphere so there is no chance for a valve to fail or water hammer problems. No electronics or pumps to worry about and it will even work in a power cut! There is a neva pressure reduction valve on each and that is the only thing that can break down. In the house I mounted the cylinder and the neva valve above a stainless shower tray with a 38mm pvc waste pipe going through the wall outside so that any leaks will not flood the house. We have minor frosts here but because the water is all low pressure the chance of frost damage is low. A plumber once told me if there is a foot of high pressure water line outside and ten meters of low pressure, the foot of high pressure pipe will burst first. I run town water drinking water through the whole system and it works a treat. Also have a wet back on both cylinders. If I were to do it again I would not change a thing. Kiss! Also solar tubes are highly recommended. If you get the right once they do not have water in them and can not freeze. Cheers
Oscar
Oscar4u - for all your rotary cowshed repairs |
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