navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address - following recent spam/hack attempts on the forum, all security is set to "high", and "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1] 2   Go Down
  Print  
Author Topic: Hot water cylinder temperature gauge  (Read 5264 times)
woodstove
Newbie
*
Offline Offline

Posts: 25


« on: March 15, 2017, 06:18:08 PM »

Can someone please suggest a suitable solution to this problem.

Now it's getting a bit warmer, our boiler wood stove is not needed until the evening. It supplies all our hot water and I get asked nearly every evening if there is enough hot water for a shower or bath etc.

So, I would like to fit a suitable gauge to the hot water cylinder that anyone in the family can view and determine how much hot water is available.

Thanks for reading.

Logged
eabadger
Hero Member
*****
Offline Offline

Posts: 895


« Reply #1 on: March 15, 2017, 06:29:20 PM »

bottom two show temp at bottom and top of cylinder
rest show wood boiler temp up pipe temt and ufh temp and rad flow return temps.


* IMG_0480.JPG (552.17 KB, 1632x1224 - viewed 1243 times.)
Logged

1600w PV main array at 24v, excide 2v 1000a forklift cells now x 2, 320w PV secondary array at 12v. Enfield 1944 ex RAF 5.6kw diesel genset (now in pieces, big ends gone), Petter AC1 28v diesel charging set at 2.8kw.
1kw wind turbine.
26kw wood stove back boiler to underfloor heating and dhw
woodstove
Newbie
*
Offline Offline

Posts: 25


« Reply #2 on: March 15, 2017, 07:01:38 PM »

Thanks for your reply ...... I'd actually been looking at your system already, very nice.

Have considered building a copy of yours, but was holding off hoping for a simple 'off the shelf' solution...... but so far haven't found anything, so I started this thread.

It's hard to believe that there's still no simple way to read the amount of hot water that's stored in a simple hot water cylinder?


Logged
AndrewE
Sr. Member
****
Offline Offline

Posts: 338


« Reply #3 on: March 15, 2017, 07:09:35 PM »

I have a (lower) solar thermal coil in our cylinder and an upper coil fed from the gas boiler...  a hand on the house outlet flow pipe then on the (boiler) coil connectors tells you quickly how much hot water is available.  However by evening (or earlier if it's one of our regular "going out" evenings) the old gas boiler will have topped up the temperature in the top half if it thought it was necessary.  The only problem is if you want a bath mid-afternoon in the winter before the gas water heating has cut in, when you have to switch it on and wait a while...
Logged
woodstove
Newbie
*
Offline Offline

Posts: 25


« Reply #4 on: March 15, 2017, 07:34:05 PM »

Thanks Andrew ........ I have used the hand on pipe method, and but then a little while later I'm told the shower went cold or there wasn't enough water to fill the bath  hysteria





Logged
eabadger
Hero Member
*****
Offline Offline

Posts: 895


« Reply #5 on: March 15, 2017, 08:22:52 PM »

i think they were 3 each and then the box to mount them on.
off the shelf can be making do as not all have same set up.
i am adding to mine now i have seen it woprks well, i use the outputs to bring on floor or rads as required.
Logged

1600w PV main array at 24v, excide 2v 1000a forklift cells now x 2, 320w PV secondary array at 12v. Enfield 1944 ex RAF 5.6kw diesel genset (now in pieces, big ends gone), Petter AC1 28v diesel charging set at 2.8kw.
1kw wind turbine.
26kw wood stove back boiler to underfloor heating and dhw
marcus
Sr. Member
****
Offline Offline

Posts: 370


« Reply #6 on: March 15, 2017, 09:08:53 PM »

I have a single temp probe near the top of my small hot water tank; over time I've learned to interpret it's readings in combination with how the tank was heated:-

if using the Woodburning stove (normal winter), the coil on the bottom of the tank heats all the top evenly so any temp over 43C is enough for a warm bath; 48C for a hot bath.
if using the immersion slowly over the day (normal summer - dumping excess power into the top-down immersion), anything over 44C is OK for a modest warm bath. 48C for a hot bath. 52C for a generous hot bath.
if using the immersion on grid (a few minutes at a full 3kw input - I hardly ever do this), 55C will give a meagre hot bath or a modest warm bath but you must remember to turn off the water before it goes stone cold.
Logged
woodstove
Newbie
*
Offline Offline

Posts: 25


« Reply #7 on: March 15, 2017, 10:05:41 PM »

Thanks again ebadger ..... 3 is not a lot!, do you think they'll last?

Thanks Marcus ......... that's roughly how I see it working for us.

Just want something to indicate there's enough hot water, then simply check it again after each use.
What type of temperature sensor are you using?
Logged
eabadger
Hero Member
*****
Offline Offline

Posts: 895


« Reply #8 on: March 16, 2017, 08:25:58 AM »

will they last at 3? anyones guess but they look ok, i ordered double in case of issues.
250ltr main pressurized cylinder twin coil, lower main coil on the big wood boiler, top is a little 5kw oil boiler.
two temp pockets on the cylinder, on wood i aim at 60* + at top.
family like the display idea, they dont have to ask about showers now, but the two eldest hammer the 250ltr.

you could always use a infrared thermometer point at place on cylinder and read external temp, any sensor pockets?

steve
Logged

1600w PV main array at 24v, excide 2v 1000a forklift cells now x 2, 320w PV secondary array at 12v. Enfield 1944 ex RAF 5.6kw diesel genset (now in pieces, big ends gone), Petter AC1 28v diesel charging set at 2.8kw.
1kw wind turbine.
26kw wood stove back boiler to underfloor heating and dhw
mr_magicfingers
Hero Member
*****
Offline Offline

Posts: 847



« Reply #9 on: March 16, 2017, 10:03:06 AM »

I have a similar system to eabadger, cheap 1.99 thermometers from eblag. I have the sensors in pockets that were put in when the cylinder was ordered - top, middle and bottom, plus two extra for the flow and return pipes from the woodburner. I used a piece of cat5 cable to extend the sensor wires and they're mounted in a plastic box that's in the room near to the woodburner. A quick glance tells me how much hot water is in the tank and whether I need to light the fire or give the immersion an hour's boost. Also tells me how much heat the pv diverter has been throwing into the tank on a sunny day.

Cost under 15 and a couple of hours of my time.
Logged

Solar PV: 6kw (24 x REC 250w), Sunny Boy 3600TL-21, roof facing 178 at 40 slope.
300l Thermal Store, 2 x 3kw immersions via Immersun + Dunsley Yorkshire WBS
Woodwarm Double sided 6kw WBS
7 acres of old woodland I'm slowly bringing back into order.
marcus
Sr. Member
****
Offline Offline

Posts: 370


« Reply #10 on: March 16, 2017, 09:49:45 PM »

I don't actually know what my temp sensor is - well, it's a newport digital pyrometer with GPIB/IEEE488 interface IIRC - i fished it out of the rubbish skip at the place I used to work many years ago and it was probably dreadfully expensive when it was new. If I were looking to buy one now I'd go for one of those cheap n cheerful chinese ones for something like this.
Logged
Zaph
Newbie
*
Offline Offline

Posts: 6



WWW
« Reply #11 on: August 17, 2017, 11:28:59 AM »

Hi
Badger, any clue where we can get some of those cheap thermometers pictured? More importantly, how long can you make the lead?
Logged

10KW back boiler, old house, small scale solar heating. Rudimentary.
mr_magicfingers
Hero Member
*****
Offline Offline

Posts: 847



« Reply #12 on: August 17, 2017, 01:20:48 PM »

Hi
Badger, any clue where we can get some of those cheap thermometers pictured? More importantly, how long can you make the lead?

Not badger but mine are from ebay, similar to this, https://www.ebay.co.uk/p/Digital-Aquarium-Reptile-Thermometer-With-Probe-Freeze-UK-SELLER/1688591981?iid=111418097114

I cut the wire and extended with cat 5 cable in between, I have extended them about 5-6m.

Hope that helps.
Logged

Solar PV: 6kw (24 x REC 250w), Sunny Boy 3600TL-21, roof facing 178 at 40 slope.
300l Thermal Store, 2 x 3kw immersions via Immersun + Dunsley Yorkshire WBS
Woodwarm Double sided 6kw WBS
7 acres of old woodland I'm slowly bringing back into order.
Zaph
Newbie
*
Offline Offline

Posts: 6



WWW
« Reply #13 on: August 17, 2017, 02:45:04 PM »

Ah, OK thanks. These definitely appear to use the DS18B20 waterproofed 1-wire digital sensors, so yep should work up to 40 meters.
Added one to my weekend shopping list to try out. Still trying to work out where I want to mount the display. The basics will be to display the bottom of tank temperature, on the bathroom door I guess.
Logged

10KW back boiler, old house, small scale solar heating. Rudimentary.
Fionn
Hero Member
*****
Offline Offline

Posts: 537


« Reply #14 on: August 17, 2017, 03:07:18 PM »

If you only have one sensor I think a mid tank measurement would be more useful, but for the cost I can't think of any reason not to have one at the top, middle and bottom!
Logged

6.75kW PV - 2.75kW East, 1.5kW South, 2.5kW West. 3 x Flat Plate Solar Thermal with side arm FPHE on 268L cylinder
Pages: [1] 2   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!