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: UFH actuators to control water storage system?  (Read 6380 times)
Pilgrim
Newbie
*
Offline Offline

Posts: 20


« on: July 26, 2017, 11:00:26 AM »

I have a large tank in my loft. I'd like it to automatically drain if it gets too hot. I was wondering about using an UFH actuator to control the drainage. If the temperature was too hot, it would open and drain. Any views?
Logged
Sean
Hero Member
*****
Offline Offline

Posts: 641


« Reply #1 on: July 26, 2017, 11:29:37 AM »

Seems a shame to waste all of that energy.

I cant see the advantage of using an actuator, what's wrong with using a 2 port motorized valve and a pipe stat ?



Logged
Countrypaul
Hero Member
*****
Offline Offline

Posts: 1502


« Reply #2 on: July 26, 2017, 11:50:03 AM »

What is the tank used for and why do you feel you need to drain it when it gets too hot (and what is too hot)? It does sound like it will be a complete waste of energy at the least, but possibly more especially if it is mains water. Is the tank insulated properly?
Logged
Pilgrim
Newbie
*
Offline Offline

Posts: 20


« Reply #3 on: July 26, 2017, 11:55:02 AM »

As it's in the loft, I'll insulate it, but there needs to be a failsafe to prevent legionella if it gets above 20
Logged
Sean
Hero Member
*****
Offline Offline

Posts: 641


« Reply #4 on: July 26, 2017, 12:14:40 PM »

Have you ever measured the temp as being anywhere close to 20 ?
Logged
Pilgrim
Newbie
*
Offline Offline

Posts: 20


« Reply #5 on: July 26, 2017, 12:53:05 PM »

The current space, before being isolated from the rest of the building regularly hovers around 19 20 degrees.
Logged
TT
Full Member
***
Offline Offline

Posts: 227


« Reply #6 on: July 26, 2017, 01:00:47 PM »

Just make sure the tank is the right size for the premises.
Good turnover of cold and hot water and you will be fine.

No point in doing all that work if you aren't going to measure temps at sentinel taps, remove dead legs, c&d tanks, shower heads etc
Logged
Sean
Hero Member
*****
Offline Offline

Posts: 641


« Reply #7 on: July 26, 2017, 01:19:55 PM »

The current space, before being isolated from the rest of the building regularly hovers around 19 20 degrees.

I'm guessing that'll be ambient air temperature ?

If it's a large tank, and given a reasonable amount of turnover (use) it'll take a much higher ambient temp, and a fairly lengthy period of time for the tank contents to get to ambient.
Logged
Pilgrim
Newbie
*
Offline Offline

Posts: 20


« Reply #8 on: July 26, 2017, 02:39:45 PM »

Seems a shame to waste all of that energy.

I cant see the advantage of using an actuator, what's wrong with using a 2 port motorized valve and a pipe stat ?





Ah, so a 2 port motorized valve draws less electricity. I thought an actuator would be cheaper.
Logged
bxman
Hero Member
*****
Offline Offline

Posts: 646


« Reply #9 on: July 26, 2017, 02:50:47 PM »

This is rainwater for flushing loo and for  the washing machine. ?

I would just record the temp.

It would IMO be very unlikely to get that warm in this country.

If you were worried take the inflow to the bottom of the tank and any overflow would naturally discharge the warmer water from the top of the tank .
Logged
Pilgrim
Newbie
*
Offline Offline

Posts: 20


« Reply #10 on: July 26, 2017, 03:02:32 PM »

This is rainwater for flushing loo and for  the washing machine. ?

I would just record the temp.

It would IMO be very unlikely to get that warm in this country.

If you were worried take the inflow to the bottom of the tank and any overflow would naturally discharge the warmer water from the top of the tank .

My initial plan was to just record the temperature, but I thought that might not be sufficient for the authorities.

Great idea about taking the fresh water to the bottom BTW!
Logged
Pilgrim
Newbie
*
Offline Offline

Posts: 20


« Reply #11 on: July 27, 2017, 07:16:22 AM »

Does anybody know a simple way to control a motorised valve to drain if the water reaches 20? Ideally I would like to control this with another valve that fills the tank from the mains if the level is too low, but not if the water is being emptied.
Logged
Countrypaul
Hero Member
*****
Offline Offline

Posts: 1502


« Reply #12 on: July 27, 2017, 08:42:15 AM »

You could use one valve to open at 20C and drain the tank, whilst having another that stops the filling at say 15C.

Filling to the bottom of the tank from mains water needs to be setup so that water cannot be sucked back into the mains pipe which normally means an air gap using a ball valve (check the regs).
Logged
Antman
Global Moderator
Hero Member
*****
Offline Offline

Posts: 1962


WWW
« Reply #13 on: July 27, 2017, 09:08:33 AM »

Probably worth pointing out that motorised valves intended for heating systems are not designed to be used as flow control on open systems i.e. they should not be used as a tap (shut-off valve). They are designed for closed-loop systems where there is a balanced static pressure on both sides.
To put another way, they are likely to 'let-by' if you try to hold back a head of water to open drain.

I would have thought good insulation around the tank will keep it below 20 especially if the water is being used. We don't worry about mains filled tanks getting too hot do we? And the incoming water fill temp is probably similar over summer.
Regards
Antman
Logged

20 x 47mm, 172 l cylinder, Heat Dump, 15 x Sanyo HIT-H250E, SB4000TL,  Nestor Martin IQ13 WBS
DIY Solar System Support at http://www.handyantman.co.uk/antman.html
All support is voluntary and free of charge. I'm not employed by Navitron so responses may not be same-day
TT
Full Member
***
Offline Offline

Posts: 227


« Reply #14 on: July 27, 2017, 01:55:55 PM »

Not that I agree about this scope of works being necessary, but what about a solenoid valve as used in washing machines etc.

Logged
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!