Nickfromwales Posted March 31, 2018 Share Posted March 31, 2018 That's my boy. . Ill add more in a bit ? 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted March 31, 2018 Share Posted March 31, 2018 (edited) Big ASHP, 4-500 lt storage and E7 running for a few hours before the alarms go off. You could add some inline heaters as a backup. You could also limit the flow rate to 8lt/min. I would be tempted to split the DHW and the space heating. Did I miss that you do/don't have gas. If gas, scratch the ASHP but still maybe use E7/E10. Or put in coin meters. I have just had my second bath of the day (my body aches dreadful sometimes). Did that on a gnats under 19 kWh for the whole house. The two storage heater and the water took a mean of 2.4 kW with a peak of 7.55 kW. Should be able to double that on a normal 100A supply and have a bit to spare. I also run the water up to 50°C, so you can get a bit more storage running it up to 65°C. It used to take my old lodger, before I beat her into submission (and showed her the £2000 water bill for the year) about 35 minutes to empty the cylinder. Shower delivers at 11lt/min (less now as I have not cleaned out the filters since I changed the cylinder. Edited March 31, 2018 by SteamyTea Link to comment Share on other sites More sharing options...
Hecateh Posted March 31, 2018 Share Posted March 31, 2018 Totally off the wall - but is there a way of sounding an alarm (loud and uncomfortable) after 10 mins rather than stopping the hot. If I was 'rinsing' I wouldn't appreciate either one, but could hurry it up and at least get rinsed off. Or at least some warning when the hot was coming to an end Link to comment Share on other sites More sharing options...
SteamyTea Posted March 31, 2018 Share Posted March 31, 2018 Or a large incoming hot water temperature gauge on each shower. I have always thought that a foot operated valve would be a good idea. Stand on it for water, step off to 'lather up'. Or just get male tenants, 10 year old boys never wash. Link to comment Share on other sites More sharing options...
AliG Posted March 31, 2018 Share Posted March 31, 2018 Does the property have mains gas? If you are including hot water in bills, electric showers are going to cost 4x as much to run as using gas heated hot water. To heat 100l of water by 40c requires almost 5kWH. That means a gas powered shower is going to cost around 15p in hot water and an electric one 65p. 5 people having an electric shower every day is over £1000 a year in electricity. Thus I would definitely go for a large UVC and gas boiler (This is the set up I have gone for and I had exactly the same issue, what if three people want to have showers at the same time). The UVC doesn't have to be 500l as you can store water at 70C and then mix it with cold, but probably you are taking 400l. I would look into low water use shower heads as a way of reducing hot water usage, but I have no personal experience of these. They would also make it easier to have multiple showers running at the same time as they would reduce the necessary flow. If you can reduce the flow rate from a normal 10-12l per minute to 7l then you can have 3 showers for the same amount fo flow as 2 normal showers. That will make life a lot easier. One issue you then need to look at is your incoming water flow. If it is not high enough you would need a cold water tank to supply the UVC. However, this causes issues with the storage of large amounts of cold water. A better solution is a wider pipe to the mains, you could be lucky and already have this and have enough flow, otherwise it will be costly. We just stayed in an Airbnb and they had a big list of instructions for when you should turn the water on etc. My wife just ignored them and kept the heating and hot water on as much as she wanted. At £100 a night it is just cheeky then to ask you to mess around with the hot water. Incidentally we stayed in three Airbnbs whilst waiting for our house to complete, two of the had broken and unreliable boilers, including the one I just mentioned and the other the heating was broken on one floor. I think you are better to make low cost showers foolproof rather than a timer. So lowest cost of hot water and low flow. Similarly use PIR driven lights, LED fittings etc to stop people leaving lights on. All our bathrooms have PIR driven lights now, they are so good I have added more. As for the heating I would be tempted to get a NEST type system so that you can prevent them turning it up to 23C and leaving it on 24 hours a day. That is going to be very tempting when you don't have to pay the incremental cost. Link to comment Share on other sites More sharing options...
Pocster Posted April 1, 2018 Author Share Posted April 1, 2018 (edited) 10 hours ago, AliG said: Does the property have mains gas? If you are including hot water in bills, electric showers are going to cost 4x as much to run as using gas heated hot water. To heat 100l of water by 40c requires almost 5kWH. That means a gas powered shower is going to cost around 15p in hot water and an electric one 65p. 5 people having an electric shower every day is over £1000 a year in electricity. Thus I would definitely go for a large UVC and gas boiler (This is the set up I have gone for and I had exactly the same issue, what if three people want to have showers at the same time). The UVC doesn't have to be 500l as you can store water at 70C and then mix it with cold, but probably you are taking 400l. I would look into low water use shower heads as a way of reducing hot water usage, but I have no personal experience of these. They would also make it easier to have multiple showers running at the same time as they would reduce the necessary flow. If you can reduce the flow rate from a normal 10-12l per minute to 7l then you can have 3 showers for the same amount fo flow as 2 normal showers. That will make life a lot easier. One issue you then need to look at is your incoming water flow. If it is not high enough you would need a cold water tank to supply the UVC. However, this causes issues with the storage of large amounts of cold water. A better solution is a wider pipe to the mains, you could be lucky and already have this and have enough flow, otherwise it will be costly. We just stayed in an Airbnb and they had a big list of instructions for when you should turn the water on etc. My wife just ignored them and kept the heating and hot water on as much as she wanted. At £100 a night it is just cheeky then to ask you to mess around with the hot water. Incidentally we stayed in three Airbnbs whilst waiting for our house to complete, two of the had broken and unreliable boilers, including the one I just mentioned and the other the heating was broken on one floor. I think you are better to make low cost showers foolproof rather than a timer. So lowest cost of hot water and low flow. Similarly use PIR driven lights, LED fittings etc to stop people leaving lights on. All our bathrooms have PIR driven lights now, they are so good I have added more. As for the heating I would be tempted to get a NEST type system so that you can prevent them turning it up to 23C and leaving it on 24 hours a day. That is going to be very tempting when you don't have to pay the incremental cost. Yep have mains gas I guess I want a uvc that is heated via the boiler rather than emertion heater . already have geniushub in 2 other houses works really well - better than nest ? so im guessing 4 showers of uvc with separate tank to feed it . Then I presume the 1 electric shower with pump feeding off that cold tank . Will upgrade the mains anyway and have a water meter ? I just need to understand how extras like hot/cold taps , toilets etc effect all this - but I’m sure nicks on it ! ? Edited April 1, 2018 by pocster Link to comment Share on other sites More sharing options...
Pocster Posted April 1, 2018 Author Share Posted April 1, 2018 Actually how is all this plumbed ? Out of the uvc do you have a manifold ? Supplying each shower for example ? Could I not treat all hot taps like that ? I mean 1 manifold output just for all hot taps ? . Hot tap pressure dropping because another hot tap is in use is less of an issue I assume ... Equally couldn’t all cold taps and toilets run off 1 manifold run from the cold water tank ? Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 36 minutes ago, pocster said: Yep have mains gas I guess I want a uvc that is heated via the boiler rather than emertion heater . already have geniushub in 2 other houses works really well - better than nest ? so im guessing 4 showers of uvc with separate tank to feed it . Then I presume the 1 electric shower with pump feeding off that cold tank . Will upgrade the mains anyway and have a water meter ? I just need to understand how extras like hot/cold taps , toilets etc effect all this - but I’m sure nicks on it ! ? You won't have a gravity cold water storage tank ( CWS ) so you can't have any pumps ANYWHERE . Why upgrade the mains? If an accumulator will suffice you don't need to do that and you may get away without a meter for longer. Do you know the mains pressure / flow rate ? Link to comment Share on other sites More sharing options...
Pocster Posted April 1, 2018 Author Share Posted April 1, 2018 Just now, Nickfromwales said: You won't have a gravity cold water storage tank ( CWS ) so you can't have any pumps ANYWHERE . Why upgrade the mains? If an accumulator will suffice you don't need to do that and you may get away without a meter for longer. Do you know the mains pressure / flow rate ? Ok - I’m confused ! the secondary cold water tank feeds the uvc - got that . thats the 4 showers sorted . The 5th shower I want to keep as electric ; so doesn’t this just pump from that second cold water tank ( that’s real purpose is to feed the uvc ) Perhaps I’m confused by the uvc - does that output hot and cold at pressure ? ( I.e as long as the 2nd tank is supplying it ) Also due to space requirements both tanks will have to be located on the ground floor ( loft will be a converted room ) Link to comment Share on other sites More sharing options...
Jeremy Harris Posted April 1, 2018 Share Posted April 1, 2018 8 minutes ago, pocster said: Ok - I’m confused ! the secondary cold water tank feeds the uvc - got that . thats the 4 showers sorted . The 5th shower I want to keep as electric ; so doesn’t this just pump from that second cold water tank ( that’s real purpose is to feed the uvc ) Perhaps I’m confused by the uvc - does that output hot and cold at pressure ? ( I.e as long as the 2nd tank is supplying it ) Also due to space requirements both tanks will have to be located on the ground floor ( loft will be a converted room ) Bear in mind that even the biggest single phase electric shower will only deliver a bit less than 5 litres per minute of water at around 38 deg C to a shower head, if that. Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 1 minute ago, pocster said: Ok - I’m confused ! the secondary cold water tank feeds the uvc - got that . Ok I'm confused too What secondary tank ? The UVC is cold MAINS fed, so... cold mains stopcock 22mm pipework to uvc multi-block. multi-block has a 3.5 bar PRedv to glean 3.5 bar feeds to both the cold and the hot so you get a "balanced" hot and cold network with both at the same potential. 22mm feed to the UVC from the multi-block 22mm feed to the cold outlets. ( except WC's ). WC's fed from cold main after the stopcock but before the PRedV. outside tap same White goods fed same 15 minutes ago, pocster said: Perhaps I’m confused by the uvc - does that output hot and cold at pressure ? ( I.e as long as the 2nd tank is supplying it ) Explain what you meant by second tank ? A tank is an open plastic box, an accumulator is a sealed giant coke can with a half inch thick rubber bladder inside that gets filled and pressurised to the same pressure as the mains. Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 3 minutes ago, JSHarris said: Bear in mind that even the biggest single phase electric shower will only deliver a bit less than 5 litres per minute of water at around 38 deg C to a shower head, if that. Yup. Electric showers are the anti-Christ. Link to comment Share on other sites More sharing options...
Pocster Posted April 1, 2018 Author Share Posted April 1, 2018 15 minutes ago, Nickfromwales said: Ok I'm confused too What secondary tank ? The UVC is cold MAINS fed, so... cold mains stopcock 22mm pipework to uvc multi-block. multi-block has a 3.5 bar PRedv to glean 3.5 bar feeds to both the cold and the hot so you get a "balanced" hot and cold network with both at the same potential. 22mm feed to the UVC from the multi-block 22mm feed to the cold outlets. ( except WC's ). WC's fed from cold main after the stopcock but before the PRedV. outside tap same White goods fed same Explain what you meant by second tank ? A tank is an open plastic box, an accumulator is a sealed giant coke can with a half inch thick rubber bladder inside that gets filled and pressurised to the same pressure as the mains. Ok ! My bad ! Secondary tank and accumulator are the same thing in my world ?. Will call it accumulator from now on . So all cold water also comes via uvc ? I thought the UVC was fed from the accumulator?? For the electric shower then - it’s fed off cold from uvc ? . If uvc fails will electric shower still get a supply ? sorry - for the confusion. I want to understand this so when I get a plumber in he doesn’t bs me or “ that’ll do mate “ .... Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 3 hours ago, pocster said: I thought the UVC was fed from the accumulator?? The UVC is fed from the cold supply. The cold supply is connected to the accumulator, recharging and discharging accordingly. I'll post a diagram in a bit, easier that way Link to comment Share on other sites More sharing options...
Pocster Posted April 1, 2018 Author Share Posted April 1, 2018 1 minute ago, Nickfromwales said: The UVC is fed from the cold supply. The cold supply is connected to the accumulator, recharging and discharging accordingly. I'll post a diagram in a bit, easier that way Oh ! ? I had assumed mains into accumulator then accumulator into uvc . Can I ask in your diagram you show the electric shower , an ensuite sink and toilet as well . That would be really helpful ! cheers Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 58 minutes ago, pocster said: Can I ask in your diagram you show the electric shower , an ensuite sink and toilet as well . That would be really helpful ! The manifolds can be made to have as many outlets as you require. You would simply connect the electric shower ( yuk ) to an outlet of the cold manifold. Same for the basins / sinks / baths / showers. Simplicity itself, and you can make outlets live as the build progresses. If an item fails, you can just isolate that one outlet and leave the rest of the house working. Link to comment Share on other sites More sharing options...
Pocster Posted April 1, 2018 Author Share Posted April 1, 2018 (edited) 12 minutes ago, Nickfromwales said: The manifolds can be made to have as many outlets as you require. You would simply connect the electric shower ( yuk ) to an outlet of the cold manifold. Same for the basins / sinks / baths / showers. Simplicity itself, and you can make outlets live as the build progresses. If an item fails, you can just isolate that one outlet and leave the rest of the house working. Fantastic ! Much appreciated!! so must I restrict say each output to each shower ? . I.e reduce the flow so multiple showers simultaneously don’t cause pressure loss ? . How do I set this ? Just trial and error ? ( I mean on the manifold ) Edited April 1, 2018 by pocster Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 4 minutes ago, pocster said: so must I restrict say each output to each shower ? . I.e reduce the flow so multiple showers simultaneously don’t cause pressure loss ? . How do I set this ? Just trial and error ? Just fit one of these onto the end of each shower hose, then the handset Link to comment Share on other sites More sharing options...
Pocster Posted April 1, 2018 Author Share Posted April 1, 2018 1 minute ago, Nickfromwales said: Just fit one of these onto the end of each shower hose, then the handset Ok but shouldn’t I have like a valve per shower manifold for hot and cold ? Tenant can’t fiddle with it then . My theory is to run all showers simultaneously as a test and make all valves the same so everyone gets the same ‘shower experience ‘ .... Dont want any chance of flow dropping due to multiple showers in use . Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 11 minutes ago, pocster said: Ok but shouldn’t I have like a valve per shower manifold for hot and cold ? Tenant can’t fiddle with it then . My theory is to run all showers simultaneously as a test and make all valves the same so everyone gets the same ‘shower experience ‘ .... Dont want any chance of flow dropping due to multiple showers in use . No need. You run them all together and then see if they actually need restriction first. If you have the accumulator ( remembering that until we have the details of the main this is all hypothetical ) then you'll have a guaranteed X litres per minute flow, so restricting them will then leave some pressure / flow for other outlets, such as kitchen / utility / cloakroom WC etc etc. Look at it like having a nice V8 engine but only going at 30-40MPH, but you have the option to briefly open the throttle a bit more when needed. Link to comment Share on other sites More sharing options...
Pocster Posted April 1, 2018 Author Share Posted April 1, 2018 (edited) 11 minutes ago, Nickfromwales said: No need. You run them all together and then see if they actually need restriction first. If you have the accumulator ( remembering that until we have the details of the main this is all hypothetical ) then you'll have a guaranteed X litres per minute flow, so restricting them will then leave some pressure / flow for other outlets, such as kitchen / utility / cloakroom WC etc etc. Look at it like having a nice V8 engine but only going at 30-40MPH, but you have the option to briefly open the throttle a bit more when needed. Got you ! ? test then restrict if need be I assume that each manifold output has a isolation / flow restrictor anyway ?? so my Combi ; just does heating and supply the uvc ? Edited April 1, 2018 by pocster Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 Yup. The combi.... What size is it ? Link to comment Share on other sites More sharing options...
Pocster Posted April 1, 2018 Author Share Posted April 1, 2018 (edited) 12 minutes ago, Nickfromwales said: Yup. The combi.... What size is it ? No idea ! ? modern one ; only installed about 2 years ago ... Edited April 1, 2018 by pocster Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 1, 2018 Share Posted April 1, 2018 55 minutes ago, pocster said: No idea ! ? modern one ; only installed about 2 years ago ... Need to know as it'll be heating the system. If it's only a 24/28kw then we may end up going W-plan aka "DHW priority" where it doesn't do space heating and hot water together and any time the hot water needs topping up the system will divert from heating to do so by design. The hot out of the combi will just do the kitchen sink so it ( the moving hot water components etc ) stays active, with the heating output serving the rads and UVC via the W-plan arrangement. Controls can be discussed on a separate thread if you like, when a system is firmly decided upon. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now