I've just had a gander at some of the messages in this section, there's some good stuff here, members evidently know their stuff.
I hope that I'll be pointed in the right direction.
Presently I have a 1st floor gravity fed tank (25 gal cold header in the loft), hot feed by garage boiler. When it's sunny, fed by a 18 tube rack via a heat exch (in the immersion heater access hole), tubes are positioned south facing but is shaded from 10am to 7pm.
Realistically, this tank only supplies taps, and the shower is mains cold, electric 7kW, costs a fortune to run.
I have now fitted 2 evacuated tube racks to the roof (no tubes in yet), piped it through the slate, and hope to have a tank in the loft.
Because of building regs (hi pressure stored water), I opted for a vented system, so the tank will have to be higher than the cylinder (in the loft).
The shower is on first floor.
The cold tank will be head hight in the loft, so the available head of water for the shower will be about 2metres.
The problem i cant fathom is the pressure that is available for the safety control devices.
Because of the potential higher temp that the cylinder may rise to, I'm assuming a tempering valve is needed (instead of a blend valve), these can cope with 95degC possibilities.
Running down to the shower, will be a thermostatically controlled mixer, (cold inlet side will be fed from the cold tank (balanced pressures).
The sink/bath taps will be fed from the cylinder / tempering valve.
Regarding the shower, will there be enough pressure in the 2m head to ensure the effective operation of both mixers?
I inderstand that devices can work with 0.1 bar pressure, but there may not be enough pressure left for a good flow of shower water, despite being run in 22mm copper.
Is it likely that I need a booster pump on hot/cold shower feeds.
If so, between what points in the piping should the pump be fitted, I've never used one, but understand it senses the water trickle when the shower valve is opened and activates the pump (until the valve is closed).
Also, I heard a while back, that fitting a number of thermostatic mixers in the same run can cause them to fight against each other. Not sure if there's any truth in it, perhaps it was a mashup about not using a tmv with a non-modulating boiler perhaps.
Anyway, I considered a thermal store/heat bank, but because of price and having to ensure piping hot water for an efficient heat exchange, I'm going for vented. I may use a high pressure unvented cylinder, but gravity fed/ vented to atmpsphere, (so that in the future, if I want to change over, it's in place and just needs commissioning by one of the many friendly G3 wolvo plumbers).
If there is a better way to do this, then I'm open to suggestions. If models / makes could also be specified with any guidance please, that would help me to understand the parameters a bit better.
With mixer valves being used, is it an idea to get a strainer in line or would all the detritus just fall to the bottom of the cold tank.
I'm hopefull of including (eventually) a heat recovery option from the shower grey water, to pre warm the shower mixer cold inlet. No big ask there then!
Thanks in advance for any suggestions.
(This was submitted yesterday, but doesn't seem to be in the thread, so resubmitted. Pls ignore if diplicated).
I hope that I'll be pointed in the right direction.
Presently I have a 1st floor gravity fed tank (25 gal cold header in the loft), hot feed by garage boiler. When it's sunny, fed by a 18 tube rack via a heat exch (in the immersion heater access hole), tubes are positioned south facing but is shaded from 10am to 7pm.
Realistically, this tank only supplies taps, and the shower is mains cold, electric 7kW, costs a fortune to run.
I have now fitted 2 evacuated tube racks to the roof (no tubes in yet), piped it through the slate, and hope to have a tank in the loft.
Because of building regs (hi pressure stored water), I opted for a vented system, so the tank will have to be higher than the cylinder (in the loft).
The shower is on first floor.
The cold tank will be head hight in the loft, so the available head of water for the shower will be about 2metres.
The problem i cant fathom is the pressure that is available for the safety control devices.
Because of the potential higher temp that the cylinder may rise to, I'm assuming a tempering valve is needed (instead of a blend valve), these can cope with 95degC possibilities.
Running down to the shower, will be a thermostatically controlled mixer, (cold inlet side will be fed from the cold tank (balanced pressures).
The sink/bath taps will be fed from the cylinder / tempering valve.
Regarding the shower, will there be enough pressure in the 2m head to ensure the effective operation of both mixers?
I inderstand that devices can work with 0.1 bar pressure, but there may not be enough pressure left for a good flow of shower water, despite being run in 22mm copper.
Is it likely that I need a booster pump on hot/cold shower feeds.
If so, between what points in the piping should the pump be fitted, I've never used one, but understand it senses the water trickle when the shower valve is opened and activates the pump (until the valve is closed).
Also, I heard a while back, that fitting a number of thermostatic mixers in the same run can cause them to fight against each other. Not sure if there's any truth in it, perhaps it was a mashup about not using a tmv with a non-modulating boiler perhaps.
Anyway, I considered a thermal store/heat bank, but because of price and having to ensure piping hot water for an efficient heat exchange, I'm going for vented. I may use a high pressure unvented cylinder, but gravity fed/ vented to atmpsphere, (so that in the future, if I want to change over, it's in place and just needs commissioning by one of the many friendly G3 wolvo plumbers).
If there is a better way to do this, then I'm open to suggestions. If models / makes could also be specified with any guidance please, that would help me to understand the parameters a bit better.
With mixer valves being used, is it an idea to get a strainer in line or would all the detritus just fall to the bottom of the cold tank.
I'm hopefull of including (eventually) a heat recovery option from the shower grey water, to pre warm the shower mixer cold inlet. No big ask there then!
Thanks in advance for any suggestions.
(This was submitted yesterday, but doesn't seem to be in the thread, so resubmitted. Pls ignore if diplicated).
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