C
craigy
Hello all,
I have been a member for a while but fresh to posting.
I am a plumber with 5yrs experience, qualifications in hot and cold water and licences unvented for your info.
This is the first time I have come across this type of setup in a house so require advice on my action plan.
The type of system in the house I am working on is c/h fully pumped and vented, gravity hot water heated indirectly via coil and mains fed header tank for supply to h/w cylinder. The cylinder is a combination type with the cold supply bang on top of the hot cylinder and fully jacketed(thermal store?) it is a 40/120 cold store/hot store cylinder.
All cold draw offs in the house are mains fed. Incoming mains pressure is 3 bar and flow rate is 16ltr/min off peak.
i am installing a mixer shower with over head square shower head (36sq") and diverted to hand held.
i am putting in a negative head pump 1.5bar.
Knowing the cold storage requirements were not there and the 40ltr for the hot storage was insufficient I have installed 2x18 gallon tanks in the loft and linked them with 22mm copper, I am feeding one tank from the mains with a equilibrium valve delivering 12ltr/min. From the other tank I plan to tap into and feed the pump and just above tap into and send a supply down to the combination cylinder cold storage tank with another equilibrium valve setting both at the same level.
i have considered increasing the overflows in case of overloading should both valves fail.
when I have tested the flow rates from the tank under gravity conditions from the downstairs tap I get 8.5 mins of 12 ltr/min at 60 degrees then it starts to drop, the cold tank which supplies the hot is almost empty at this point as the valve could not allow enough in. Changed the washer and it's much better. I plan an Essex flange from the cylinder to feed the pump.
The only issue I think will lye in the heat recovery, when the temps are mixed I appreciate I will get more than 8.5 mims but I know the pump will pull faster. The boiler is a glow worm regular gas fired piped up in 28 for the big run and down tom22 for the rest.
all my pipe work and connections are 15mm.
Would a circulating pump help the hot water recovery.
should I have the heating element on whilst the coil heats the water too.
the element is not linked to the boiler by the way.
help appreciated.
craig
I have been a member for a while but fresh to posting.
I am a plumber with 5yrs experience, qualifications in hot and cold water and licences unvented for your info.
This is the first time I have come across this type of setup in a house so require advice on my action plan.
The type of system in the house I am working on is c/h fully pumped and vented, gravity hot water heated indirectly via coil and mains fed header tank for supply to h/w cylinder. The cylinder is a combination type with the cold supply bang on top of the hot cylinder and fully jacketed(thermal store?) it is a 40/120 cold store/hot store cylinder.
All cold draw offs in the house are mains fed. Incoming mains pressure is 3 bar and flow rate is 16ltr/min off peak.
i am installing a mixer shower with over head square shower head (36sq") and diverted to hand held.
i am putting in a negative head pump 1.5bar.
Knowing the cold storage requirements were not there and the 40ltr for the hot storage was insufficient I have installed 2x18 gallon tanks in the loft and linked them with 22mm copper, I am feeding one tank from the mains with a equilibrium valve delivering 12ltr/min. From the other tank I plan to tap into and feed the pump and just above tap into and send a supply down to the combination cylinder cold storage tank with another equilibrium valve setting both at the same level.
i have considered increasing the overflows in case of overloading should both valves fail.
when I have tested the flow rates from the tank under gravity conditions from the downstairs tap I get 8.5 mins of 12 ltr/min at 60 degrees then it starts to drop, the cold tank which supplies the hot is almost empty at this point as the valve could not allow enough in. Changed the washer and it's much better. I plan an Essex flange from the cylinder to feed the pump.
The only issue I think will lye in the heat recovery, when the temps are mixed I appreciate I will get more than 8.5 mims but I know the pump will pull faster. The boiler is a glow worm regular gas fired piped up in 28 for the big run and down tom22 for the rest.
all my pipe work and connections are 15mm.
Would a circulating pump help the hot water recovery.
should I have the heating element on whilst the coil heats the water too.
the element is not linked to the boiler by the way.
help appreciated.
craig