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I'm just planning the replacement of the entire hot & cold system in a 5 floor property with 3 bathrooms, 1 cloakroom, kitchen, utility room & laundry room. Would welcome some advice on the design specification:
1) All 3 bathrooms are currently directly fed off the rising main. Pressure at top of house isn't great - especially if other taps are turned on or toilet flushed. I'd also like to fit pump power showers. Question 1 is - I assume therefore the new system should ideally be indirect from a loft cold water storage tank?
2) The hot water is indirectly fed from an existing loft storage tank. On filling a bath it completely empties (and in fact then introduces airlocks into the HW system that needs to be bled out before more HW can be run!). The current tank is obviouslly too small. Given the size of the property and the likelihood that this tank will ultimately need to serve indirect cold as well as hot water, and power showers (as per Question 1), Question 2 is - what size of loft storage tank would you recommend for a property of this size? Current tank is 25Gal, I assume something like 100Gal?
3) To serve 3 bathrooms with power showers I think the current hot water tank is probably too small. What size tank would you recommend for a property of this size (6 bed, 3 bath, 1 cloakroom, kitchen, utility & laundry). So question 3 is what size of hot water tank would be about right? I'm guessing something like Albion 1200x450 166L?
4) Conveniently there is a riser that runs from basement to attic. All of the vertical plumbing can fit into this with horizontal branches off it. I've run through a basic sizing exercise and think that the size of pipwework should be as follows: 22mm up through riser to carry cold water to header tank. 28mm back down the riser to serve indirect cold water. Another 28mm back down the riser to feed cold water to the hot water tank (situated next to the boiler in the basement). Another 28mm back up the riser to carry hot water back up the house. Branches off at each floor to serve bathrooms etc. at 22mm. Then within the bathroom step down to 15mm to serve outlets. Power shower pumps in the bathrooms stay on 22mm. Kitchen, utility room, outside taps & laundry (basement and ground floor) fed directly off the main inlet rather than indirect. Question 4: Do these sizings sounds approximately right?
5) Because the bathrooms are indirectly fed from a header tank with an air gap at the ballcock, and drinking water is directly off the mains... Question 5 - I assume the only places where backflow prevention is required is a double check valve before the two outside taps?
6) The property is over 5 floors - with the boiler & HW tank in the basement and the furthest bathroom is right up in the top floor. Question 6: Would you implement a secondary HW circuit to circulate hot water closer to the upper floors so you don't have to let the taps run for a long time before HW comes through?
Thanks for your suggestions - really just sanity checking my own thoughts before I send a spec out for quotation!
Regards,
Justin Leese, UK
1) All 3 bathrooms are currently directly fed off the rising main. Pressure at top of house isn't great - especially if other taps are turned on or toilet flushed. I'd also like to fit pump power showers. Question 1 is - I assume therefore the new system should ideally be indirect from a loft cold water storage tank?
2) The hot water is indirectly fed from an existing loft storage tank. On filling a bath it completely empties (and in fact then introduces airlocks into the HW system that needs to be bled out before more HW can be run!). The current tank is obviouslly too small. Given the size of the property and the likelihood that this tank will ultimately need to serve indirect cold as well as hot water, and power showers (as per Question 1), Question 2 is - what size of loft storage tank would you recommend for a property of this size? Current tank is 25Gal, I assume something like 100Gal?
3) To serve 3 bathrooms with power showers I think the current hot water tank is probably too small. What size tank would you recommend for a property of this size (6 bed, 3 bath, 1 cloakroom, kitchen, utility & laundry). So question 3 is what size of hot water tank would be about right? I'm guessing something like Albion 1200x450 166L?
4) Conveniently there is a riser that runs from basement to attic. All of the vertical plumbing can fit into this with horizontal branches off it. I've run through a basic sizing exercise and think that the size of pipwework should be as follows: 22mm up through riser to carry cold water to header tank. 28mm back down the riser to serve indirect cold water. Another 28mm back down the riser to feed cold water to the hot water tank (situated next to the boiler in the basement). Another 28mm back up the riser to carry hot water back up the house. Branches off at each floor to serve bathrooms etc. at 22mm. Then within the bathroom step down to 15mm to serve outlets. Power shower pumps in the bathrooms stay on 22mm. Kitchen, utility room, outside taps & laundry (basement and ground floor) fed directly off the main inlet rather than indirect. Question 4: Do these sizings sounds approximately right?
5) Because the bathrooms are indirectly fed from a header tank with an air gap at the ballcock, and drinking water is directly off the mains... Question 5 - I assume the only places where backflow prevention is required is a double check valve before the two outside taps?
6) The property is over 5 floors - with the boiler & HW tank in the basement and the furthest bathroom is right up in the top floor. Question 6: Would you implement a secondary HW circuit to circulate hot water closer to the upper floors so you don't have to let the taps run for a long time before HW comes through?
Thanks for your suggestions - really just sanity checking my own thoughts before I send a spec out for quotation!
Regards,
Justin Leese, UK
