is there a simple cheap fix to boost pressure to one single domestic tap outlet?

martco

We've been handed a pain of a problem by an environmental health officer.
I have a small business in its first year, its a little coffee deli takeaway, simple service counter + a coffee machine etc. We are virtually a market stall inside a building (although quite professional we're literally that level) & there's virtually nil food prep being done at the service counter but we have a small panini grill to do hot sambos which seems to put us in the crosshairs....

Anyway on to the plumbing problem!
To satisfy the requirements I did install 2 sinks out at the service counter one for washing hands, mixer tap in the middle. The cold is ok as its mains fed and decent pressure BUT the hot pressure is poor. It's poor but does work however this doesn't seem to impress the environmental health officer (I think she's being unreasonable but there's no point in that argument) and we were given a directive to improve its performance.

This problem hot water tap is fed from a standard copper water immersion cylinder at the back of this single storey building...its approx 12M away on the ground level, the immersion cylinder sits directly under the storage water tank feeding it, it has a drop of maybe 2M at most. tho I'm not a plumber I think this is the problem in the end.

So in summary - the storage water tank feeds the immersion cylinder 2M below it at ground level and the tap I need to improve is about a 12M run away also on the ground level.

I have a limited budget, also I can't really afford to close the place during the working week. I've reasonable basic plumbing skills so I'm hoping I'd love to sort this out myself on a Sunday.

The bit of research I've done seem to indicate that the boost pumps are all a bit over the top for what I need in this case as all the other hot water taps in the rest of the building at the bathroom and kitchen (by virtue of being closer to the immersion cylinder I think) seem to operate satisfactorily so I'm not sure I need to boost the whole system.

Is there such a thing as a small & simple automatic in-line boost pump that I could plumb in to just this problem hot water tap spur? or maybe there's some unintended bodge I could use to solve this? I ask because I'm finding it difficult to find such a thing so far in my searching...all seems to be £600+ fancy and physically large Grundfos gear and complicated re-plumbing project work.

suggestions very welcome, thanks!

Sleeper12

I see two options. One is install a pump.
Two fit an under sink water heater. Feed the under sink heater with mains water. This will give you balanced hot and cold pressure. You need to check if this holds enough hot water for you first

Calahonda52

OP:
who pays for the hot and cold water?
is the Envo bod not concerned that 12m of water need to pass before it gets hot or it just a pressure/flow issue?
Its possible that the mixer tap maybe designed for high pressure...
Is the cylinder just for you or are there other users in the building.
The under sink idea by S12 will work assuming you have room for it and have a power supply.
You will need a timer on it to make sure it goes off at night and is hot at opening time

martco

her issue is maybe a bit of both tho she didn't seem to understand to the level of 12m worth of water having to pass etc. that not specifically mentioned..pressure/flow ..so if I turn on the mixer tap to hot it takes about 10-15 secs to reach me, the flow is poor granted

my building nobody else involved, don't think its the mixer tap but I'll check

the under sink water heater might be a runner, never thought of that, there might be enough space and there is a socket closeby behind the cabinets...I'll look at this for sure

also I saw one inexpensive pump that might also work, I could place at the cylinder end, called a "Salamander CT55+ Xtra 1.6 Bar Single Impeller Regenerative Pump" it seems to suggest in the docs that it could provide a simple single tap feed...

Calahonda52

okay, would it be possible to run a second pipe and a cable to the cylinder from the HW tank.\
If so then you could put a circulation pump at the tank on a loop from the HW tanks and use an air-switch at the sink to tell the pump to circulate and you would have instant hot water. There are energy loss considerations but it you use the air switch then its on demand only.
the circulation pump has to be a bronze pump so not cheap.

So it importnat to find out is it delay or pressure is her problem as I don't recall seeing volume rules for hand washing when I had a cafe : my guess is it is a delay

If the plumping is not clear for this solution come back to us

martco

thanks chaps
I had a chat with a decent man at the counter in DPL, I've gone for a neat 5L water heater which isn't too heavy and wont need any structural cable work, I'm going to fit myself on Sunday...lets see!

RobAMerc

martco wrote: »

her issue is maybe a bit of both tho she didn't seem to understand to the level of 12m worth of water having to pass etc. that not specifically mentioned..pressure/flow ..so if I turn on the mixer tap to hot it takes about 10-15 secs to reach me, the flow is poor granted

my building nobody else involved, don't think its the mixer tap but I'll check

the under sink water heater might be a runner, never thought of that, there might be enough space and there is a socket closeby behind the cabinets...I'll look at this for sure

also I saw one inexpensive pump that might also work, I could place at the cylinder end, called a "Salamander CT55+ Xtra 1.6 Bar Single Impeller Regenerative Pump" it seems to suggest in the docs that it could provide a simple single tap feed...

I bought an instant hot water tap on ebay - its effectively a kettle that sits under the sink and constantly heats water ( not just instant )
I haven't noticed my ESB bills going up much ( to be fair I dont regularly check it )

this might be a good option for you

Edit: I see you got sorted before I could complete my post - fast work !

antiskeptic

martco wrote: »

We've been handed a pain of a problem by an environmental health officer.
I have a small business in its first year, its a little coffee deli takeaway, simple service counter + a coffee machine etc. We are virtually a market stall inside a building (although quite professional we're literally that level) & there's virtually nil food prep being done at the service counter but we have a small panini grill to do hot sambos which seems to put us in the crosshairs....

Anyway on to the plumbing problem!
To satisfy the requirements I did install 2 sinks out at the service counter one for washing hands, mixer tap in the middle. The cold is ok as its mains fed and decent pressure BUT the hot pressure is poor. It's poor but does work however this doesn't seem to impress the environmental health officer (I think she's being unreasonable but there's no point in that argument) and we were given a directive to improve its performance.

This problem hot water tap is fed from a standard copper water immersion cylinder at the back of this single storey building...its approx 12M away on the ground level, the immersion cylinder sits directly under the storage water tank feeding it, it has a drop of maybe 2M at most. tho I'm not a plumber I think this is the problem in the end.

So in summary - the storage water tank feeds the immersion cylinder 2M below it at ground level and the tap I need to improve is about a 12M run away also on the ground level.

I have a limited budget, also I can't really afford to close the place during the working week. I've reasonable basic plumbing skills so I'm hoping I'd love to sort this out myself on a Sunday.

The bit of research I've done seem to indicate that the boost pumps are all a bit over the top for what I need in this case as all the other hot water taps in the rest of the building at the bathroom and kitchen (by virtue of being closer to the immersion cylinder I think) seem to operate satisfactorily so I'm not sure I need to boost the whole system.

Is there such a thing as a small & simple automatic in-line boost pump that I could plumb in to just this problem hot water tap spur? or maybe there's some unintended bodge I could use to solve this? I ask because I'm finding it difficult to find such a thing so far in my searching...all seems to be £600+ fancy and physically large Grundfos gear and complicated re-plumbing project work.

suggestions very welcome, thanks!

Example from another field. My factory equipped with a compressed air supply. If you take a short 6mm airline in the workshop and plug it into the 2" mains air supply, the pressure at outlet of the hose would blow a hole through your hand. Rig up a 50m length of 6mm hose to work on something at a distance and the pressure at outlet would be bettered by someone blowing out hard with their lungs!


The issue is pressure loss through a pipe. Length of pipe, convulutions in the pipe and diameter of pipe contribute to pressure loss along the way. You could try the simple fix of increasing the diameter of the supply line. If it's 1/2" for example, increasing to 3/4 (or two 3/4" even, teeing off at cylinder exit and teeing together just before the sink) would reduce the pressure loss (increase pressure and thus, flow rate) at the sink outlet. Consider too that every elbow and tee point is a point of pressure loss, so straightening out the run in so far practical will add to increased flow

Check too, very importantly, the actual orifice size in the sink tap and any other fittings along the line ( an inline isolation valve, a non-return valve, etc). A nominally 1/2 valve might have a smaller orifice internally which effectively throttles the flow. Increase the size of these valves to ensure the oriface size through the valve matches the general pipework internal diameter (3/4")

Name of the game: large diameter pipe/fittings all the way along the line: from supply tank to cylinder and from cylinder to tap. Relatively cheap and, depending on access, relatively painless and quick to achieve

Consider the flow you'd get if the header tank supplying the sink was situated directly above the sink and you had a large feed pipe from header to a large orifice sink tap. You'd have a veritable deluge at the sink. The only thing preventing those circumstances now is pipeline restrictions > pressure loss. Remove the pressure loss and you increase the flow.

Calahonda52

the larger diameter argument is fine, up the point where you consider water loss/heat loss in a pipe run, which shows as diameter doubles, X sectional area, and thus water volume goes up by 4 times
Pie.............radius.......radius..... X sectional area
3.14 0.25 0.25 0.20
3.14 0.38 0.38 0.44
3.14 0.50 0.50 0.79

Some of the more well known formulae for head loss/pressure loss are nicely summarised here
https://en.wikipedia.org/wiki/Darcy–Weisbach_equation

Pressure loss and head loss are a fn of velocity squared, as well as diameter and length.....

Dtp1979

Calahonda52 wrote: »

the larger diameter argument is fine, up the point where you consider water loss/heat loss in a pipe run, which shows as diameter doubles, X sectional area, and thus water volume goes up by 4 times
Pie.............radius.......radius..... X sectional area
3.14 0.25 0.25 0.20
3.14 0.38 0.38 0.44
3.14 0.50 0.50 0.79

Some of the more well known formulae for head loss/pressure loss are nicely summarised here
https://en.wikipedia.org/wiki/Darcy–Weisbach_equation

Pressure loss and head loss are a fn of velocity squared, as well as diameter and length.....

What's an air switch?

antiskeptic

Calahonda52 wrote: »

the larger diameter argument is fine, up the point where you consider water loss/heat loss in a pipe run, which shows as diameter doubles, X sectional area, and thus water volume goes up by 4 times
Pie.............radius.......radius..... X sectional area
3.14 0.25 0.25 0.20
3.14 0.38 0.38 0.44
3.14 0.50 0.50 0.79

Some of the more well known formulae for head loss/pressure loss are nicely summarised here
https://en.wikipedia.org/wiki/Darcy–Weisbach_equation

Pressure loss and head loss are a fn of velocity squared, as well as diameter and length.....

Under Practical application in the wiki article, my bold:

"Doubling the diameter of a pipe of a given schedule roughly doubles the amount of material required per unit length and thus its installed cost. Meanwhile, the head (or pressure - antiskeptic) loss is decreased by a factor 1/32 (about a 97% reduction). "

martco

well I solved the problem in the end by myself as intended, Sleeper12's idea thanks!

I bought a small under sink water heater, 5L capacity which plugs into a normal 13A wall socket, despite the size it seems to work very well (apart from keeping the EHO happy...she did check it out on the visit and was very happy)
The only issue I had involved mains pressure - ironically it was proving too strong but the heater unit came with a pressure relief valve which seems to solve the problem all operates well

Glad I had a go myself, I learned a bit and saved a fair few quid too!

thanks everyone