Any plumbers / heating engineers in here?

[Justme]

Hi,

Can any one either tell me or point me in the right direction to find out how high a head of water I need to produce a given presure using a given size of pipe work?


Only need .3 bar min & the major lenght of pipe will be 25 or 19 mm blue alcothene. Its to supply water from a tank to a static caravan so that the gas water heater will work as they have no mains water.

Oh & if its a problem whats the max height I should use?


Justme

 

[Haze]

10 feet = 30 kp or 0.3 bar, pipework sizing doesnt alter pressure, only flow.

 

[Haze]

oh and i would think 100 feet would be the maximum head you could use, but thats a guess cus it depends on the water heater.

 

[Justme]

Cool thanks. We dont have 100 foot to play with but up to 25 ish. So that should be fine.

Only metioned pipe sizing as the presure is in PSI & as the crossectional diamiter is greater even at the same presure a bigger pipe would have more surface area on its section so a greater total presure applied at the same PSI (more surface area = more presure exerted at same given presure).


Justme

 

[rtbcomp]

Cool thanks. We dont have 100 foot to play with but up to 25 ish. So that should be fine.

Only metioned pipe sizing as the presure is in PSI & as the crossectional diamiter is greater even at the same presure a bigger pipe would have more surface area on its section so a greater total presure applied at the same PSI (more surface area = more presure exerted at same given presure).


Justme

Not quite - more surface area = more FORCE exerted at same given presure

 

[Haze]

more surface area = more presure exerted at same given presure

lol at that tbh

 

[Alex]

Plumbers and heating people aren't engineers.

Thats why the status of engineers is not high anymore.

 

[Haze]

I beg to differ, engineers design and build, so a professional pipe fitter would design a system and build it, the root of the word engineer explains this, tbvh the status of an engineer has been elevated above its station.

 

[rtbcomp]

Speaking as someone who can't drop a brick vertically I certainly wouldn't denegrate pipe fitters and the like!

 

[Cappy]

Plumbers and heating people aren't engineers.

Thats why the status of engineers is not high anymore.

Hope any engineer might enjoy these - there are more

1 - To the optimist, the glass is always half full
To the pessimist the glass is always half empty
To the engineer the glass is bigger than it needs to be

2 - What is the difference between mechanical and civil engineers?
Mechanical engineers build weapons and civil engineers build targets

3 - Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.

Have a nice day

 

[Haze]

lol nice

 

[lexi]

Plumbers and heating people aren't engineers.

Thats why the status of engineers is not high anymore.

Every trade is doing more fitting now. There are still a lot of guys in all these trades who know their stuff...........and more!

Alex

 

[rtbcomp]

If a software engineer (LMFAO) can't fix a bug he calls it a feature.

 

[Justme]

wood fired heating system

Ok while we are on the heating / plumbing topic.


I am looking at changing my oil fired central heating for a wood fired one. I know you can get mega bucks off the shelf solutions but I am looking for a lower tec system. So to set the picture.
We cook on a rayburn that burns wood. It also provides the hot water to the taps via a tank (low presure vented). The cental heating is oil fired closed system presurised. We have a wood fire in the living room.

Options we have looked at are

1, change living room fire to a back boiler version
(poss put thermal store tank on too so one big burn at night can give heat out in the morning)

2, change cooker to bigger one that can do the rads as well

3, change oil boiler for a wood fired one
(poss put thermal store tank on too so one big burn at night can give heat out in the morning)


Each one has its merrits & draw backs.

To make matters worrse it needs to be power cut safe (have looked at battery / inverter back up for the curculation pumps but dont want computer controls).

Has anyone here got direct experiance of such a change / system?


Justme

Ps we have looked at ground source pumps but they are not power cut safe & solar water collectors CANT do HEATING no matter what you might have been told.

 

[rtbcomp]

If you use a wood burner to heat water make the upstairs radiators thermo-sysphon fed so they don't need the pump. If necessary increase the pipe bore from 15mm to 22mm to make flow easier. Don't use thermostatic valves on a couple of rads for extra safety.

I had a back boiler with four connections, one side was the gravity feed to upstairs, the other pair were pump fed for the downstairs.

A friend of mine powered his central heating via a 13A plug & socket so he could plug it into a generator when the power failed.

 

[berendd]

Ps we have looked at ground source pumps but they are not power cut safe & solar water collectors CANT do HEATING no matter what you might have been told.

solar water collectors can do heating, but as you will need heat when the sun isn't shining it's useless...

why do you need a power cut safe system, so much powercut overthere???

what about a natural gas or wood stove as a backup for a ground sourced heatpump system? overall efficiency will not be affected by those couple of hours a year you need the backup...

btw, yes I'm an HVAC engineer and consider myself an engineer...

 

[Haze]

number 3 would probably suit the best, but fit an electric element to the cylinder, it will be more efficient this way, in a power cut the element wont work obviously so the system will be less effective, but it will still provide what you need.

I've never changed a oil system to a wood burning one, but all the principles are the same.

heat source -> store -> taps/rads

 

[Haze]

If you use a wood burner to heat water make the upstairs radiators thermo-sysphon fed so they don't need the pump. If necessary increase the pipe bore from 15mm to 22mm to make flow easier. Don't use thermostatic valves on a couple of rads for extra safety.

why a couple?

A friend of mine powered his central heating via a 13A plug & socket so he could plug it into a generator when the power failed.

as opposed to a fused spur? gosh thats forward thinking

 

[Justme]

Wow food for thought.

Why would a electric element increase efficiency? Trying to reduce comsumption not increase it.

Dint think of using the outlets in pairs with pumped & un pumped. That would work best on the back boiler option. How many rads can you thermo syphon? Would it do 4 / 5 upstairs rooms with 7/8 rads & a spread of 7/8 meters? Most people only have one / two thermo syphone rads for safety reasons.

solar water collectors can do heating, but as you will need heat when the sun isn't shining it's useless...

why do you need a power cut safe system, so much powercut overthere???

what about a natural gas or wood stove as a backup for a ground sourced heatpump system? overall efficiency will not be affected by those couple of hours a year you need the backup...

btw, yes I'm an HVAC engineer and consider myself an engineer...

We have no nat gas supply & bottled gas is like oil to much money.

Yes we have lots of power cuts in teh winter. Had 3 this winter. Most are only for a few hours some are over night or longer.

Other problem with ground source heat is you realy need to either vastly increase the size of the rads or use under flour heating as the tempreture is much lower than from a boiler. Both are costly options (as is ground source any way). Also need a large input of power & we want to reduce our electricity comsumption to sensible levels. For the solar you would need a seriously large array to produce 100,000 plus btu,s & like you said when it could its no use. Also mega bucks.

Ok so sizing the boiler is fairly simple calc (volume of rooms, insulation, windows, room type, local weather conditions plus some, temp needed) but how do I size the thermal store so I can do one burn (with refills if needed during the evening so that in the morning it will release enough heat to warm the house back up?

The more I look the more questions seem to apear.

Justme

 

[Justme]

as opposed to a fused spur? gosh thats forward thinking

Our solution might be to power it through a computer UPS (with uprated battery to give longer life). Fully automatic operation then.

Justme