what's a 1 pipe system?

[holty]

love this bit on that link

Q: Do you have to take any special precautions with the upfeed gravity system?
A: Yes, if you have to drain the system, be careful how you refill it. Start off with all the radiator vents open. Then, slowly fill the system, one floor at a time. When water flows from the vents on the first floor, quickly close them all. Then, continue filling until water rises to the second floor. Shut all the air vents and move up to the third floor. Once you have all the radiators filled, fill the system to the one-third-full point in the expansion tank.

 

[twgas]

This is an interesting read:
http://www.oldhouseweb.com/how-to-advice/gravity-hot-water-heating.shtml[/QUOTE] had a quick read of some of this, then got a little disheartened "A cubic foot of water at 180 degrees F takes up about five percent space than a cubic foot of water at 40 degrees F".

It's called expansion twgas

Everything expands as it gets hotter.

I know it expands as it heats, but that would make it more than a cubic foot

 

[dextrous]

This is an interesting read:
http://www.oldhouseweb.com/how-to-advice/gravity-hot-water-heating.shtml[/QUOTE] had a quick read of some of this, then got a little disheartened "A cubic foot of water at 180 degrees F takes up about five percent space than a cubic foot of water at 40 degrees F".

It's called expansion twgas

Everything expands as it gets hotter.

I know it expands as it heats, but that would make it more than a cubic foot

Somehow I think you know exactly what it means.

 

[doitall]

That's why you have expansion vessels and expansion tanks (header tank)

 

[doitall]

Did you know if you buy a cubic metre of water, and boil it you get 50 cups of tea for free

 

[twgas]

Did you know if you buy a cubic metre of water, and boil it you get 50 cups of tea for free

does that not depend on how hot the water is when you buy it

 

[dextrous]

Did you know if you buy a cubic metre of water, and boil it you get 50 cups of tea for free

Would you care to expand on that?

 

[doitall]

Did you know if you buy a cubic metre of water, and boil it you get 50 cups of tea for free

does that not depend on how hot the water is when you buy it

Indeed it has to be boiling. or 98c in Bournemouth

 

[D_Hailsham]

Very rarely see a bypass on a one pipe. That would just reduce the flow cumulatively.

If there is no bypass, what happens when someone closes a radiator or a TRV?

Answer: All rads get cold because there is no circulation.

 

[doitall]

I know what you mean Dave.

 

[mehran]

can also get one pipe systems were they flip the flow direction.

so 30min one way then 30 min the other...

help to reduce any "cold last rad" problems

 

[holmslaw]

It's called expansion twgas

Everything expands as it gets hotter.

That is wrong.

 

[doitall]

can also get one pipe systems were they flip the flow direction.

so 30min one way then 30 min the other...

help to reduce any "cold last rad" problems

Never heard that one Mehran, are you sure you're not having a funny moment

 

[doitall]

It's called expansion twgas

Everything expands as it gets hotter.

That is wrong.

I'm all ears

 

[mehran]

can also get one pipe systems were they flip the flow direction.

so 30min one way then 30 min the other...

help to reduce any "cold last rad" problems

Never heard that one Mehran, are you sure you're not having a funny moment

i heard that the germans do it that way... sounds plausible to me. also heard installers using this trick to get out of problems when they bugger up the system design.