DIYnot
Local | Network
   DIYnot > Forums
Local | Network
DIYnot Network Local DIYnot Network Local  
  Forum IndexForum Index     RulesRules    HelpHelp     Join FREERegister Free     About CookiesCookies     SearchSearch     LoginLogin 

FAO ecowarrior etc. How did I do?

Goto page Previous  1, 2, 3  Next
 
Post new topic   Reply to topic    DIYnot.com Forum Index > Electrics UK
Search this topic :: View previous topic :: View next topic  
Author Message
RF Lighting

from United Kingdom

Joined: 31 Mar 2006
Posts: 17194
Location: Leeds,
United Kingdom
Thanked: 890 times

PostPosted: Fri Mar 16, 2012 9:39 pm Reply with quote

I guess that's more suited to where there's multiple boilers?
Back to top
 Alert Moderators

If you do not want to see this advert, click here to login or if you are new click here to join free.
gaswizzard

from United Kingdom

Joined: 08 Oct 2011
Posts: 6277
Location: Hertfordshire,
United Kingdom
Thanked: 986 times

PostPosted: Sat Mar 17, 2012 1:24 am Reply with quote

RF Lighting wrote:




Those 28mm distribution pipes will be an issue with regards to circulators stalling when on full load , not being picky. icon_wink.gif

A handful DPDT relays would be the way to go , I prefer the Drayton RB1.
Back to top
 Alert Moderators
matt1e

from United Kingdom

Joined: 13 Dec 2008
Posts: 2215
Location: Tyne and Wear,
United Kingdom
Thanked: 226 times

PostPosted: Sat Mar 17, 2012 9:31 pm Reply with quote

and the LLH isn't plumb as well as the flue looks as though it has been "forced" over as it certainly is not in line with the boiler.
I'm not being picky either though icon_mrgreen.gif
Back to top
 Alert Moderators
xr4x4

from United Kingdom

Joined: 01 Oct 2009
Posts: 2836
Location: Hampshire,
United Kingdom
Thanked: 252 times

PostPosted: Sat Mar 17, 2012 9:42 pm Reply with quote

What's the black box below the boiler?
Back to top
 Alert Moderators
gaswizzard

from United Kingdom

Joined: 08 Oct 2011
Posts: 6277
Location: Hertfordshire,
United Kingdom
Thanked: 986 times

PostPosted: Sat Mar 17, 2012 10:03 pm Reply with quote

xr4x4 wrote:
What's the black box below the boiler?


A low loss header which is supplied with 2" tappings. icon_wink.gif
Back to top
The following user says thank you to gaswizzard for this useful post:
xr4x4 (17 Mar 2012)
 Alert Moderators
xr4x4

from United Kingdom

Joined: 01 Oct 2009
Posts: 2836
Location: Hampshire,
United Kingdom
Thanked: 252 times

PostPosted: Sat Mar 17, 2012 10:07 pm Reply with quote

gaswizzard wrote:
xr4x4 wrote:
What's the black box below the boiler?


A low loss header which is supplied with 2" tappings. icon_wink.gif


Ok thanks..

What does it do....!
Back to top
 Alert Moderators
gaswizzard

from United Kingdom

Joined: 08 Oct 2011
Posts: 6277
Location: Hertfordshire,
United Kingdom
Thanked: 986 times

PostPosted: Sat Mar 17, 2012 10:19 pm Reply with quote

Ok , i'm gonna start being picky , no more mr nice guy......................watch this space.

icon_lol.gif
Back to top
 Alert Moderators
ecowarrior

from United Kingdom

Joined: 21 May 2010
Posts: 8236
Location: Northamptonshire,
United Kingdom
Thanked: 2152 times

PostPosted: Sun Mar 18, 2012 9:25 am Reply with quote

the black box (Low Loss Header) does various things. The pump on the boiler inst big enough to supply the whole system under full load - so the boiler pump ( now called a shunt pump) only needs to pump the hot water from the boiler to the LLH. It is sized up for the boiler (presumably this is a 60Kw LLH) It also helps the boiler keep its designed delta T across the outputs to reduce thermal shock across the heat exchanger.
It also means the the boiler services the LLH rather than all the various demands the other 4 zones have. It can also be used to 'even out' using 2 boilers. So if 2 x 30Kw were used on a cascade then their joint inputs would go into this LLH to be distributed to the various zones. This is done for various reasons - break downs being the obvious one , as at least one boiler will still b running but if a very small load is at times required then the ratio of max to min modulation on the boiler ( lets say its 6:1 means max mods on a 60 is 60 but the min 10.) if the min loading is 5 Kw then the boiler will cycle uneciserily. So using two boilers @30 with 6:1 means with only one boiler running the lowest o/po is only 5Kw.

This is not my area of expertise & GW & LeeC do these every day. I do see where GW is going with his 28mm pipe though,. I am sure more knowledgeable people than me on these things will add or correct.
A not so clued up plumber ( or one just putting in a cheaper quote to get the job) would just bang on a slightly larger head pump in the boiler and pipe it straight up to zones via valves. It would still all work to a fashion and everything would probably still get hot - but it would not be ' due dilation'
This is a good example of a big house installation. Added to this there could be W/C on each (or just some) circuit and even different flow temperature requirements on differing zones.
Back to top
The following user says thank you to ecowarrior for this useful post:
xr4x4 (18 Mar 2012)
 Alert Moderators
matt1e

from United Kingdom

Joined: 13 Dec 2008
Posts: 2215
Location: Tyne and Wear,
United Kingdom
Thanked: 226 times

PostPosted: Sun Mar 18, 2012 3:58 pm Reply with quote

Thats a pretty good discription eco, I will just add in case it wasn't clear that any system demands ie valves closing ,pumps turning on off or ramping up/down etc have no effect on the flow through the boiler
Eco's mention of the boiler shunt pump is what me and gaswizzard were getting at when we commented on ebees earlier post on the first page
"the big loop" ebee refered to is also a low loss header and the pump he thought "should be bigger" would have been specified to match the boiler req flowrates etc
around the header, the size of the system punps have no baring
Matt
Back to top
The following user says thank you to matt1e for this useful post:
ecowarrior (18 Mar 2012)
 Alert Moderators
ecowarrior

from United Kingdom

Joined: 21 May 2010
Posts: 8236
Location: Northamptonshire,
United Kingdom
Thanked: 2152 times

PostPosted: Sun Mar 18, 2012 6:50 pm Reply with quote

Just been reading thru this again- have to have a chuckle at the sparkies & their 'ELV' & the plumbs with their 'LV'

I gave up with 'ELV' ages ago or no plumbum has a clue what u r referring to. Its like u have to hang up the phrase when u purchase a set of bending bars!
Even the boiler MU's call it 'low voltage side' and '230 volts side'
Back to top
 Alert Moderators
RF Lighting

from United Kingdom

Joined: 31 Mar 2006
Posts: 17194
Location: Leeds,
United Kingdom
Thanked: 890 times

PostPosted: Sun Mar 18, 2012 9:50 pm Reply with quote

As usual the sparkies are right though icon_wink.gif
Back to top
 Alert Moderators
Dan_Robinson

from United Kingdom

Joined: 01 Jul 2007
Posts: 26415
Location: Hertfordshire,
United Kingdom
Thanked: 4049 times

PostPosted: Sun Mar 18, 2012 11:05 pm Reply with quote

Nah, just as equally, selectively pedantict icon_wink.gif
Back to top
 Alert Moderators
kevindgas

from United Kingdom

Joined: 28 Mar 2006
Posts: 5689
Location: Southampton,
United Kingdom
Thanked: 465 times

PostPosted: Sun Mar 18, 2012 11:09 pm Reply with quote

forgive my ignorance on low loss headers but how does the system expansion get taken? doesn't the low loss header keep heating circuits seperate from the boiler circuit? is it not like a huge plate to plate?
Back to top
 Alert Moderators
gaswizzard

from United Kingdom

Joined: 08 Oct 2011
Posts: 6277
Location: Hertfordshire,
United Kingdom
Thanked: 986 times

PostPosted: Mon Mar 19, 2012 12:00 am Reply with quote

kevindgas wrote:
forgive my ignorance on low loss headers but how does the system expansion get taken? doesn't the low loss header keep heating circuits seperate from the boiler circuit? is it not like a huge plate to plate?


A low loss header provides hydraulic seperation between boiler/s and system circuit/s , it's basically a large vessel whereby flow velocity is minimal therefore creating circuit seperation between primary/secondary circuits.

The water in the secondary circuits mix with the water in the primary circuits (boilers/radiators) , flow rates for ring/header circulator/s must be equal too or exceed flow rate for secondary circulator/s.
Back to top
 Alert Moderators
kevindgas

from United Kingdom

Joined: 28 Mar 2006
Posts: 5689
Location: Southampton,
United Kingdom
Thanked: 465 times

PostPosted: Mon Mar 19, 2012 8:34 am Reply with quote

can i have that in english now please!! does or does it not keep the two halves seperate? i:e like a plate to plate or is it just like a 4 pipe boiler where the 2 mix together inside?
never got involved in big stuff hence i know nought about these things.
Back to top
 Alert Moderators
Search this topic :: View previous topic :: View next topic  
Post new topic   Reply to topic    DIYnot.com Forum Index > Electrics UK All times are GMT
Goto page Previous  1, 2, 3  Next
Page 2 of 3

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


 
DIYnot
Find an Expert | Find a Supplier | Search DIYnot.com
Network | Advertising | Newsletter
DIY | DIY How To | @home | DIY Wiki | DIY Forum
By using this site you agree to our Terms of Service / Disclaimer.
Please read our Privacy Policy. Copyright © 2000-2014 DIYnot Limited.