Low Loss Headers
- Thread starter feebeebos
- Start date
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Hi Softus,
I only heard about this on Thursday, a guy on a course always installs them into his heating systems but didn't have time to explain.
Have a look at this and like me be baffled
http://www.contractormag.com/articles/column.cfm?columnid=487
Hopefully someone will be able to provide some simple explanation, pics etc
Regards
I only heard about this on Thursday, a guy on a course always installs them into his heating systems but didn't have time to explain.
Have a look at this and like me be baffled
http://www.contractormag.com/articles/column.cfm?columnid=487
Hopefully someone will be able to provide some simple explanation, pics etc
Regards
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Just found this which goes some way to explain what Low Loss Headers are all about. Just installing a Valliant Ecomax at home so want to get as much info as I can to incorporate a LLH into the system if I can
Shouldn't we all be oot supping beer! Tis Sat nite
Shouldn't we all be oot supping beer! Tis Sat nite
Ooopps forgot to include the hyperlink
http://www.pmmag.com/CDA/Archives/38b99783250d7010VgnVCM100000f932a8c0____
http://www.pmmag.com/CDA/Archives/38b99783250d7010VgnVCM100000f932a8c0____
Low loss headers are not necessary for normal domestic installations. They are only appropriate for very large domestic or commercial installations where the pump built into the system boiler would not be able to cope with the demands of the system.
Where have you been hiding Chris?
We really need John the Scruff to give a good reply as most of the systems he fits use them.
I will try my best to explain how they operate!
Firstly, they are usually used on complex systems with heating demands of 40 kW upwards. The one exception was a simple boiler, the Chaufateau Flexiflame 140,000 BTU which had one fitted underneath as part of the system, it was widely used in launderettes during the 1980s.
The boiler output is put through a thick tube of say 52 mm upwards about 500 mm long so that if there is no demand the boiler output is shortcircuited and the boiler modulates down.
At each end of the "header" the flow and return is connected with its own circulating pump. In a maximum load condition the flow from the header will equal the flow from the boiler so there will be no flow through the 52 mm headder.
To anyone with RF electronics knowledge its rather similar to a 3 dB Coupler!
Sorry to anyone else, but its not such an easy concept to understand if you are familiar with it. Its not that important usless you are involved with industrial or large domestic!
Tony Glazier
I will try my best to explain how they operate!
Firstly, they are usually used on complex systems with heating demands of 40 kW upwards. The one exception was a simple boiler, the Chaufateau Flexiflame 140,000 BTU which had one fitted underneath as part of the system, it was widely used in launderettes during the 1980s.
The boiler output is put through a thick tube of say 52 mm upwards about 500 mm long so that if there is no demand the boiler output is shortcircuited and the boiler modulates down.
At each end of the "header" the flow and return is connected with its own circulating pump. In a maximum load condition the flow from the header will equal the flow from the boiler so there will be no flow through the 52 mm headder.
To anyone with RF electronics knowledge its rather similar to a 3 dB Coupler!
Sorry to anyone else, but its not such an easy concept to understand if you are familiar with it. Its not that important usless you are involved with industrial or large domestic!
Tony Glazier
Thats a vertical header which is exactly the same only much larger.
The idea is the primary water circulates around the header the muliple system flow and returns can then have a seperate zone with it's own pump and the smaller pumps are unaffected by the larger one.
It was common with larger system that when more than one pump was running for the larger one to rob the smaller pump and stop the circuit flowing, it has been known to actually reverse the flow through the pump.
Hope that all makes sense.
The idea is the primary water circulates around the header the muliple system flow and returns can then have a seperate zone with it's own pump and the smaller pumps are unaffected by the larger one.
It was common with larger system that when more than one pump was running for the larger one to rob the smaller pump and stop the circuit flowing, it has been known to actually reverse the flow through the pump.
Hope that all makes sense.
http://www.viessmann.co.uk/products/technical-documents.php
click on vitodems Range tecchnical guide, open the pdf and scroll down to page 92
click on vitodems Range tecchnical guide, open the pdf and scroll down to page 92
DIA's pic shows the vertical header on the right - saying that just so I can point out that I know what they are )
Take note of the sentence in the writer's article
Well quite, remember many US homes are 19 times bigger than ours. The Viessmann app note is for multi-boiler installations.
Having said that, the "big manifolds with a pipe between" is common enough on UFH installations, and is sort of a bit similar, and you can of course get pre-made setups or build your own from standard parts.
http://www.antaresint.com/PUBLIC/foto/E.600.jpg
http://www.antaresint.com/PUBLIC/foto/E.631.jpg
http://www.antaresint.com/PUBLIC/foto/E.633.jpg
An RF 3dB coupler is a device in plumbing terms designed to give you half the pressure you had before. Not the same thing at all to my mind!
)Take note of the sentence in the writer's article
Well quite, remember many US homes are 19 times bigger than ours. The Viessmann app note is for multi-boiler installations.
Having said that, the "big manifolds with a pipe between" is common enough on UFH installations, and is sort of a bit similar, and you can of course get pre-made setups or build your own from standard parts.
http://www.antaresint.com/PUBLIC/foto/E.600.jpg
http://www.antaresint.com/PUBLIC/foto/E.631.jpg
http://www.antaresint.com/PUBLIC/foto/E.633.jpg
An RF 3dB coupler is a device in plumbing terms designed to give you half the pressure you had before. Not the same thing at all to my mind!
But you get TWO outputs of 1/2 making a whole.
An RF 3dB coupler can also be used the other way round to combine two transmitter outputs!
Its not exactly the same I agree, probably a four port hybrid ring would be closer.
Tony
Later edit for Chris, nope, a 3 dB coupler has four ports but one or two of them are terminated depending on the application. If one is terminated it can be used as a splitter or combiner. If two are terminated it can be used to improve matching.
An RF 3dB coupler can also be used the other way round to combine two transmitter outputs!
Its not exactly the same I agree, probably a four port hybrid ring would be closer.
Tony
Later edit for Chris, nope, a 3 dB coupler has four ports but one or two of them are terminated depending on the application. If one is terminated it can be used as a splitter or combiner. If two are terminated it can be used to improve matching.
Your memory is failing you Tony - a coupler has one input, one out.
A matched splitter may be what you're thinking of.
I can think of analogies from other fields but I don't think this is an arena for expounding such things!
A matched splitter may be what you're thinking of.
I can think of analogies from other fields but I don't think this is an arena for expounding such things!
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