Atmos or Intergas

[Steelmasons]

You don't know much about low-loss headers do you?

I have asked you twice now for the specs regarding the low loss header on the other thread to which you have ignored , you have some gall is all I can say.

Now give me those header specs for the 45 kw vaillant.

 

[Steelmasons]

Oh dear , just read this thread to which it appears alexcarp has been 'searching' for threads regarding low loss headers

Trust me Alex you will not get an answer on Google let alone the plumbing forum.

'Must try harder' being a moot point.

Now run away just like brightonguy did.

 

[Dan Robinson]

Aahh.... Brightonguy. I remember him.

He was an idiot too.

Wait.


He concocted a similar builshit system.


Hhhhmmmmm.

 

[Steelmasons]

Bringing up an old thread here which is relevant as I used the content to fit a system in an average semi.

I took note of the Intergas boiler and the low loss header to give zoning of upstairs and down and independent TRV temperature control in each room with no central thermostat control.

A low loss header was made up using 28mm pipe and fittings like this, but running horizontally under the boiler.

The two heating zones could have different flows through their own circuits, and sometimes very low flows, so the low loss header guarantees a constant high flow through the boiler giving full boiler protection. The flow and returns to each heating zone were 22mm. The two heating flows were taken from one end of the header. The header also had the filling loop attached. I thought the header of 28mm may be too small, and I was prepared to up the size after testing, which would not be a great job to do, but it works fine.

A 40 kilowatt Intergas combi was used.

28mm diameter low loss header??? , Surely you are referring to a manifold?

The velocity through the 28mm tube @ 40kw load would hardly be 'low loss'

Your homework for today is to calculate the flow rate/velocity through that 28mm tube @ 40kw load......I would guess velocity would be in excess of the preferred 0.3 metres/second.

 

[Dan Robinson]

Aaawww... He's run away again Steel.

 

[AlexCarp]

Read what I wrote, it was clear enough. I am referring to a 28mm header. The area of two 22mm pipes is more than the area of one 28mm pipe, so this was marginal. But the flows through the two circuits would not be high. I had some 28mm pipe and fitting so used them to see if it worked. If not the next size up would be used.

The Intergas boiler pump was set to low. The 40 kilowatt combi boiler was chosen as it was a cheap deal. The next one down would have done. The DHW output was the prime choice and the two top models of Intergas have exactly the same DHW output.

The house needs nowhere near 40kW of heat. The boiler starting from cold is on full belt and all the flow runs through the two flow heating pipes with none running back to the boiler via the header. The towel rail was piped not from the header but from the boiler's flow and return to ensure it is on when any heating zone is operating, so some by-pass of the header flow making sure all the hot water goes into the heating zone's flow pipes.

On start up, you can hold your hand on the header in the centre and it is cool while the flow from the boiler is very hot. The flow from the boiler is taken right out and into the radiators 100% by the two smart pumps. The return water from the reads is taken right back into the boiler 100%.

I did the test with a thermometer and my hands. When the house warms up and hence the return warms up the boiler modulates down to suit as it knows the house is warming up. The TRVs start to close down and the smart pumps do not pump fully out of the header as they wind down their speeds. Then the flow from the boiler to its return short cuts via the header, as the boiler pump is stronger than the two smart pumps as they have wound down. Again the boiler modulates its gas burner down. But the max flow temp is governed by the weather compensator, so overall temperatures in the flow and return are low in the vast majority of run time giving a high efficiency in condensing using less gas.

This is a similar situation as the guy from Manchester wanting to fit the 46 kilowatt boiler. If I was him I would go to the next size up for the header, 35mm copper. The pipe and fittings from http://www.bes.co.uk are cheap enough at about £50 or so including 3m of 35mm pipe. What 35mm pipe is left over can be fitted at the gas meter for the gas supply to the combi.

There you go. Easy.

 

[Steelmasons]

So tell me alex what is the flow rate and velocity through the 28mm 'header'.

Please refrain from reffering to it as a low loss header.

Do you actually know what a low loss header achieves?

 

[doitall]

Read what I wrote, The boiler starting from cold is on full belt and all the flow runs through the two flow heating pipes with none running back to the boiler via the header. You can hold your hand on the header in he centre and it is cool while the flow from he boiler is very hot. The flow from he boiler is taken right out and into the rads 100%. The return water is taken right back into the boiler 100%. It did the test with a thermometer and my hands.

There you go. Easy.

Impossible so I'll assume you're living up to your name and talking carp.

Of course the as installed may be nothing like your pic (header)

 

[Steelmasons]

You can hold your hand on the header in he centre and it is cool while the flow from he boiler is very hot.

....and another keyboard fooked.

You fool.

 

[Steelmasons]

32mm copper tube???????

On what basis did you calculate a header size of 35 mm (yes it is 35mm and not 32mm tube size) , I suggest you hang that shovel up.

 

[AlexCarp]

Read what I wrote when testing. Even you may get it after a time.

 

[AlexCarp]

Read what I wrote, The boiler starting from cold is on full belt and all the flow runs through the two flow heating pipes with none running back to the boiler via the header. You can hold your hand on the header in the centre and it is cool while the flow from the boiler is very hot. The flow from the boiler is taken right out and into the rads 100%. The return water is taken right back into the boiler 100%. It did the test with a thermometer and my hands.

There you go. Easy.

Impossible

I gave you my findings. Totally correct. Read what I wrote. The two heating zones take all the flow from boiler on start up. NO water short circuits running through the low-loss header. NONE I never made it up.

 

[doitall]

And as I said impossible, even if you take the pump from the return and fit it in the flow after the manifold.

 

[AlexCarp]

And as I said impossible, even if you take the pump from the return and fit it in the flow after the manifold.

I know what I tested an what I got. The two heating pumps on the flows, combined pumped more than the primary header pump in the boiler. All the flow from the boiler HAS to run into the heating circuits. BTW, I did the header like the Keston diagram earlier in the thread. The flow and return from the boiler enters the header at the very ends of the header. So flow from the boiler into the end of the header and then right out into the two heating circuits.

When the TRVs close up and the smart pumps wind down the primary header pump will pump more than the two of them and then water will flow right along the header to the return to the boiler. This is all very obvious.

The area of the two 22mm pipes is more than the area of one 28mm pipe. But as the primary pump will be at its lowest speed and the Smart pumps run up and down to suit I thought this marginal, but fitted the 28mm header as I had the fittings. If it did not work I would have gone up to 35mm copper pipe for the header, a simple thing to do. If I did not have the 28mm pipe and fittings at hand I would have put in 35mm as belt and braces approach.

This is a superb cheap way of getting two heating zones and TRVs on all radiators. The boiler will last longer having a guaranteed flow through its heat exchanger.

 

[Steelmasons]

Let's recap regarding your estimation on low loss header size regarding the 40kw boiler @ 20c temp differential using a 28mm low loss header , considering you changed your mind let's calculate velocity rates for the 35mm low loss header while we're @ it.....bear in mind velocity rates should preferably be around 0.3 m/s.

40kw load requires a flow rate of 0.48l/s

28mm low loss header @ 0.48 l/s would yield a velocity rate of 0.89 meters/second......FAIL.

35mm = 0.57 m/s......FAIL.
42mm = 0.48 m/s...... we're getting close....
54mm = 0.23 m/s.......we're good to go.

As you can see the Googlers/idiots get caught out pretty quickly.

....and you had the nerve to suggest another member was not familiar with low loss header sizing....

Have you completed your homework for today Alex???? , me thinks not.