Boiler vents at property boundary.

[Frank Erskine]

All you'd have to do is to erect a wall also up to the boundary, directly facing his flue terminal....

;-)

[Geoff]

Hi,

Does anyone know if there are any regulations governing where vents can be placed?

My neighbour's garage comes right up to our boundary. He had work done on his house that coverted the garage to a kitchen and that set of "workers" put the vent for the boiler about a foot in from the boundary but facing up the drive. Now they have tried to move it to have it coming out of the wall facing my property. Unfortunatley, there is not enough space left on his property and it would come over the boundary line slightly. So I slightly said, "No way." But assuming there had been just enough space, is it permiissible for someone to site vents so that they immediately put the exhaust fumes over another property?

[Dave Plowman (News)]

A decent boiler allows the flue to be extended vertically to get over any such problem.

[auctions]

600mm clearance needed according to my quick reading of the regs. A

[Ed Sirett]

There are a load of rules governing this. IIRC The flue has to be at least 2.5m from the property boundary, at that distance any remaining visible plume will be drifting upwards anyway.

[Geoff]

[Heliotrope Smith]

There does not seem to be any regulation preventing a flue discharging over a boundary, just recommendations to keep the discharge on the property in which the appliance is fitted.

There are regs of course on minimum distances from adjacent buildings and structures.

If the flue terminal itself is over your boundary then that is another matter.

[dennis]

If its a condensing boiler what produces the mist? How much don't they condense out and how much heat is wasted because they don't? I just wondered when a new super condensing boiler was going to be required if the condensing ones are so bad they leave troublesome plumes?

[Andrew Gabriel]

The condensate.

Depends on the return water temperature.

The plume is as a result of condensate. If it was still steam, that's invisible.

[Andy Hall]

The byproduct of combustion is water in the form (initially) of steam - meaning water in the gaseous state. This is invisible and should not be confused with what many people all "steam", the visible cloudy stuff. That is water vapour and consists of very tiny droplets of water.

There is latent heat of condensation which is the heat released when the steam changes state from the gaseous (invisible) to liquid (visible) states. The heat exchanger of the boiler is able to use that and it's added to the combustion heat.

The important thing is that the condensation takes place in the heat exchanger itself and so the performance depends on the temperature of the coolest part of the exchanger - i.e. the return water temperature.

Some boilers do a good job of collecting the condensate at the water vapour stage in the boiler itself so that it goes to the drain. Others are not so good at that and it comes out of the flue as a plume.

From the heat recovery point of view, it doesn't make much difference because any further realistic heat recovery after the water has become visible vapour is not very much at all - i.e. as long as the actual condensing to visible vapour goes on inside, that's what really matters. Presence or absence of the visible plume doesn't signify much at all in terms of the final efficiency of the boiler.

[Andrew Gabriel]

There's one, I've heard, which has no condensate drain, and explicitly injects the condensate into the flue gas as its method of disposal.

[LSR]

Nope. Water vapour is invisible and < > water droplets. Otherwise air would be translucent on a humid day.

[Andy Hall]

The important point is the difference between the gaseous and liquid phases in terms of latent heat and that the visible stuff is the liquid phase, i.e. post condensation having happened.

[Bob Mannix]

Indeed but I think his point was that "vapour" is only gaseous!

[Andy Dingley]

According to your recent post, heat from lights causes condensation...

[Dave Liquorice]

And the visible stuff is what the man in the street would call "steam". Water vapour is invisible. Not as Mr Hall said in his post.

[Ed Sirett]

IIRC, This is the Atmos which is favoured by you-know-who this season.

[Andy Hall]

Do they have a range of puffy anoraks with a pocket for the Ian Allan trainspotting book?

[Andy Hall]

That point is neither here nor there. What actually matters is the point at which the latent heat is released and that is before there is a visible plume.

[dennis]

And if it had condensed and given up its heat to the heat exchanger it would drip off and not be a plume.