Direct air kit (multi-fuel stove 5kw)

[Smcmullan88]

 

We are having a stove fitted which is 5kw nominal output and will insert into a chimney breast on an external wall.  The stove supports an external air source using a direct air kit but we can’t decide whether to get this or not.
 

Due to regulations because our stove is 5kw or under and the house built before 2008 (2003 to

be precise) we don’t have to put this in.  
 

However I have seen so much conflicting advice on this and wondered if anyone had any advice or thoughts?

 

Things that concern me about the direct air:

1. A draught from the stove when not in use
2. Drilling a hole in the external wall for not much of an additional benefit 

3. The “room - sealed” stove being leaky so when the stove is off it makes the room colder.

 

Things that concern me not getting the direct air:

1. Enough draw to fuel the stove (this should be fine i would imagine)
2. A cold draught pulling across the room from other sources to fuel the fire

Any advice would be appreciated and for the record here is the stove: 

 

Ecosy Newburn 5 Wide

https://www.stoveworlduk.co.uk/ecosy-newburn-5-wide-idyllic-5kw-defra-approved-ecodesign-multi-fuel-stove-5-year-guarantee

 

Thanks

[ProDave]

The whole point of the direct air kit is it makes the stove ROOM SEALED so you DO NOT get "a draught from the stove when not in use"

 

It means it draws it's combustion air direct from the outside.

 

Without the direct air kit, the stove will draw it's combustion air from the room, sucking already warm air from the room and likely still sucking some heat from the room when the stove is not lit.  The stove will have to get it's air from somewhere so without the direct air kit is where you will get draughts across the room.

 

Just because you are not forced by building regulations to do something, is not a reason not to do it.  Most of us on here view building regulations as a minimum standard and strive to make things a lot better than the bare minimum requirements.

[JohnMo]

The other thing to add is the building airtightness.  An airtight building needs an external air feed, as the stove has to pull air from somewhere.  

 

If you have a tight house ie using MVHR you need this external air to get the correct flue draw, otherwise you will have difficulty lighting the fire and lots of smoke entering the room when you open the door.

 

Things that concern me about the direct air:

 

1. A draught from the stove when not in use - no as ProDave explained 

2. Drilling a hole in the external wall for not much of an additional benefit - see answer to 1.

 

3. The “room - sealed” stove being leaky so when the stove is off it makes the room colder. If it's leaky you have more to worry about, the carbon monoxide leaking out when lit will kill you

 

Things that concern me not getting the direct air:

 

1. Enough draw to fuel the stove (this should be fine i would imagine), see what I said about airtight house

2. A cold draught pulling across the room from other sources to fuel the fire

 

find and download manufacturer install manual and read it.

 

 

[saveasteading]

In Scotland you now need an air feed for 5kW or more.

The more I think of it , the more a direct feed is the right solution, even for under 5kW.

 

I first intended to fit a louvre close behind the burner, as this would provide the air, yet not cause a draight.

But it must not have a closer, so it will inevitably create a draught.

We have put in a 60mm pipe from outside, then through the PIR to behind the stove position. In due course it will be connected into the back of the stove, as yet not selected.

It can all be plastic until close to the stove.

 

I am hoping that more manufacturers start allowing the rear air entry, as currently they are very expensive.

 

As a bonus , opening the vents will create stack ventilation, if ever needed.

 

[Smcmullan88]

I understand this all your points are very valid so thank you for this.

 

The issue I have is people are saying they manufactures often lie about the room sealed part and there is no way for a truly room sealed stove.  The direct air kits are the bit I am talking about leaking - the smoke only goes up the flue therefore no co2 will leak from the air kit but cold air will get in when the stove is not in use.  This is my biggest concern.  We have a very cold and draughty house in the winter.  We do not want to add to the problem.  This is why I’m torn.

 

Thanks

[ProDave]

That raises an important point.  Check with the stove manufacturer before you buy, that both primary and secondary air are drawn from the duct.  Not all of them are, so some with a ducting kit are not true room sealed stoves.

 

If there is an air leak from the ducting kit, it is wrongly fitted.  That should not be a concern.

 

and once the stove is in,  work on fixing some of the other leaks to make the house less draughty.

[JohnMo]

Our direct air connection was a pain to get to, to correctly tighten the hose clips, so the installer did his best efforts without strip down if the stove. He tried to bodge and hope no one was watching or checking.

 

That is sometimes the issue, the installer takes shortcuts.  I didn't accept the short cut and the fitter had to take some of the stove apart to fit the hose clips correctly, took about 20mins to do the job right.

 

Our building air test had no leaks at the stove or the outside air connection.

[Smcmullan88]

fair points I have asked the question and will see what they respond.  I would imagine though it is probably only the really expensive stoves that are drawing the air in from the duct on the primary and secondary only.  I am sure the stoves that can be added to be the kit probably don’t offer the same control.  Probably still worth having anyway judging by what you are all saying rather than not having.

 

Thanks

[Smcmullan88]

reply from the supplier below, does this make sense and is it good / bad / indifferent?  Also can you control the amount of air coming in through the Vent? 

 

When using the direct air supply, all of the stove’s air will be drawn from the duct.

 

 

Thanks

[JohnMo]

Makes sense primary and secondary air come from duct.  Outside air connection is just a hole in the wall connected to stove by a duct.  Air is controlled the same way with or without duct via normal stove control 

[Smcmullan88]

forgot this bit sorry:

 

Both levers control the air flow into the stove itself. When using the direct air supply, the function of the stove is still exactly the same, but the air is just drawn in from outside rather than from the room.

 

 

so all good then go with direct external  air supply ?