How wide should I build my chimney?

[Matt60]

I have bought a Parkray Aspect 7 LPG gas stove from my friend who deals really only in wood burners and as such is unable to advise me on chimney and flue specifications. He bought the stove at a show on a whim because he was so impressed with it.

 

I have called my Gas Safe registered plumber and he has advised me to contact the manufacturer but I cannot afford to wait for potentially no reply or no info.

 

Simply, I need to know how big to make the internal chimney diameter (my chimney breast is being built right now) to suit this stove and what type of liner it needs to have. I really need this information as soon as possible as my bricklayer has already started the chimney breast, wants to continue, but can’t until I supply him the info requested above. I see that the Aspect 7 has a 127mm diameter flue (or 5”) so should I make the clay liner 6”? or 8”?

 

I would be really grateful for any help you can give me so I can set my bricklayer building it again, I have attached the brochure and installation instructions for the fire.

 

Thanks in advance for any wisdom on this.

 

As a side note; I chose this over a wood burner because I can't be arsed to source wood, load the thing or clean it out. I know this is not quite as nice as a wood burner but the convenience for me far outweighs any negatives. It also makes it easy to have a gas hob and therefore I will save some money there verses an induction hob. 

FINAL_Hunter_Gas_Brochure_2019.pdf HUNTER_STOVES_6KW_GAS_INSTRUCTIONS_JIN06KWGAS_REV_E_05072019.pdf

[crispy_wafer]

Looks nice, and practical too, however for me, i'd Install a full fat 8" liner, that way you'd be covered if you ever changed your mind.  Wont cost you an awful lot more in materials either.

[epsilonGreedy]

I cannot answer the main question but I wonder if conventional chimney design thinking needs to be amended for the extra moisture content of gas combustion?

[Temp]

On 09/08/2021 at 16:23, Matt60 said:

I see that the Aspect 7 has a 127mm diameter flue (or 5”) so should I make the clay liner 6”? or 8”?

 

I'm not a Hetas installer but I would build a 150mm or 225mm ID diameter chimney using pumice liner blocks. Then use a register plate/adapter to connect to the stove. They can be painted black to match the stove pipe.

 

The manual here..

https://www.hunterstoves.co.uk/Content/Images/uploaded/Instructions New/Aspect Eco Dry Instructions.pdf

says..

 

Connection to the Chimney An existing fireplace opening can be bricked up or sealed with a register plate. A short length of flue pipe of minimum 125mm internal diameter may then be used to connect the stove to the chimney. This flue pipe should be made of 316 grade stainless steel or vitreous enamelled steel, nominal thickness 1.2mm.

 

Something like this or one with a flat rectangular plate that can be screwed to the underside of the cast lintel..

https://directflues.co.uk/isokern-dm36/adaptor-increasing-stainless-125mm-to-150mm-isokern

 

Do check exact dimensions before ordering. Took me three attempts to get the right adaptor for my stove.  They mixed up ID and OD and things like that. I think some places make them to order.

 

I note that the manual also says...

 

The stove should stand wholly above a solid, non-combustible hearth, at least 125 mm thick (this may include the thickness of a solid floor).

 

There is a diagram in the relevant Approved Document that describes this. In short this means the stove may raise the temperature of the hearth over 100C or at least its not certified that it wont. The latter would allow a thinner hearth (eg 20mm slate/granite/glass).

[Matt60]

Thanks for the replies to this, I thought I had already replied but obviously not. Incidentally, in the true fashion of building, my bricklayer wanted all this decided and the materials to execute by the 10th of August but today on the 4th of September he hasn't started that bit yet... 

 

Thanks again,

 

Matt.