Stove advice

[Justin]

I am getting ready to put a stove in to keep us warm over the winter months, i have spotted this one on the net ,

 

http://www.stovesareus.co.uk/catalog/produ...fc33002edd6e076

 

 

it is a 7kw output and is a little large, do people think this is to big for a boat ? we want to be as roasty as possible but dont want to set fire to my newly installed tongue and groove!!

 

Opinions grstefully recieved

 

Justin

[stuart]

I am getting ready to put a stove in to keep us warm over the winter months, i have spotted this one on the net ,

 

http://www.stovesareus.co.uk/catalog/produ...fc33002edd6e076

it is a 7kw output and is a little large, do people think this is to big for a boat ?  we want to be as roasty as possible but dont want to set fire to my newly installed tongue and groove!!

 

Opinions grstefully recieved

 

Justin

<{POST_SNAPBACK}>

 

This link seems to work better!

 

http://www.stovesareus.co.uk/catalog/produ...products_id=355

 

Evergreen ST1047 sp/offer

 

This tremendously popular single door stove is also available in double door

Heat output 7 kW

Width 460mm

Height 610mm

Depth 420mm

Flue Size 6" (152mm)

Ht Ctr Rear Flue 420mm

Flue Options Top or Rear Flue (interchangeable)

Optional Boiler 12,000 btu

 

 

 

[John Orentas]

Justin.

 

Looks like a great stove, good size and right price.

 

John Squeers

[timboharticus]

The Morso squirrel is very popular, partly because it can be turned down low.

 

This stove seems very powerful, I would be a bit worried that you would tend to operate it at low air and it may not work as well as a smaller stove.

[Rick]

We have a Morso Squirrel on our boat but haven't yet fired it up. The only negative comments I have heard from other Squirrel owners is that, even in the depths of winter they have to open a door to let the heat out.

 

I would suspect that a 7Kw fire might be too big.

 

Richard

[Paul Evans]

See here for details of the Morso Squirrel:

 

http://www.stovesonline.co.uk/wood_burning...rel-Stove.html#

 

It costs more than the Evergreen but has a lower heat output rating. I'm thinkng of 7 1Kw electric fires strung out down the boat. Do you really want the tropics indoors?

[Justin]

Thank you all for your opinions, i am up to the boat tomorrow, i will check at midland chandlers the stoves they have in. then decide And take the plunge after that. decisions decisions this fit out game is a bit of a minefield!! thanks for the advice

[John Orentas]

Justin.

 

I still think it is a good buy, there are a lot of prophets of doom on this site. The rating of 7 Kilowatt should be regarded as a maximun output in ideal conditions. Looking at the pictures there seems to be plenty of control provision with high and low vents, and dare I say it looks like a more attractive and better quality unit than the Morso.

 

The general consensus is that 7 Kw is about right for a central heating system, so there is no reason that the same should not apply to solid fuel stoves.

 

John Squeers

Edited October 19, 2004 by John Orentas

[Paul Evans]

If you added the boiler to the Evergreen (£150), thermostat, pump, pipe runs etc you could have a calorifier with another coil and heat water, run a couple of radiators and a heated towel rail. That would use up some of the surplus heat (or at least move it about). All you need is the cash, diagram and time to do the work!

[stuart]

If you added the boiler to the Evergreen (£150), thermostat, pump, pipe runs etc you could have a calorifier with another coil and heat water,  run a couple of radiators and a heated towel rail. That would use up some of the surplus heat (or at least move it about). All you need is the cash, diagram and time to do the work!

<{POST_SNAPBACK}>

 

I'm thinking about doing just that with this stove. I've been told that I need to be careful of the pressure in the hot pipes running to rads and calorifier - but if I fit an expansion tank at the end of the system surely that will take care of that?

 

Do I need to worry about the hot water boiling or is that almost impossible due to the size of the radiators and convection of heat etc?

[Paul Evans]

Sorry! Missed the expansion tank out of my list but then I'm no central heating engineer - just full of (good?) ideas.

 

I don't know how you would control the heat in the system to prevent boiling but I bet there's somebody out there who can help. Roll on the central heating wizards!

[John Orentas]

Paul.

 

I am not one of them but:

 

You don't need to rely on a pump but the size of the radiators must be such that they can disperse all the heat the stove can produce. The pipes must be of a sufficient diameter, and installed with enough constant angle to allow the natural convection of the water.

 

A header tank must be fitted as high as practical, and the pipe leading up to it should be as short as possible and connected at the very hightest point of the top pipe so that air cannot accumulate, the diameter must be big enough to allow air bubbles to readily pass through.

 

No real figures, but that's the priciple.

 

John Squeers

Edited October 22, 2004 by John Orentas

[Martin]

MachineMart do this stove too (or at least a practically identical one - with the Clarke name on it. £376 is their price tag.

They do cheaper and smaller ones too.

Check out MachineMart for further details - go to the Heating & Ventilation pages within Product Search.

[stuart]

A header tank must be fitted as high as practical, and the pipe leading up to it should be as short as possible and connected at the very hightest point of the top pipe so that air cannot accumulate, the diameter must be big enough to allow air bubbles to readily pass through.

 

No real figures, but that's the priciple.

 

John Squeers

<{POST_SNAPBACK}>

 

Am I correct in thinking that the expansion tank can go anywhere in the c/heating loop? I've got a full length cupboard planned half way down the boat and would like to put this into the top of that.

 

Where do you get the expansion tanks from anyway ???

Edited October 25, 2004 by stuart

[John Orentas]

Stuart.

 

The header tank must connect at the highest point of the loop, remember that air bubbles must find their way up to the tank so the connection pipe must be as short, straight and as vertical as possible.

 

Making a fully convecting system that works reliably and looks ok is not easy, thats why most people go for a pumped system, you can take more liberties with the design.

 

Header tanks, you can sometimes find a vehicle header tank that will do the job, but remember you will need a big bore connection at the bottom, don't use a pressure cap, alternatively have a brass one made.

 

John Squeers

Edited October 25, 2004 by John Orentas

[Justin]

would it be possible to plumb the boile of the stove in to the the same system as webasto central heating which already has header tank? im guessing not as the webast is the pump as well, and would need to be on to move the water but ho hum any ideas

 

Justin

[Noah]

Justin

 

Sorry no expert help from me, just some ideas (some from experience of DIY solid fuel central heating in my house). Next year I'm thinking of doing the same as you suggest here and so I'm reading others' views with interest. I too have a diesel (Mikuni) boiler with integral water pump. The Mikuni is in the rear engine compartment and the Morso Squirrel is at the front of the boat. As I already have radiators, I don't want to modify the pipework drastically. However, the "end" rad is very close to the stove. I am considering fitting a boiler to the stove (a Morso dealer assures me that this can be done) and connecting into the nearby radiator.

 

In a totally pumped system (as mine will be), hot water cannot dissipate sufficiently by gravity and therefore the pump must be switched on as soon as the stove reaches operating temperature or boiling-over and damage will occur. In my system at home, a hot water cylinder (calorifier) also receives hot water, although by gravity, thereby allowing an escape for excess boiler heat when the radiators' pump is switched off. A domestic heating engineer tells me that this arrangement can be improved with the addition of thermostats to switch the pump automatically whenever the cylinder exceeds a pre-set temp (say 80C). The same engineer ran a mile when asked how to couple-up by stove to a coal back-boiler in another room! I suspect it can be done, but would require a complex system of valves and thermostats. As for applying this to my boat, I' wondering if I can simply (or not) switch the Mikuni water pump on without activating the Mikuni boiler. This way I could have the benefit of "free" central heating whenever the stove is lit. This will also disperse about one third of the kWs away from the Squirrel, which is too hot to sit near without windows and doors open!

 

I hope this lot is of some interest. When I make a start on my boat, I may find it more complicated than this, but I'll be smug if it works (and cursing if it dos'nt!). Has anybody else tried linking two central heating systems, or retro-fitted a boiler to a Squirrel?

 

Noah

[John Orentas]

Noah

 

Just a couple of points to add to that. Fitting a back-boiler to a stove is not going to give any more total heat than a stove on it's own, the only advantage is that some of the heat produced is taken up by the water in the system, which in turn gives up it's heat in another place via a radiator.

 

Connecting the stove to a nearby radiator, if that was literally meant, can be a complete waste of time.

 

As you imply, the idea of having two heat sources in a single system heating radiators is a nightmare, there would be so many odd sonarios and wierd possibilities. Better to keep two independant systems, even if it means an extra radiator or two.

 

John Squeers

Edited October 28, 2004 by John Orentas

[Rick]

I have fitted, after advice, my expansion tank where convenient and put an automatic air bleed valve at a carefully constructed high point. The bleed valve was at the suggestion of Karunda where I bought the Bolin c/h pump, 12v and.15 (point 15)amps, pipe stat extra.

 

Richard

[dor]

Fitting a rad CAN increase the heat output from the stove. The stove will radiate only so much - a direct result of surface area and temperature. The rest of the heat goes up the chimney. A boiler can take some of the heat away.

To prevent boiling, I once had a domestic system with a large wood-fueled multi-stove, in series with an oil boiler. (The oil boiler was just used to top up in cold weather - or when the stove went out.). Because the heat output of the stove was very high, it could easily boil if the rads were not on, even though there was a 28mm gravity syphon to a hot tank above. I solved this by putting a tank stat on the pipe immediately behind the boiler. If the water got to about 90deg it switched on the pump to dump the heat into the rads.

Edited October 29, 2004 by dor

[John Orentas]

dor

 

Not quite sure about your phisics here. I can't see how fitting a back-boiler can reduce the amount of heat being lost up the chimney.

 

It is not really the case that the the stove can only radiate so much, it will always be the same as the heat generated, it's a closed system, apart from, as you say the heat lost up the chimney but that won't vary much. In fact most of the heat from the stove is given up directly to the air surrounding it, radiated heat is rather less.

 

As an approximation, if your stove is a cube shape one fifth of the inside area will be the boiler (the bottom doesn't do much) so 20% of the output will go to heating the water.

 

John Squeers

Edited November 1, 2004 by John Orentas

[Noah]

This all seems to be getting more complex than it needs to be. After all, I enjoy my boat more when things are kept simple, and therefore less prone to problems. I even binned the TV that came with the boat when I bought it, just to keep things low-tech! I think John O is probably right to suggest keeping heating systems separate and so avoid problems that are almost certain to arise in the depths of winter. If I have another boat I will insist on one system, probably a stove with boiler supplying gravity-fed water.

 

BTW John, by adding a boiler to the Squirrel it was my intention, not only to provide free heat at the rear of the boat, but also to reduce the excess heat in the vicinity of the stove. I have since decided on a low-tech solution (one that has worked in a house), that is to add extra fire bricks to reduce the internal size of the stove. I'll just have to use shorter logs!

 

Noah

[John Orentas]

Noah.

 

Couldn't agree more about the simplicity thing, I don't have a single radiator, just a woodburning stove on it's own. The discussion was reaally an achedemic one.

 

I have have a revolutionary method of reducing the heat output from the stove, I put less wood in it.

 

John Squeers

Edited October 29, 2004 by John Orentas

[Sam]

Fitting a rad CAN increase the heat output from the stove. The stove will radiate only so much - a direct result of surface area and temperature. The rest of the heat goes up the chimney. A boiler can take some of the heat away.

To prevent boiling, I once had  a domestic system with a large wood-fueled multi-stove, in series with an oil boiler. (The oil boiler was just used to top up in cold weather - or when the stove went out.). Because the heat output of the stove was very high, it could easily boil if the rads were not on, even though there was a 28mm gravity syphon to a hot tank above. I solved this by putting a tank stat on the pipe immediately behind the boiler. If the water got to about 90deg it switched on the pump to dump the heat into the rads.

<{POST_SNAPBACK}>

 

You can get fans which go on top of stoves. These turn by the heat "drifting" upwards from the stove. The fan then spreads the heat around the boat!

 

[Noah]

Hello Sam

 

I've been looking for one of these fans (usually called "Ecofan") to use on my stove at home as well as on the boat. I've seen them in some chandlers and on the web, but I think the cost of £70- £90 is a bit steep. I'm told they help to circulate hot air away from the stove, but there's another reason why I want one - I have a large parrot on board and I'm hoping that a moving fan on the hot stovetop will be scary enough to keep him from getting fried!

 

Noah