Jump to content
Energy

Lava Slow Combustion fireplace

Recommended Posts

Dear All

Would love some help. Does anyone have experience with this brand 'Lava'. I'm wanting to put one in because they so efficient. Have a look at the attached. 

Sincerely

Jason

Screenshot_20200528-225632_Chrome.jpg

Share this post


Link to post
Share on other sites
Posted (edited)
On 2020/05/28 at 11:03 PM, Energy said:

Does anyone have experience with this brand 'Lava'.

I do not have any experience with the brand but love the sound of my keyboard so will dispense my 2 cents (VAT incl) worth

With regard to the specfic model ("magma") it seems to be an all steel component stove  - including the firebox.  I wonder about the longevity of this (especially the firebox) as opposed to cast iron which I think is more traditional.

The flue/chimney outlet is 130mm - when I had my stove put in it seemed that 150mm flue pipes/fittings etc. were easier to source (is a couple of years back though).

The stove appears to rely mainly (only?) on radiation to distribute heat so I suspect the sides and back could possibly get very hot (relevant for how close other items/furniture etc  can/should be around it). Maybe the natural stone lining will mitigate this (and possibly also prolong the life of the firebox).

replacement availability for the stone liner though? (think stone will over time crack or to some extent erode)

the dimensions (visually) make the ash drawer seem possibly a bit small (not fun if you have to empty it every day or even more than once if burning it for a whole day).

Stove is (at least looks) very low to the floor - if you are married and need practice asking for forgiveness the extra kneeling when adding fuel (for the stove...) is handy, otherwise a stove that is higher might be nicer to run.

No detail on the door handle. Some stoves have a relataively "cool touch" handle - while others require a glove to touch when the stove is going. (same as a cast iron skillet on a stove you WILL forget that glove at least once...)... little kids around.....shoo-shoo

On 2020/05/28 at 11:03 PM, Energy said:

wanting to put one in because they so efficient.

No axe to grind with the manufacturer (even less so seeing that they are local) but with (all) fireplaces/stoves the numbers should be approached with a fairly large pinch of salt (low sodium where possible). I see they quote a max output number but no nominal? How was the number determined? Here I suspect we (in South Africa) are waaayyyy behind the European countries where there are standards for stoves (NRS 097-2 or SANS 10142 for stoves basically...)

In general I will advise

1) like for solar - first determine as accurately as possible what heat capacity you need (it is not that difficult to calculate total area, calculate some R-values/U-values for room material, use google/accuweather to get some historic weather info and calculate expected heat loss to get a sense what you are planning for). Too large a stove (output wise) could actually be worse that too small  - as  far as I know these stoves should not really be operated "choked down" (contributes to soot and creosote buildup in the chimney which has a fire risk).

2) budget for a proper install. Ideally stainless steel flue pipes - double walled AND insulated when entering the ceiling/roof space (relevant to reduce fire risk and helps flue operate optimally). Correct height of the flue (need certain clearances depending of pitch of roof, distance from top of roof, neighbouring big trees etc). The flue is a very big part of what makes these stoves operate well and efficient. Decent flashing (and someone skilled at actually fitting it)  - watching water run down the flue is not as much fun as watching the flames dance..

3) get a good supplier of wood (and then tell no one). Wood must be DRY (like in ideally at least 3 years since first cut). Lots of alien wattle around which burns quite well but to me it seems like bluegum has a greater energy density. Make sure the wood supply will fit in the firebox without touching the sides (logs should actually lie flat on a bed of coals - not the little pyramids that we seem so fond of). (if the stove is running optimally with good dry wood there should be virtually NO smoke visible exiting the flue).

4) look at things like minimum distances advised by the manufacturer from walls etc (peeling paint and cracked plaster - especially behind the stove is not unheard of)

tldnr: no experience of the brand but plenty to say.

Edited by introverter
added info

Share this post


Link to post
Share on other sites
Posted (edited)

Wattle definitely has a higher energy density, but tends to form coals better so is more suited for braai or in a closed stove. For more flames and radiant heat bluegum is better.

Cast iron is better than steel for longevity, and will last decades, but mild steel will burn through in a shorter time. I have a jewel cast iron stove that is ancient and still going, but a similar steel stove collapsed in a pile of rust in about 8 years. 

The best supply of wood is to buy your own chainsaw, and find someone with a bluegum/wattle problem. You can cut a tonne of wood in about 2 hours. Drying takes 3 months minimum. I start cutting winter firewood in Feb/March, so it is now getting fully dry so as to not be too smokey. 

Its best to tile around and behind a fireplace like that as you will get soot on the walls, no matter how good you are at making smoke free fires.

 

Edited by DeepBass9

Share this post


Link to post
Share on other sites

We also use a cast iron stove. 
Because of the hot temperatures with the fire, the steel tend to oxidize (rust) faster. Those steel stoves like this one come with a stone fire chamber. You have to be more careful putting in fuel. For a bit more I would do the cast iron rather. 

About 50% of the cost is the stove. The flue is the other 50%. Go for stainless steel. Anything else you will replace too soon. The part that go through the ceiling will be double walled.

The small ash pan with these closed chamber stoves are not a problem. They burn more efficiently (around 93%) so produce less ash. My stove pan is about 2cm high and take 3-4 nights before it has to be emptied. 

Share this post


Link to post
Share on other sites

Stainless steel flues are very expensive though. I had a galvanised flue running up the outside of the house for years before I replaced it with a stone chimney. When I removed it it only had some light rust where I hadn't painted it. In fact if you have a steel fireplace, the galvanised flues will probably last as long as the fireplace.

Some other things to watch out for if you are not using the fireplace, like in highveld summer, you get condensation forming inside the flue which runs down into the fireplace causing rust spots, so put a container inside to catch that. Also if you spray the inside with Q20 when not being used it helps with rust.

I am looking for that Zebo stove polish which doesn't seem to be made anymore, anyone have a source? 

image.png.6755e2fc82dcb12ece2b83d0c5218d70.png

Share this post


Link to post
Share on other sites
5 minutes ago, DeepBass9 said:

I am looking for that Zebo stove polish which doesn't seem to be made anymore, anyone have a source? 

Don't know about zebo but think this Stove & Grate Polish might be similar if unable to source zebo. 

Share this post


Link to post
Share on other sites
On 2020/05/30 at 1:27 PM, introverter said:

I do not have any experience with the brand but love the sound of my keyboard so will dispense my 2 cents (VAT incl) worth

With regard to the specfic model ("magma") it seems to be an all steel component stove  - including the firebox.  I wonder about the longevity of this (especially the firebox) as opposed to cast iron which I think is more traditional.

The flue/chimney outlet is 130mm - when I had my stove put in it seemed that 150mm flue pipes/fittings etc. were easier to source (is a couple of years back though).

The stove appears to rely mainly (only?) on radiation to distribute heat so I suspect the sides and back could possibly get very hot (relevant for how close other items/furniture etc  can/should be around it). Maybe the natural stone lining will mitigate this (and possibly also prolong the life of the firebox).

replacement availability for the stone liner though? (think stone will over time crack or to some extent erode)

the dimensions (visually) make the ash drawer seem possibly a bit small (not fun if you have to empty it every day or even more than once if burning it for a whole day).

Stove is (at least looks) very low to the floor - if you are married and need practice asking for forgiveness the extra kneeling when adding fuel (for the stove...) is handy, otherwise a stove that is higher might be nicer to run.

No detail on the door handle. Some stoves have a relataively "cool touch" handle - while others require a glove to touch when the stove is going. (same as a cast iron skillet on a stove you WILL forget that glove at least once...)... little kids around.....shoo-shoo

No axe to grind with the manufacturer (even less so seeing that they are local) but with (all) fireplaces/stoves the numbers should be approached with a fairly large pinch of salt (low sodium where possible). I see they quote a max output number but no nominal? How was the number determined? Here I suspect we (in South Africa) are waaayyyy behind the European countries where there are standards for stoves (NRS 097-2 or SANS 10142 for stoves basically...)

In general I will advise

1) like for solar - first determine as accurately as possible what heat capacity you need (it is not that difficult to calculate total area, calculate some R-values/U-values for room material, use google/accuweather to get some historic weather info and calculate expected heat loss to get a sense what you are planning for). Too large a stove (output wise) could actually be worse that too small  - as  far as I know these stoves should not really be operated "choked down" (contributes to soot and creosote buildup in the chimney which has a fire risk).

2) budget for a proper install. Ideally stainless steel flue pipes - double walled AND insulated when entering the ceiling/roof space (relevant to reduce fire risk and helps flue operate optimally). Correct height of the flue (need certain clearances depending of pitch of roof, distance from top of roof, neighbouring big trees etc). The flue is a very big part of what makes these stoves operate well and efficient. Decent flashing (and someone skilled at actually fitting it)  - watching water run down the flue is not as much fun as watching the flames dance..

3) get a good supplier of wood (and then tell no one). Wood must be DRY (like in ideally at least 3 years since first cut). Lots of alien wattle around which burns quite well but to me it seems like bluegum has a greater energy density. Make sure the wood supply will fit in the firebox without touching the sides (logs should actually lie flat on a bed of coals - not the little pyramids that we seem so fond of). (if the stove is running optimally with good dry wood there should be virtually NO smoke visible exiting the flue).

4) look at things like minimum distances advised by the manufacturer from walls etc (peeling paint and cracked plaster - especially behind the stove is not unheard of)

tldnr: no experience of the brand but plenty to say.

Loved this. Wife and I laughed!

Share this post


Link to post
Share on other sites

btw @Energy some things I neglected to mention - these stoves take a bit of time before they are at "running temperature" and if atmospheric conditions are less than ideal (ambient temperature not that cold and perhaps some wind added) they require a bit more tending to to get/keep going nicely  - but when they are going they are fantastic.

something else that none of the overseas forums/info/manual/spec sheets mention is that if you have an alarm system with PIR's in the vicinity of the stove  the PIR will attempt to emulate a strobe light at a rave (people still do that?) onoffonoffonoffonoff...so if the stove is going and you need to pop-out to go buy a mask or bread or head off to bed with the alarm set you may need to bypass the PIR...

Share this post


Link to post
Share on other sites

My PIR points directly at my stove and is armed every night when there are still fire in the stove and it is not a problem. 
I guess it depends on the PIR in use, so you might need to test that.

PS. I added a small 12V fan (120mm PC fan) to the back of my stove (you can put it anyplace) to create a bit of air flow. Man does that make a difference in warming the rest of the house. Just a bit or air movement is all you need.

Share this post


Link to post
Share on other sites
Posted (edited)

I don't have one but apparently you can get thermoelectric fans that you just put on top of the stove and the heat makes them turn. Anyone tried one of those?

fan.jpg

Edited by DeepBass9

Share this post


Link to post
Share on other sites

The cheapest thermal fan I could find (in SA) was R1000 (ouch).
My 12V fan cost me nothing (I used old PC PSU fan and a 12V power supply) and I wanted to test the effect it has on heating the house.

I tried to build my own one of these thermal fans using a Peltier, but that has not worked (yet).

Share this post


Link to post
Share on other sites
16 hours ago, Louisvdw said:

PS. I added a small 12V fan (120mm PC fan) to the back of my stove (you can put it anyplace) to create a bit of air flow. Man does that make a difference in warming the rest of the house. Just a bit or air movement is all you need.

 

14 minutes ago, DeepBass9 said:

I don't have one but apparently you can get thermoelectric fans that you just put on top of the stove and the heat makes them turn. Anyone tried one of those?

Even a little USB desk fan seems to make a difference to circulate the warm air better.  Have not tried the thermoelectric ones but like the idea. Not being able to manually control the speed could be bit of a gamble if the fan air displacement is not matched well to the room size/volume etc?

Other than a sledge hammer, I would not mind an easy solution to get rid of the wall space between a ceiling and a door way (probably has a special name?)... that space creates an upside down dam wall that prevents the warmer air from circulating to more of the house. 

17 hours ago, Louisvdw said:

My PIR points directly at my stove and is armed every night when there are still fire in the stove and it is not a problem. 
I guess it depends on the PIR in use

Maybe my PIR is special 🙂 (It has no problem with a gas heater). In my case the PIR is positioned behind and to the side of the stove which gives it a slightly side-on and looking away from the stove perspective. My theory is that, with the stove producing very noticeable convection of warm air rising and suction of cooler air from a passage area, which both the stove and PIR partially face, quite pronounced thermal turbulence is created that is "seen" by the PIR as a moving heat source. 

Share this post


Link to post
Share on other sites
6 minutes ago, introverter said:

Not being able to manually control the speed could be bit of a gamble if the fan air displacement is not matched well to the room size/volume etc?

Other than a sledge hammer, I would not mind an easy solution to get rid of the wall space between a ceiling and a door way (probably has a special name?)... that space creates an upside down dam wall that prevents the warmer air from circulating to more of the house. 

Those fans do go super fast. The warmer the stove the faster it goes. But a small movement of air makes a huge difference. 
You are moving air(hot) away from the stove, so new air need to take it's place (cooler) which makes the air in the room move transferring to heat throughout the room. 

The problem with different rooms and doors is that the flow stops there. Try adding a fan to move the air say through your hallway and it will make a big difference.

With the airflow in a room moving in any direction (hot -> cold, or cold -> hot), you don't need to move the hot air into a room. You just need to move the cold air out of a room. So a small fan on the floor pushing air out of a room will make hot air flow in above. 

Share this post


Link to post
Share on other sites
3 minutes ago, DeepBass9 said:

Are those fans noisy? I quite like the idea, even just for novelty value if nothing else.

Both are silent (the thermal one, and my home made one).

Share this post


Link to post
Share on other sites
1 hour ago, Louisvdw said:

The problem with different rooms and doors is that the flow stops there.... So a small fan on the floor pushing air out of a room will make hot air flow in above

the fan is worth a try and a much easier "retrofit" than this (actually forgot (some) houses have these) ..

AboveDoor_Window.jpg.f579e42a41eb831e78327eee7ad5317a.jpg

Share this post


Link to post
Share on other sites

Here is a picture of the fan I made. Definitely much cheaper than fitting one of those door windows.
The feet are for better stability but not required. 

The one big problem with it is that it is so quiet that we sometimes forget to unplug it when everyone goes to sleep 🙃, so I was thinking of adding a LED to remind me it is on.

20200608_134518.jpg

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...