Barbacoa Electrica

Engineer Jansen loves a barbecue. Charcoal, of course. But, here, open fires are FORBIDDEN, and thus charcoal barbecues too. A very old gas barbecue came with the house, but the insides are all rusted beyond repair. 

25 years ago we had an Ilve-Boretti (gas) stove where you could choose two options: an electric barbecue with lava stones, or a fish burner. We chose the fish burner, as burning fishes inside the house seemed more a thing to do than barbecueing. We never used the fish burner, it was just a nice space on the hob to put pans to the side.

Bosch 

What to do. Engineer Jansen is not keen on gas barbecues anyway.  Electric? Searches for Ilve or Boretti did not yield any barbecues. His engineer's eye was caught by a very nice Bosch, model PKU375N14E:

PKU375N14E

And an older model, the PKU375CA1:

PKU375CA1

He quite likes that the heating element is under the lava stones, not on top. So the fat and juices can't directly hit the very hot heating element.

Unfortunately, none are available.  Not second hand either.  That saves us choosing between a PKU375CA1 and a PKU375N14E! 

(Yes, Gaggenau has a similar one too, but we’re not going to pay €1000+ for a barbecue)

TFB4650 

Then this one turned up, the TFB4650:

TFB4650

Only found in Spain. But not in any shop. Unavailable, agotado,  Grmbll.

Wallapop

But, Wallapop, a second hand online shop, like Marktplaats and ebay had this one for €50! "Almost new". Well, for €50 you cannot complain. Ordered it, it arrived promptly, €3,95 delivery cost to the nearest post office. Only disappointment: Wallapop adds €4,40 compulsory "protection" costs to the bill.  

"Nice barbacoa you got there, gov. Shame if something would happen to it.."

You can take the TFB4650 apart:

Take the heating element out, everything else is inox, and could even be cleaned in the dishwasher!

Let's try it out! 

Big advantage is (should be) that  you don't need to light the barbecue. Just switch it on, and it's hot in a few minutes. No preparation, no mess! 

Hm, it's 2100W, so you need to unroll your electric extension cord. Can't leave it rolled up.

No mess

No mess, at all, honestly!

Chicken thigh and courgette, a chorizo, followed by waffles.

Verdict

It's not hot enough. Engineer Jansen expects sizzling and the need for asbestos suits. But, it only just manages to make the chicken skin crispy. The courgette and the waffles are reasonably okay. The chorizo was fine, chorizo needs subtle cooking, no atomic blasting. (There is no photo of the chorizo, as it was devoured before the idea of a photo happened.)

What does get hot (warm) is the electric plug. Apparently 2000W is near extension cables maximum, and also of regular sockets.

Next step: lava stones

The TFB4650 is just a heating element suspended in the air in a metal tin. Not sure if heat is reflected or lost. Lets try adding lava stones. They use them in many barbecues, so there must be a purpose. Maybe they absorb and reflect the heat, diminishing losses.

There is no room between the heater and the grid for lava stones. The stones cannot touch the heater, that will damage the element. It's just a thin metal tube with a coiled heating wire inside.  So, even though Engineer Jansen does not like that, they have to go under. There is sufficient space under the heater. So here goes:

Next try: tomorrow!

Insert 4 - other options

Other options. Usually stand-alone wood stoves, I like soapstone clad, for heat storage. Such wood stoves are also called "nordic", or "swedish" stoves.  These you stoke relatively small fires in, starting in the morning, gradually heating up the heavy stone structure. 200-300-500 kg of soapstone! The heat is released for hours and hours after that. Alas, these are slow stoves, while in the south of Spain the temperature during the day can be quite nice, and you don't need a stove. Only in the evening, when it gets cold you want warmth quickly. Soap stone stoves are not really suited for that. You want a metal stove that can generate heat immediately.  But, these are really beautiful!

These caught my eye in the Attika catalog. But, Attika does not make stoves themselves, they market other manufacturers stoves usually.  

A standalone woodstove would mean removing the existing insert and it’s enclosure in the living room. Quite doable. Not different from installing a new insert, as that requires breaking down part of the enclosure, too. Decisions.

Attika Coluna (fantastic!) made by Hans Greub, CH

Attika Geo (Rais - Denmark)

Heta Scan-Line 40 (Denmark)

Attika ART-10 (Hans Greub, CH)

Hans Greub Furka 2

Hans Greub Combin L

Hans Greub Combin S

Rocal insert 50V (Spain)

Heta Scan-Line 550 insert 5,3kW

Xeoos twinfire Magna (Xeoos, Germany)

The Xeoos is a novel stove, aiming for very efficient and clean burning. You light it, then switch to burning mode. Then what happens is that the burning gases do not go up into the chimney, but DOWN into the bottom compartment, where they burn. Amazing! Look at the website: Xeoos

Insert 3 - Metalfire Optimum 700

Our current old Rocal insert is not very efficient. According to a calculation engineer Jansen found on the internets, so it is true, you need to divide your room's volume in m3 by 14, to find the number of kilowatts necessary for heating. For us that is 9,2kW.  You should add 1kW for every big window, but I did not do that. We're in southern Spain you see.

I wonder if the old insert has that capacity.  I think it's intended more for a "fun" fire, not to seriously heat a room, let alone a house. The heat exchange is at the back and top of the metal box of the stove, where an airflow is maintained by a ventilator.

The rest of the heat escapes through the chimney. Looking for a more elaborate heat exchanger in an insert "Kalfire" was found, and later "Metalfire" from Belgium. Kalfire has a front glass that slides up, Metalfire has a door with a handle.

Here is the schematic for a Metalfire Optimum.   Lots of zig-zag plates that take over the heat from the hot gases:

Three versions:

The first is the plain insert, the second has a "convection mantle",  the third has a block of soapstone for heat storage and slow dissipation for hours.

Enclosure

The insert must be inserted in an enclosure,  like this:

Airflow is by convection only, there is no ventilator. The convection mantle makes installation even easier.

Interior

Interior of the fire chamber can be a combination of Skamol (vermiculite like ceramic material) and metal, and ashpan:

All metal interior

Metal bottom, skamol side and top

All skamol

The metal versions can also be colored, terracotta, gold, ...

See for yourself what versions there are:   https://www.metalfire.eu/en/products/wood-fireplaces/optimum#finishes

They even provide a 3D model, that was immediately incorporated in engineer Jansen's LiveHome3D drawing:

Insert 2 - "rope"

For efficient burning the door of a stove needs to be airtight, air for the fire is only allowed from below the fire, through a grille in the the bottom, and from the top, through an adjustable opening in the top of the door. They make the door airtight by fitting a more or less flexible glassfiber "rope", about 1 cm thick all around the door frame. When you close the door the handle presses the door against the frame, the rope seals off the fire chamber.

You need to replace that rope every few years. If air leaks in, the fire burns a lot quicker, but you will lose a lot of heat through the chimney. Test: a piece of paper between door and frame, close the door, handle thight. If you can pull the paper out easily you need to replace the rope, or fit a thicker one.  It's ot expensive, about 10-15€, including a tube of heat resistant silicone paste to glue it in place, if necessary.

Engineer Jansen bought a kit, and carefully positioned the door on a sheer of cardboard as to not damage anything.Only, when he pressed on the frame to loosen the old rope it turned out that the little brass handle that controls the upper opening was touching the glass. And that cracked. (Damn! Blast! etc)

Down to the local stove shop in Turre, that was open till 14:00, according to their Facebook page. When the engineer arrived there, at 13:40, they were closed from 13:30. (Damn! Blast! etc)

The stove shop in Vera would look in their magazin for the proper size glass. After pressing them a few times they has a slightly bigger glass in stock. But it fit. And cost €100.  (Damn! Blast! etc)

This glass is not glass, but a special ceramic material. No recycling: basura.

Insert 1 - the fire

For heating in winter the house has an insert wood stove and airco. No central heating. Airco is noisy, does not have enough capacity. The wood insert also does not have enough capacity, and also is noisy, as it has a ventilator. It's old. Probably 20 years, as old as the house. So, the vermiculite interior is all cracked, and should be replaced. 

Vermiculite is a quite light ceramic material, "chamotte", that is very heat resistant. You can buy this stuff in plates that you can saw to measure with a woodsaw and files,  or you can buy the proper shapes from the manufacturer. A better, sturdier material is Skamol, but this one just has old crumbling vermiculite. The vermiculite cladding is important, as it insulates the fire chamber, making the temperature higher, resulting in more efficient burning. It also protects the metal interior, and reflects heat into the room.

But, with use it deteriorates and cracks, so after a number of years you need to replace the vermiculite. This insert needs a new interior,  they even put some fire resistant bricks in here to cover the cracks...

A fire is nice though, engineer Jansen can look at the fire all evening. So can the dogs, as you can see below. The only one complaining is engineer De Waal, who would prefer a pellet stove.  However, pellet stoves have more than one ventilator, and are quite noisy. They have a ventilator to blow the fire, and another ventilator to blow the generated heat into the room. Controlled by some electronics these ventilators switch an and off, and are speed controlled, so the pitch also changes, annoying engineer Jansen to no end.

Pellet stoves are very convenient though, no wood chopping, automatic lighting, automatic temperature control etc etc. 

(Will be continued...)

(video)

Papaya and Tex

Coco

Coco

Tex

Vermiculite interior, all cracked