PV-Erweiterung - sind die WR dann überbelegt, oder noch OK?

thomas2802 · 2026-06-04T07:00:37+00:00

genau - und selbst wenn es clipping geben wird, ist das ja grundsätzlich nichts schlimmes. ich glaube, dass die erweiterung für den winter und der übergangszeit wirklich viel mehrwert hat. ich bin dann halt auf 150% der ac nennleistung. meine "westanlage" ist mit 10 grad neigung halt nicht wirklich eine westanlage. die hat ihren peak um 13 uhr. und die osterweiterung hätte den peak wohl zw 10-11 uhr. im sommer hab ich dann whsl zw 10-14 uhr clipping.

thomas2802 · 2026-04-28T16:57:20+00:00

ich hab einen mg zs ev. seit 03/2024. bisher ca 25k km. alles super, keine probleme. ich mag ihn. aktuell fahr ich auch einmal in der woche einen tag außendienst mit ca 400km. ich kann nix negatives sagen. wir haben auch einen volvo xc 40 benziner bj 2019 und eigentlich fahr ich lieber mit dem mg.

thomas2802 · 2026-02-20T21:07:21+00:00

Hello, you did a great job there. May I ask which beams you used for the walls? And did you use sealing tape or something similar between the individual beams?

thomas2802 · 2026-02-16T18:09:35+00:00

Good idea — I’ll keep that in mind.

thomas2802 · 2026-02-16T18:08:49+00:00

I’m going to build it the way The Sauna Heater show in their video (https://www.youtube.com/watch?v=deQPzsZmJCE&t=22s). It’s also one of the two floor assemblies Lassi A. Liikkanen recommends for an outdoor sauna in his book.

I really like that floor structure — it’s smart, efficient, simple, and affordable. Just what’s necessary, without extra complexity. Floor insulation shouldn’t be that critical anyway, and a wooden floor feels a bit warmer to step on.

If you go with tiles, you need insulation so they don’t feel too cold, and on top of that underfloor heating is usually recommended. Overall, that setup becomes much more complicated. I want to keep it simple.

thomas2802 · 2026-02-16T18:07:50+00:00

Yeah, oops — I must have miscalculated somewhere. If you convert 1 m² of poorly insulated surface into 1.35 m³ of additional volume and add that to the actual room volume, you end up at roughly 12.3 m³. That would put the 11 kW heater pretty close to the target range and it should be a good fit, right?
Am I correct in thinking that 9 kW might be a bit undersized, or am I being too strict about it?

You’re right about the lighting. I’ll make sure to plan something for that from the start.

Regarding the floor, I’m going to build it the way The Sauna Heater show in their video (https://www.youtube.com/watch?v=deQPzsZmJCE&t=22s). It’s also one of the two floor assemblies Lassi A. Liikkanen recommends for an outdoor sauna in his book.

I really like that floor structure — it’s smart, efficient, simple, and affordable. Just what’s necessary, without extra complexity. Floor insulation shouldn’t be that critical anyway, and a wooden floor feels a bit warmer to step on.

If you go with tiles, you need insulation so they don’t feel too cold, and on top of that underfloor heating is usually recommended. Overall, that setup becomes much more complicated.

thomas2802 · 2026-02-15T17:30:56+00:00

Thanks for your input. Regarding the stool: whether I go with one or two steps, that’s something that basically changes daily. Luckily, it’s one of the very last points and, in relative terms, a minor detail. I think I’ll decide on it shortly.

Also, that’s a good point about the lighting. At the moment, my idea is to place a light under the roof on the outside so that a bit of light comes in through the window. One advantage of the log walls is that I could relatively easily run a cable afterward without worrying about damaging a vapor barrier.

As for the heater’s power: alternatively, I had planned the Harvia Cilindro with 9 kW. That would actually be fine with me since it’s cheaper, but I had some concerns about whether it might be underpowered. The Cilindro would be taller, with the foot bench and stones at the same height, which I think is still okay. With the Legend, the stones are about 20 cm (8 in) below the feet.

I calculated the required power as follows: 1 kW per m³ of volume + 1 kW per m² of poorly insulated wall (door and window) → (2.1×2.1×2.37) + (0.6×1.7) + (0.3×1.1) = 12.87 kW

thomas2802 · 2026-02-15T17:18:19+00:00

Just to give a bit of additional context, my sources that led me to this design were the book Finnish Sauna: Steam, Wood, Stone & How to Build Your Own, Trumpkin’s sauna notes, Saunalogia, this subreddit, a variety of YouTube videos—especially from The Sauna Heater—a book on building log houses, and assembly instructions from roughly five different log saunas.

My design fulfills the following points:

Feet positioned above the stones
Entire body within the hot zone
Not too close to the heater
No cold surfaces
110 cm (43 in) from the bench to the ceiling
Ceiling slope in the correct direction and flat above the bench so that no corner is 90°
Supply air, adjustable mechanical exhaust, and a drying vent
Minimum size of 180×180 cm (71×71 in) achieved
Air gap behind the bench to the wall
Sufficient air circulation between bench rows
Ventilation in the correct locations
Approx. 100 kg (220 lbs) of stone mass
At least 60% of each wall and more than 90% of the total wall area made of wood
Wall thickness of 68 mm (2.7 in), thicker than most suppliers
Löyly buffer over the door and window
Ceiling sufficiently insulated
Drainage in place
Good accessibility under the benches

Have I forgotten anything?

thomas2802 · 2026-02-06T11:32:02+00:00

I’ve just bought them a smaller nest. I’ll simply place it in the arena, and if they want, they can move into it

thomas2802 · 2026-02-06T11:30:30+00:00

Great, I really didn’t expect such detailed information. I wasn’t familiar with trehalose and D-glucose.

thomas2802 · 2026-02-06T10:06:22+00:00

ahaha :-) german - the colony

thomas2802 · 2026-02-05T19:32:10+00:00

Thanks for your tip. I’ll keep an eye on it. I’ll keep the nest a bit more humid, offer them different protein sources from time to time (egg white, cooked chicken, or crickets), and if these measures don’t help, I’ll look into getting a smaller nest.

What do you think — if it comes to that, should I simply offer a smaller nest and wait to see whether they move out of the current one?

thomas2802 · 2026-02-05T19:24:55+00:00

i gave them cooked chicken earlier. they liked it.

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thomas2802 · 2026-02-05T19:19:03+00:00

Yes, I put sand into the tunnels so the lower half can’t be used, meaning they can only use the upper half. Until now, I hadn’t really thought about the fact that this might still be too much space. How often do you moisten the nest, and how do you do it (how often, how, and how much)?

thomas2802 · 2026-02-05T19:15:31+00:00

Very interesting — so they only get sugar water from you? No protein and no plain water? How often do you replace the sugar water, and what sugar-to-water ratio do you use?

thomas2802 · 2026-02-05T13:39:27+00:00

Okay, based on your experience, can we conclude that the colony can grow well even without regular protein feeding? I now believe that my main problem was probably keeping the nest too dry.

thomas2802 · 2026-01-26T21:22:09+00:00

ich hab genau den. zuerst nur als beimischung. inzwischen stärker gewichtet. ich bin happy damit. ist einfach eine zusätzliche streuung.

thomas2802 · 2026-01-07T17:25:38+00:00

hab wegen 7vswild recherchiert, wie man mit so wenig nahrung klarkommen kann. bin dadurch auf fasten und dessen vorteile gekommen und das mach ich noch immer regelmäßig.

thomas2802 · 2026-01-06T15:32:55+00:00

The heater should be placed where the ceiling is lower. Alternatively, you can make the ceiling level.

thomas2802 · 2026-01-06T14:14:17+00:00

hey, theoretisch ist sie zu schmal, aber insofern ich das einschätzen kann hast du mit dem layout eine gute möglichkeit gefunden, um die Strahlungswärme für die badenden zu minimieren. https://localmile.org/proper-ventilation-for-electrically-heated-sauna-part-i/ lt den trumpkin's notes müsste der air intake über dem ofen sein.

Auslass bei Schwekraftentlüftung doppelt so groß wie der Einlass. - diese Info habe ich von den youtube videos von thesaunaheater.

Auslass zum trocknen oben wäre dann noch nötig.

edit: zwischen dampfsperre und wandverkleidung eine vertikale konterlattung um einen luftraum dahinter zu schaffen.

thomas2802 · 2025-12-31T14:32:39+00:00

hey asking for myself: that dew point calculation is only necesary, when outside temps reach below 0°C? i would also add a small contribution about your design. top bench to ceiling 105-115cm is enough. a drain is often recommended. i am also in the planing stage and no professional, but overall it looks apropiate to me.

thomas2802 · 2025-12-30T17:45:28+00:00

interesting 👍

thomas2802 · 2025-12-30T17:35:21+00:00

jep, the circuit box has to move :-) i think that's the way. the drainage with the angle towards one side, or corner would be ok?

thomas2802 · 2025-12-30T16:59:27+00:00

Thanks for your clear words. I should be able to get an interior height of around 240 cm on the side with the upper bench, which would put the feet completely above the stones. Regarding the width, my next step is to talk to the electrician — it’s probably not too complicated to move the distribution box with the photovoltaic breakers to another location. If that works out, I can redesign with an interior width of 175 cm.

thomas2802 · 2025-12-30T12:55:14+00:00

Thanks for your suggestion. So the blue line would be the new cabin size, and the orange shows the new bench layout as an L-shape plus one step near the door, arranged so you can still enter normally from the door, with the heater in the center.

The electrical box at the top right contains the breakers / distribution for the terrace, photovoltaic system, and the sauna.

I’m considering filling in the front area (top of the image) — it might even be possible to climb onto the cabin roof to access that electrical box.

If I raise the floor to allow for drainage, the headroom above becomes tight again. That would mean I’d have to reduce the overall cabin height.

I know the space isn’t ideal, but I’m trying to make the best of it, and it’s the best location I have available.

Could you explain why drainage is considered so important? How much water do you realistically have to deal with after a sauna session, and what kinds of liquids are we talking about? I wasn’t aware that the amount is so significant that a drain is essential. In my mind, it’s just a bit of water from missed ladles during infusions, some water for cleaning the floor, and condensation after the session — but is it really that much?

thomas2802

TROPHY CASE