Look for Pump videos, its a bit hidden, but check out the marshmallow shot. First try was just short of worlds record. When I get the new code working I plan on another shot with a metal barrel.
When one of my bathrooms get a makeover I will place a few of these flush with the tiles on critical points like corners or above windows, just for curiosity.
Lot of great ideas here. I have to admit I did not read all the comments. So I hope I am not repeating.
- Heated mirror is a good idea, but I have a simpler one. My mirror is glues to a 18mm partical board or MDF. This board has wholes and that is hung on the wall. I did it so fixtures are not visible. Could be because of the extra mass, but that mirror never fogs up.
- I added an aluminium LED channel in between the tiles in the shower cubicle. And added a LED strip. I think it looks great. You can drive it one of the H801 modules mentioned above. That can run tasmota.
- Also if you can, install a sitting place it the shower. You will thank me later. Best thing in 21st century. You can also install a heating element under the sitting area (I need to warm it up with hot water from the shower).
- Somebody mentioned audio: I would use the small google speaker. You can use node-red-contrib-castv2 to cast speech or audio to that device. So when you turn the lights on, node red can get the weather forcast read out loud for you, or you can cast your local radio station to it.
4a) If you don't like smart speakers, maybe you can do the same with an amp and Google Chromecast Audio and an amp. Way cheaper than Sonos, and probably the castv2 will work as well. - If you will be driving LED lights, I suggest that you switch them from relays that are replaceable. All my lights at the house are controlled by a PLC and each light is turn on by a relay. The relays are replaceable and go into a DIN rail socket in the switchboard. Bathroom gets the most use and I need to replace the relays ever two years or so. The contacts burn together on a closed status and the lights cannot be switched. These damn switch mode power supplies. And I am using Schneider Electric relays not some no-name Chinese stuff.
Good luck for the new project!
Csongor
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One more comment on the LED strip. Initially I was using my Aliexpress, Banggood strips. They all dies in a few months. Than I bought a more expensive one from a local shop. That has silicone coating not the usual resin. Looks and feels the same, but this now runs for 3-4 years without any issues.
Point 5: Perhaps think about solid state relays next time you have to change them. But be aware they donât physically open the line and often a small current can still flow. I personally donât like the clicking sound still noticeable.
Or check if the rating of the relay fit the purpose because failing after 2 years is quite early.
It is a 12A relay. I believe it is about the large initial current draw of switch mode power supplies. There are no such issues on other circuits with fluorescent lamps.
One of many problems LED lights brought into our world. And when you have many switch mode power supplies (as one per downlight) in series the spikes will add up. But tungsten and halogen lamps had the same problem (only pure resistive loads have a factor of 1)
Solid state relays should deal with that because of the short pulse length. But it is always good idea to take a look into the data sheet. For relays I normally choose 16A@230V or higher even when this might look over specified (which light circuit needs 2KW?)
I can't find any documentation that suggests that a relay for switching AC LED lamps needs to have a much higher rating than the LED power rating suggests. They do have a high inrush current but it lasts for a very short time (much shorter than an incandescent lamp for example) and high currents on closing a relay are not normally a problem. Even if you have five 5W lamps, total 25W, that is still only a nominal current of 0.11A at 230V (twice that at 120) so a 10A relay is 80 times over rated.
You've seen how arc welders work then ? long enough to weld relay contacts together 
A LED driver is a switch mode power supply that has specifically been designed to power LED lighting. Like all switch mode power supplies, MEAN WELL LED drivers have an inrush current rating that is shown in the data sheet, typically around 40 to 70 amps and lasting 1 to 2 milliseconds.
And this is not a non name driver. 70 amps sounds enough to do some welding as @dceejay mentioned before. This is perhaps a worst case scenario but one switch event is enough and your relay is doomed. The manufacturers might think why including an inrush current circuit right into the driver when you can sell one extra for a âgoodâ price.
In my opinion the during the quick and massive rollout of LED light fixtures establishing a standard for switching and dimming inside the driver itself was not established. Ok we have dali, knx or dmx but both are too expensive and complicated for home use. Now we have to deal with dimmers designed for incandescent bulbs and deal with that more or less successful in the drivers, for example only to dimm down to approx 20-40%.
From an interior designers point of view halogen lamps where perfect: dimming from 0-100 % and a light temperature âdimmingâ from 2500-3000k comes for free thanks to the physics. Ok you can by fancy bulbs which simulates that but on a chandelier with 10-20 bulbs this will easily cost more than the chandelier alone. And halogen bulbs last a very long time if they are run under 90%. I already have 3 damaged led bulbs (none of them cheep Chinese products) Innovations sometime turns out in a big step backwards and if you are calculating the real CO2 footprint of for example a 10 flame chandelier with halogen bulbs against LED running only a few hours a day and normally slightly dimmed. I do not expect any advantage for the LED not mentioned all the plastic and material mix in an LED bulb compered to mostly two materials: glass and metal in a halogen bulb. But in Germany the politics banned incandescent bulbs so quickly that I canât avoid thinking that the driving factor behind this was not (only) the environment.
Before i forget I have to rush to order a good stock of halogen bulbs before I have do buy them from the local dealer hiding in a dark corner 
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An arc welder works by making a contact and then breaking it to make the arc. A relay will not arc when it closes, unless it bounces open again whilst the inrush is still going on, which should not happen within the couple of milliseconds duration of the inrush.
@Christian-Me thanks for suggesting that manufacturer, I have had a look at one of their datasheets. I see that they do have the inrush current you suggested (60A for 0.5 milliseconds in this case) but I also note that they say you can connect three (or six dependent on the type) to one 16A circuit breaker, which is interesting.
Unfortunately I still haven't managed to find anything specifically relating to the use of relays for driving LED lamps. Also the datasheet for the little blue relays commonly used on Pi expansion boards doesn't mention inrush current. (SRD-05VCDC-SL-C).
When I use light switch replacements I always try to use omron solid state relays. But in most cases I use electronic dimmers wenn suitable and possible. You can get solid state relay boards with optocouplers and indicator led able to be driven with 3.3v logic (VCC 5v) from 1 to 16 circuits and I assume for now that they have not all âfakeâ parts. I then use a I2C port expander and a separate case with short cable too connect it to - in most cases an ESP (raspberries are a little overkill for that task). If anything disastrous happens I loose less than 10âŹ. I spend more money on the case for the high voltage part to protect my home - i had an exploded sonoff POW (1st generation) that made me a little bit less careless. But all these sonoff minis (or similar) are too attractive not to have some of these still in my home.
But to be true I still have more than 20 of this little blue relays around the house and never run into an issue.
I'm no electronics expert but if I've learned anything useful from listening to bigclivedotcom videos, I think that many circuits have inrush limiting circuitry to help with this issue?
I see from a quick search that you can also get high-inrush specific relays (1 2 for example). However, I would have thought that it would generally be sensible to limit the inrush rather than make the poor old relay try to cope with it 
I have to say that my experience is that remote controlled mains switches of any type only last a few years. My LightwaveRF ones are regularly failing now and I've just had the first wifi switch I brought (an EdiMax) fail. Cheap will show through I guess.
In principle, yes; in practice, easier said than done. Relays can be improved greatly by changing the contact materials. The only solutions I've seen for switching power supplies involve either a fixed resistor that uses energy all the time or a thermistor that is expensive and requires a cool-down period. If the fix were simple and cheap, every "wall-wart" would have it, even though most of them are never switched. Whenever possible, I try to do the switching on the low-voltage dc side, rather than on the mains side.
That's the most reliable way to strike an arc, and it keeps on running so that you can use it.
Not likely, but possible. There are conditions where the breakdown field of air can be reached and an arc can exist briefly before contact is made. This is one reason why relays are designed to close as rapidly as reasonably possible. Once arcing has occurred, roughening and oxidation of the contacts promotes more arcing, either on opening or closing.
I measure humidity and Temperature with one sensor (SI70xx on sonoff basic with Tasmota). A humidity change of 10% triggers the ventilation fan to high (low-med-high) by nodered on RPI.
!!! you need to keep track of humidity with a moving averaging node over time, if the actual humidity increases (eg shower) with 10% it will trigger the ventilation (and memorize the trigger value) . This way it will function independent of overall humidity (high in summer, low in winter). Absolute values cannot be used for triggering only changes over (short) time.
The ventilation switches back to normal when it goes below the memorized trigger value.
I used light strips on the wall (top) as indirect light and for the shower area.
Mirrors have integrated lights on each side and a heating element on the back side (switch on/off with the light button of the mirror, could be done with the humidity trigger but this is perhaps an overkill).
Another idea might be a small light(s) triggered by a PIR for nightly visits to the bathroom.
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There is also ready made solutions to cover this. Like for example node-red-contrib-self-adjusting-threshold (node) - Node-RED
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Just on Humidity Sensor...
I have one in the bathroom that turns the fan on. It checks once a minute and if above a specific level it turns the fan on for 10 minutes and off using the timer node.
I have found however the need to compare the bathroom humidity to the general house ambient humidity otherwise on very humid days the fan stays on.
I'm also thinking of add some form of summer/winter adjustment. Fan does not need to be on for as long in the summer.
cheers
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Any chance you could share your flows for this?
