I honestly wouldn't know how to work in this summer without that portable AC of mine... Yes, it costs power. But I only run it when I'm working, only in the office, only to a 25°C target, and it's the most climate friendly option I could find back in 2019 too (R290).


Really happy about an efficiency improvement today! Took the Flir One & scanned my setup for heat creep. Turns out the outlet is fairly well isolated, but the hose turned out to be leaking some air & also radiating heat. Duct tape + blanket ftw! Achieving 10+°C difference now!

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And thanks to everyone who pushed me in the direction of a dual hose conversion again. I'm still not convinced I can make that work in my room & window layout, but considering the heat & energy prices these days I'm going to give it my hardest try. Wish me luck.

Definitely consider this (accidental*) dip to 23.4°C with an outside temperature at 34.5°C (measured on the north facing front) my biggest win of today! 😊

* Why accidental? Too low target temperature set 😬 Doesn't exclusively happen with 3d printers 😅

New backplate for the AC to convert it to a dual hose setup, all parts printed over the last few days and now epoxying together. Thankfully did not have to design this myself, someone already did and shared 👍😊 thingiverse.com/thing:5421906

Just hope it really fits 😅

After just now disassembling the backplate and comparing things directly I'm very optimistic that it will indeed fit 😊

And the new window adapter plate is making progress, almost done, just needs some sealing on top and a coat of varnish 👍

Next step is weather proofing the outlet setup. So I just got to work on the balcony (last chance for the week to use it, will turn into an oven tomorrow again thanks to the heat), sanding and putting the first coat of varnish on the board.

End result, including some sealing tape on top for a better seal against the shutter. Currently doing a first test run (with the 2nd hose just fiddled through the opening due to lack of an adapter). It was very tough to fiddle two hoses through the limited space, but I won!

Currently the two ports are very close together, so to reduce the likelihood of sucking in the exhaust air the plan is to print two redirection thingies that slot into the little rail there in front of the ports, to direct the airflow to opposite sides.

Will have the added benefit of being able to throw some mosquito netting on those covers to keep insects and debris out of the intake and exhaust. The intake already has got netting on the backplate, but I'd also like to keep the hose clear as I store that inside when not in use.

@foosel Oh that's cool! A Graphana dashboard of temperatures around your house?!

How are you collecting the data? Do you have any device recommendations?

@tim I really need to write a blog post about my home automation setup 😅

I have a Home Assistance instance running that interfaces with some self built sensor hardware (ESP8266 + BME680, powered by ESP Home) as well as off the shelf stuff (mostly Zigbee based Aqara multi sensors via Zigbee2MQTT). HA then pushes various data into an InfluxDB from which I then graph it via Grafana. Below is a screenshot of the whole environment dashboard.

@foosel That is incredibly cool! Maybe one day I'll attempt to build something like this!

@foosel @tim zigbee interface connected to a PI 4's Serial/GPIO pins. Zigbee2mqtt & rabbitmq.

Gave up on the standard stuff so got my own code written in go handling most of the automation although zigbee2mqtt does handle some scenes.

Yes, you need to write a blog post. ;-)
I'd be very curious as I'm working on similar monitoring since quite some time, with a moderate number of T-Sensors talking to an Arduino, but my gnuplot does not look that cool...

How do you measure power consumption, BTW? - some modern meter with uplink or reflective sensor on analog meter?

@ceha @tim I monitor it individually with power monitoring capable smart plugs flashed with Tasmota. I sadly have no easy to monitor overall consumption (renter with ancient meter in the public basement), so I'm slowly building up device specific monitoring instead.

Data flows into Home Assistant via MQTT, from there into InfluxDB and then gets visualised in Grafana.

@tim @foosel she's not the only one. Only got the zigbee sensors logging currently.

Got to look at sorting the hot room's temp at some point

@foosel Eigentlich ziemlich schlau und kam bisher in meinen Gedanken nicht vor: Man kann ja den Rolladen mitverwenden.
Der hat ein viel angenehmer quadratisches Format als eine angelehnt Tür. 🙂

@lakoja Jup, und das funktioniert hervorragend! Ich hab vor dem Rolladen dann auch noch immer einen Sonnenschirm stehen, und mache innen die Tür soweit zu wie möglich und dichte den Bereich mit dem Vorhang ab. Laut Wärmebildkamera funktioniert dieser Ansatz wirklich gut.

@foosel Stupid question maybe, but why two ducts? Isn't it "just" heat exhaust? Wouldn't one duct be enough for it?
Pardon me please, I don't know much about A/Cs except they are basically heat-exchangers 🙂

@blindcoder Not a stupid question at all! This article sums it up better than I ever could: woolie.co.uk/article/convert-a

But to give a quick tldr, single hose units use inside air for the heat exchange and then pump it outside. That creates a pressure differential in the room that causes hot air from outside of it to be sucked into it. Dual hose setups separate the outside air loop from the inside air loop, which increases efficiency by a lot.

@foosel @blindcoder I wonder why most ACs are still produced without this option. It's not only stupid. Sometimes it's also dangergous and forbidden (for example in cases you are using gas heaters) because of lowering the pressure in the apartment making it possible to suck back exhaust gases.

@foosel @blindcoder did this kind of mod 2 years ago (with plywood and duct tape on the AC, hoses up converted to 150mm, 2 airduct silencers and a 50W support ductfan, including a full size "window replacement" from polyresin fibre)
still working great.
against the hot outlet and 35 degrees inlet, stone fibre/whool with aluminum coating helps a lot better than any household fabrics.

@foosel Wow, that's some new information to keep in mind, thank you!
Seems my unit can not be converted non-destructively as the entire backplate (including the control panel) is a single piece. Next time I buy one I'll definately check if it's convertible, or comes with two hoses from the start!

@foosel With those pics and your description, in my mind there even pops up another hose on the inlet side which would make it possible to get the inlet air from the coolest part of the balcony...... but yeah, that's probably very superfluos.. just redirecting the wam exhaust air upwards and away from the door will actually already create some updraft in the surrounding air, helping the inlet to possibly catch cooler air on it's own.......

Just my two cents .... erm, glass of wine.. ;)

Nice job!! ;)

@hackbyte You know, that just have me an idea ^^ I just averted a clog of doom earlier tonight, and have some stuff in the queue that beds to be done first, but then I might just look into a custom two sided adapter for the window port, given that I have a couple meters of spare hose

@foosel That looks so much better than my improvised solution with a styrofoam box strapped to the unit!

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