Oh, hey, I'm the author! Happy to answer any questions :)
Any reason why you didn't just use ESPHome for the firmware?
It even has a component specifically for the ULN2003 stepper motor driver you were using
Turning a dumb AC unit smart (without losing my security deposit)
111–120 of 176 posts
Re: Turning a dumb AC unit smart (without losing my security deposit)
#112Re: Turning a dumb AC unit smart (without losing my security deposit)
#113OT: I'm looking for some way to control my AC via Infrared. I have a few pretty standard AC units with IR remotes. The ones with a display on it, that just transmit all the settings on the remote via IR on every button press. Some device I can mount in proximity, that controls the AC, but preferably also has a temperature and humidity sensor included.
If you are not averse to an off-the-shelf solution, Broadlink RM4 PRO universal remote will do both IR and 433MHz wireless (records and replays codes). The temperature and humidity sensor which you can plug-in if you need it is sold separately though (Broadlink HTS2).
Re: Turning a dumb AC unit smart (without losing my security deposit)
#114I don't get how so many large buildings in NYC and Beijing (two cities that I've personally visited) use independent little AC units like the PTAC or minisplit types. A couple per apartment, peppered over the outer walls. Engineers intuition says surely a large central unit would be more efficient and effective. Is it because of personal ownership reasons? Counterintuitive physics? Heat dissipation limitations on the…
Not in US, but on top of no room for air ducts, running long copper lines (for both mini split and multi-split units) tends to be expensive (price of copper). You also need to guide condensation out, so either downward piping or (expensive) water pumps everywhere. Installation ends up being more expensive than the AC system.
Re: Turning a dumb AC unit smart (without losing my security deposit)
#115Earlier quoted context omitted.
> HVAC equipment does this with standardized thermostat terminals. yes, they standardize thermostat terminals, but they should allow additional inputs such as a measure of radiant heat entering through the boundary surfaces. I have to change my thermostat far more because it's a sunny day than I need to because of different outdoor temperatures. Bear in mind, I shouldn't have to change my thermostat at all† (except p…
Does the radiant heat not increase the room temperature, thus affecting the indoor temp sensor? Combining that input with outdoor temperature (and whole weather stations) is totally done. Similarly, floor heating systems measure temperature of the radiating element (floor) and room temperature to decide if they switch heating on or off. I generally combine shutters for large windows in controlling the temperature in…
> Does the radiant heat not increase the room temperature, thus affecting the indoor temp sensor? C
Yes but the temperature of the air in your home is only one part of it. The other part is the temperature of the radiant heat.
I always understood that the temperature is measured in the shade, and that the difference between shade/sun on a sunny day can be very significant. A temperature of 22 degrees in the sun would feel like standing in the shade at 30 degrees.
Similarly in your home it could very well be that the air is your house is heated up to 22 degrees by the outside air and radiant heat, but additionally if you're under the radiant sun sitting next to a window it can feel much hotter.
Of course if the temperature meter itself is exposed to the radiant heat, it'll likely measure that directly. But mine for example is mounted under a table in a utility corner and gets virtually no radiant heat. I could mount it next to the window to get exposure to the radiant heat of the sun, but then if I'm sitting further away from the windows in the room I get no radiant heat but the sensor does, and it'll think the room is a lot hotter than the experience I'm having.
Re: Turning a dumb AC unit smart (without losing my security deposit)
#116I don't get how so many large buildings in NYC and Beijing (two cities that I've personally visited) use independent little AC units like the PTAC or minisplit types. A couple per apartment, peppered over the outer walls. Engineers intuition says surely a large central unit would be more efficient and effective. Is it because of personal ownership reasons? Counterintuitive physics? Heat dissipation limitations on the…
I had the option to buy a “central” unit or several mini splits for my apartment. I chose several mini splits. The main reason is that they can fail independently, so I’m not stuck in an apartment that is hot everywhere. But I think the main reason is that in places without central AC, people tend to want to incrementally upgrade. For example, you might get a mini split just for your bedroom, because that’s the room…
I went with a multi-split central AC: despite the higher cost, it is generally a usability mess.
You can only run one mode for all rooms, and while that sounds reasonable, I have one tiny storage room that houses my old dual Xeon heater, which requires AC on even in the winter.
Re: Turning a dumb AC unit smart (without losing my security deposit)
#117Earlier quoted context omitted.
I wish lock-in was as taboo as medieval Christian attitudes towards usury.
But weren't medieval Christian attitudes towards usury a good thing?
Well, whether is was good isn't really a yes-or-no answer, especially when it got tied together with religious persecution.
I don't think I'd like to reintroduce it exactly as it was, but it's a useful example because:
1. It demonstrates how a strong economic-norm can arise from popular concern that a certain "buyer/borrower beware" arrangement is too prone to abuse.
2. Being unusual to us, it's easier to see and consider, as opposed to existing norms we may take for granted as "just how things are."
3. Since it changed over time (albeit by going away) it indicates that change is possible, and shows those economic rules are socially-constructed.
Re: Turning a dumb AC unit smart (without losing my security deposit)
#118Earlier quoted context omitted.
Exactly. I don't want a "smart" washer / dryer / fridge / toaster. I want a standard interface I can build my own system around, or use someone else's that they've already built.
I wish lock-in was as taboo as medieval Christian attitudes towards usury.
Not minmaxing rent-seeking behavior and vendor lock is a taboo in our contemporary late stage capitalism society
Re: Turning a dumb AC unit smart (without losing my security deposit)
#119I turned mine smart by using an esp32, an IR led and a n ir demodulator. The esp32 has the ir led pointed towards the AC and the receiver aimed at the room. It then hosts a small html page and connects via wifi to my home network. It used the receiver to sync its internal state, if the actual remote controller was used.
Re: Turning a dumb AC unit smart (without losing my security deposit)
#120> Imprecisely yeet the stepper motor all the way left/right, toggling the target temp between “really really hot” or “really really cold” > Option 2 certainly is the “jankier” of the two options, given that it relies on a second-order property (target temp) to power the unit on/off… but hey - whatever’s easier, right? Isn't this basically how a thermostat works? I.e. there is a component that is binary on/off, and a…
For the purpose of cooling, just setting the thermostat to its hottest setting would be in effect "off" just about all of the time. Depending on the design/temperature range of the thermostat, this isn't 100% though. If you want to be able to do both heating and cooling, it'd get a bit complicated since the above would be inverted for heating.
Thermostats often have mechanisms at the top and/or bottom that force the switch to be on or off.