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Controlling Air Conditioner as Dump Load?

fafrd

Solar Wizard
Joined
Aug 11, 2020
Messages
4,188
I’m looking for ways to control a portable air conditioner as a dump load.

More specifically, I have an Energy Meter that will be measuring when solar power export to grid is approaching my 3.5kW export limit and in that circumstance, I want to remotely turn on a portable A/C (which I have not yet purchased).

I see that there are smart IR controllers that can wake an A/C up out of standby: https://www.iotworlds.com/best-smart-air-conditioner-ir-controller/

So as a worst-case, I figure if I have a portable A/C with IR remote, whether I’m using one of these pre-canned smart A/C solutions or rig up some other home-brewed IR-command-based solution to wake up the A/C, it must be possible to do this.

I’m interested in any solutions members are already using for this, and in particular:

-are there any portable smart A/Cs that can easily be woken up from SmartHome over WiFi?

-are there any any ways to control non-smart portable A/Cs using remote plugs or other Modbus-based solutions?

-what is the easiest way to control a portable A/C using a relay output?

Appreciate any inputs from those that have been down this path before me.
 
I’m looking for ways to control a portable air conditioner as a dump load.

More specifically, I have an Energy Meter that will be measuring when solar power export to grid is approaching my 3.5kW export limit and in that circumstance, I want to remotely turn on a portable A/C (which I have not yet purchased).

I see that there are smart IR controllers that can wake an A/C up out of standby: https://www.iotworlds.com/best-smart-air-conditioner-ir-controller/

So as a worst-case, I figure if I have a portable A/C with IR remote, whether I’m using one of these pre-canned smart A/C solutions or rig up some other home-brewed IR-command-based solution to wake up the A/C, it must be possible to do this.

I’m interested in any solutions members are already using for this, and in particular:

-are there any portable smart A/Cs that can easily be woken up from SmartHome over WiFi?

-are there any any ways to control non-smart portable A/Cs using remote plugs or other Modbus-based solutions?

-what is the easiest way to control a portable A/C using a relay output?

Appreciate any inputs from those that have been down this path before me.
As an example, here is a WiFi-enabled portable A/C: https://www.amazon.com/Portable-Air...s=portable+ac+with+wifi&qid=1668108663&sr=8-3

It says ‘WiFi ready’ but I only see reference to their proprietary app.

Are there are portable A/Cs like this that support an open protocol and which can be controlled by open apps such as Smart Home?

If not, is controlling a smart remote IR controller the easiest way to go and are there any Smart Home integrations for that?
 
one thing to remember is that an AC is only going to run the compressor when its warm, if its 65 outside I can set my AC on its lowest setting and the compressor will not kick on. not sure how reliable in the winter

I use a cielo breeze plus device to control the AC is my workshop via the internet
I have not tried to incorporate into home assistant yet
 
I’ve had my attention devoted elsewhere since getting basic monitoring of battery SoC via sunny island (via Home Assistant) set up, so I wouldn’t profess to be an expert on it. In fact, it sounds like you already know as much as I do!

Unfortunately, I didn’t discover HA until recently, so it wasn’t even a factor when I bought my mr cool mini split and Midea inverter window heat pump AC. Much to my chagrin, my particular brand of ductless mini split is walled off, no API or interconnection possible. Sniffing commands over WiFi is interesting, assuming it’s done in the clear. I’ve only used wireshark a few times, but I could first check connections on the router to see if it’s even capable of connecting via LAN. If cloud, it’ll be encrypted for sure. The Midea isn’t WiFi capable (to my knowledge), so that leaves IR.

IR blaster is an option, certainly, and so too may be investigation of the little usb WiFi adapter. Maybe sniff the usb communications? It’d likely be unencrypted, unlike any cloud connection.

A WiFi socket might be an option, too. I know for a fact that one of my AC units remembers its last state if power is cut off. That one has a heat pump option that falls back to resistive heating if it gets too cold for the compressor. I set up a Smart Home WiFi socket to turn it off automatically when it got too cold for the heat pump, but that WiFi socket got flaky real fast. Guess that relay didn’t like switching with >10 amps load going through it!

one thing to remember is that an AC is only going to run the compressor when its warm
An inverter based AC/heat pump ought to work as a fairly reliable dump load, though… they tend to back off instead of cutting on and off. (Assuming you’d want heat when it’s under 65. I know I would! ?)
 
one thing to remember is that an AC is only going to run the compressor when its warm, if its 65 outside I can set my AC on its lowest setting and the compressor will not kick on. not sure how reliable in the winter
Good point. I was planning to use an A/C battery charger as a dump-load but it suffers from a similar issue: once the battery is fully-charged enough to cause the charger to enter CV mode, you can no longer count on a specific level of power consumption.

If I’m only using the AC because it’s ‘free’ (meaning the energy would otherwise be throttled / wasted), it won’t be an issue.

But if I’m using the A/C as a true dump load to absorb energy that I don’t want exported, I’ll need to rig up a fail-safe dump load or fail safe cut-off (relay( as I’d planned for my battery charger.

Once you are sensing currents and activating relays anyway, that’s nit that big if a deal (just added expense).

But I appreciate the reminder.

I use a cielo breeze plus device to control the AC is my workshop via the internet
I have not tried to incorporate into home assistant yet
Yeah, I’ve seen that device. But by ‘via the internet’ do you mean ‘manually via the internet’ or ‘automatically using their app over the internet’ or do you have a way to control through a 3rd-party app?
 
I have your solution and it only costs $15 and I have been using it to turn on my Living Room AC unit when I am not at home and I see on my Solar App that there is a lot of extra PV power. The unit has it's own App with preprogrammed devices like AC units and it claims that it can learn IR commands.
In my case I just selected Panasonic AC and it worked.


This unit took me a lot of trial and error to find so your really lucky.
 
I’ve had my attention devoted elsewhere since getting basic monitoring of battery SoC via sunny island (via Home Assistant) set up, so I wouldn’t profess to be an expert on it. In fact, it sounds like you already know as much as I do!

Unfortunately, I didn’t discover HA until recently, so it wasn’t even a factor when I bought my mr cool mini split and Midea inverter window heat pump AC. Much to my chagrin, my particular brand of ductless mini split is walled off, no API or interconnection possible. Sniffing commands over WiFi is interesting, assuming it’s done in the clear. I’ve only used wireshark a few times, but I could first check connections on the router to see if it’s even capable of connecting via LAN. If cloud, it’ll be encrypted for sure. The Midea isn’t WiFi capable (to my knowledge), so that leaves IR.

IR blaster is an option, certainly, and so too may be investigation of the little usb WiFi adapter. Maybe sniff the usb communications? It’d likely be unencrypted, unlike any cloud connection.
Exactly the sort of inputs I was hoping for - thanks.
A WiFi socket might be an option, too. I know for a fact that one of my AC units remembers its last state if power is cut off.
A feature like that would make my application trivial to power via relay. I’m prepared to wire up a dedicated circuit/socket for this application and can drive with however big of a relay needed.
That one has a heat pump option that falls back to resistive heating if it gets too cold for the compressor. I set up a Smart Home WiFi socket to turn it off automatically when it got too cold for the heat pump, but that WiFi socket got flaky real fast. Guess that relay didn’t like switching with >10 amps load going through it!
Anything relay-based needs to be smart enough to avoid thrashing, but I can easily plan to cool for several hours at a time to assure I only turn on and off a maximum of one time per day.

Trickier issue for me would be to plan a parallel switch so that the AC can be turned on even when it is not deemed by the energy monitor / controller to be ‘free’…
An inverter based AC/heat pump ought to work as a fairly reliable dump load, though… they tend to back off instead of cutting on and off. (Assuming you’d want heat when it’s under 65. I know I would! ?)
In my case, power generation is only going to saturate during the summer months when it is hottest, so it is exceedingly unlikely I’ll ever want to dump power during cool/cold months…

On the other hand, as I read more about heating/cooling units as well as heat pumps and mini-splits, it’s starting to occur to me that with a unit that heats as well as cools, I could use excess solar generation credits to start to offset a slice of wintertime gas consumption…
 
I use the ceilo app on my phone or tablet to make changes as needed. this is rare because I have set up a schedule on the app
like 7am turn on, set at 72
12 noon turn temp up to 78 for 45 minutes (water heater turn on at noon vis timer, so I turn up the AC)
1245 set tempo at 72
7pm turn off power
 
I have your solution and it only costs $15 and I have been using it to turn on my Living Room AC unit when I am not at home and I see on my Solar App that there is a lot of extra PV power. The unit has it's own App with preprogrammed devices like AC units and it claims that it can learn IR commands.
In my case I just selected Panasonic AC and it worked.


This unit took me a lot of trial and error to find so your really lucky.
Nice!

But can it also be activated by a remote controller such as Home Assistant or a midbus-controlled device or whatever?

Have you only used it with manual control through your phone (remotely or not)?
 
Nice!

But can it also be activated by a remote controller such as Home Assistant or a midbus-controlled device or whatever?

Have you only used it with manual control through your phone (remotely or not)?
Yes I use the App and I can turn on the AC unit from anywhere in the world.
The unit just needs a 5V USB power adapter and then you connect it to your router.
 
Yes I use the App and I can turn on the AC unit from anywhere in the world.
The unit just needs a 5V USB power adapter and then you connect it to your router.
My issue is that I want the control to be automatic either from a Rasberry-Pi-based Energy Monitor or a PLC-based energy monitor (Modbus or relays).

Remote manual control from anywhere in the world is great but not what is needed for use as an automatic / pre-programmed dump-load…
 
My issue is that I want the control to be automatic either from a Rasberry-Pi-based Energy Monitor or a PLC-based energy monitor (Modbus or relays).

Remote manual control from anywhere in the world is great but not what is needed for use as an automatic / pre-programmed dump-load…

If you run Home Assistant on a Raspberry Pi, there's an integration for the IR blaster that @robby linked to.
 
There is a whole group in the Home Assistant group about using Haier and some other branded mini splits and reverse engineering the protocol to use ESPs and ESPhome to control them. One of my minisplits was a Mexican rebrand of a Haier/GE, with a USB port and spoke the same protocol, so for $15, I got 5 ESP8266, and flashed it. Now I can control it from anywhere in the world.

Also, bought another from same company, but with no USB port. I figured it was a premium option, but factory never swapped out the board to differentiate it, just cheaper to use the same board but not include the port. Cracked the head unit open and found RX, TX, GND, and +5V pins. Hooked up to it with the ESP and it started talking. Now this is just the Haier. Quick google search pulls up efforts for Mitsubishi, Pioneer.

This is the link for the Haier mod:
ESP Haier: Haier Air Conditioner + ESP Home + Wemos D1 mini
 
There is a whole group in the Home Assistant group about using Haier and some other branded mini splits and reverse engineering the protocol to use ESPs and ESPhome to control them. One of my minisplits was a Mexican rebrand of a Haier/GE, with a USB port and spoke the same protocol, so for $15, I got 5 ESP8266, and flashed it. Now I can control it from anywhere in the world.

Also, bought another from same company, but with no USB port. I figured it was a premium option, but factory never swapped out the board to differentiate it, just cheaper to use the same board but not include the port. Cracked the head unit open and found RX, TX, GND, and +5V pins. Hooked up to it with the ESP and it started talking. Now this is just the Haier. Quick google search pulls up efforts for Mitsubishi, Pioneer.

This is the link for the Haier mod:
ESP Haier: Haier Air Conditioner + ESP Home + Wemos D1 mini
Cool.

I don't know what ESP and ESPHome are, but I'll look into it.
 
Cool.

I don't know what ESP and ESPHome are, but I'll look into it.
ESP32 is a popular microcontroller. i am assuming ESPHome is software intended to run on said computer type, could be mistaken. regardless, good luck

edit: it seems to indeed be ESP computer software.


 
ESP32 is a popular microcontroller. i am assuming ESPHome is software intended to run on said computer type, could be mistaken. regardless, good luck

edit: it seems to indeed be ESP computer software.


Thanks. I'm currently focused on trying to pull together a PLC-based Modbus controller but after that, I'm mulling the idea of plunging into the world of RasberryPi and an energy management package such as HomeAssistant. Sounds as though ESPHome on ESP32 may be an alternative to that and I'll need to do some research before purchasing a mini-split...
 
I think it's worth noting that you need to respect minimum on and minimum off timers for compressors/ac.

I use water (barrel) heaters as a dump load in a greenhouse during winter and circulator and exhaust fans during summer.

I am careful to lock the dump load on or off for a minimum of 5 minutes. This ensures that any momentary drop in power or voltage doesn't kick the dump load back off too soon.

A controller with minimum on and minimum off timers would be very valuable. I know you've mentioned Modbus and that might be a way to hit the go switch but if you want the bells and whistles something like a BACnet controller has minimum on and minimum off settings for every binary/relay output...
 
I think it's worth noting that you need to respect minimum on and minimum off timers for compressors/ac.

I use water (barrel) heaters as a dump load in a greenhouse during winter and circulator and exhaust fans during summer.

I am careful to lock the dump load on or off for a minimum of 5 minutes. This ensures that any momentary drop in power or voltage doesn't kick the dump load back off too soon.

A controller with minimum on and minimum off timers would be very valuable. I know you've mentioned Modbus and that might be a way to hit the go switch but if you want the bells and whistles something like a BACnet controller has minimum on and minimum off settings for every binary/relay output...
The PLC-based modbus controller I’m working on would allow easy integration of internal timers but I’ll have a look at the capability of a Bacnet controller…

In my case, anytime I have enough energy to run the mini-split, I’d want to keep it on throughout the peak part of the day (meaning several hours).
 
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