It’s that time of year once again, when the mercury rises and I am reminded of how the air conditioner in my home office is so critical to comfort and productivity. This is a little story of how I recently enhanced the now nine-year-old master of cool.
The Fujitsu Halcyon ductless mini-split air conditioner installed here is one of the larger models they make. It’s rated for 30,000 BTU (2.5T if you prefer) which is quite large for the 400 square foot office. It was sized to accommodate a full-height rack of broadcast equipment that used to occupy a corner in my office.
Back when it was installed, it was enough that it did the basics. It kept the space cool and dry, without being noisy. It meets those requirements even today.
With no controls on the device itself, it’s operated using a simple IR cordless remote control. The remote functions are very basic; on/off, target temperature, mode (cool, dry, auto) and control of the motorized vanes that direct air flow. I hardly had to use the remote control beyond on/off. Since it’s an IR remote, it only works when pointed directly at the indoor unit.
I can’t fault the Fujitsu air conditioner, since it’s installation we have become more sophisticated users. We’ve had a Nest thermostat installed in the house for years. We’ve become accustomed to the ability to program a schedule of temperature changes to minimize energy use. We also appreciate remote control from our smart phones, whether we’re home or elsewhere. This leaves the mini-split feeling primitive and costly to run.
A few weeks ago I discovered Sensibo Sky, a small IoT device that adds all the remote control flexibility of a Nest thermostat to a split ductless unit with IR remote control. It’s similar to the Logitech Harmony remote control scheme, in that it emulates the IR emitter of the original remote, connecting it to our Wi-Fi, and making it accessible via the web and smart phone apps.
Originally priced at $149, Sensibo Sky initially seemed a bit pricey. I found a recent offer of $99 with free shipping too good to pass up, so I bought one.
Installation and setup was very quick and easy. The device needs to be mounted where the air conditioner will “see” the IR emitter hidden in the top. Practically, that means anywhere within view. The device has a small bit of double-sided foam tape on the back, making it easy to mount in on the wall just below the air conditioner, which is near ceiling level in my office.
The Sensibo device is powered via a micro USB port hidden on the back. It comes with a small AC power adapter and a 3-foot micro-USB cable. It needs to be mounted close to an outlet.
The white and black interface device and white power cord definitely make their presence known on the forest green wall of my office.
The software setup process is not entirely unique;
- Install the Sensibo app to your phone
- Power-up the device which will initially act as a Wi-Fi hotspot
- Connect the phone to the Sensibo’s Wi-Fi network
- Run the Sensibo app.
- The app will use info already on the phone to configure the Sensibo device to connect to your household Wi-Fi network.
There’s an alternate process should you need to manually configure the device’s Wi-Fi access.
Once the Sensibo device was on my Wi-fI, I had to add my air conditioner and teach the Sensibo Sky about it. The Sensibo device learns the make and model of the A/C unit by decoding a sample of a command from the manufacturer’s IR remote control. It correctly identified the Fujitsu unit, and was thereafter able to control its various functions.
Time from opening the box to controlling the air conditioner…under 30 minutes.
My site, being a home office, has just one air conditioner. The Sensibo system is able to control multiple air conditioners, collecting them into groups, which may correspond to different locations.
This is consistent with how I observed mini-split air conditioners in commercial applications in the UK. When I worked for Pixel Power I would occasionally visit their headquarters/factory in Cambridge. In that building, each room has a mini-split AC inside unit, piped to its own exterior unit on the rooftop. This gave each room its own temperature control.
In such an installation, a Sensibo Sky device would be installed in each room, giving the entire installation centralized control and scheduling. What a great way to conserve energy.
Further, a company with multiple locations could have managed, system-wide remote control and scheduling.
Sensibo sells their kits with 1 to 4 interface devices. Additional devices can be added after-the-fact.
The Sensibo app itself has all the remote control features I’ve come to expect from Nest, as shown in the various screen shots. The current temperature and humidity is plainly indicated, along with the status of the air conditioner.
At present, I have two daily scheduled events; (1) Set temperature to 73F at 7:30am and (2) set temperature to 78F at 9:00pm. In the summary menu these are shortened to “Turn On” and “Turn off” but they’re actually change in target temperature. It would be folly to have the unit truly turn off overnight during a Houston summer. We currently only drop to about 80F overnight.
At the outset, I had the show notification on my phone when these events occur. I may defeat that notification since it appears that it’s very reliable.
We are an Amazon Echo household. Using the Amazon Alexa app I installed the Sensibo skill and I had the system seek all the smart house devices. It found the Sensibo device right away. As a result, we can now control the office air conditioner by voice.
This can be a little convoluted. It’s important to name devices in a manner that will be intuitive when issuing commands. Since “air conditioner” causes Nest perk up and control the household AC unit, I had to call the device in Sensibo the “office air conditioner” so it would be differentiated.
The Sensibo Sky device has its own temperature and humidity sensors. So a command to change the temperature setting reaches out to the Fujitsu unit. Telling Alexa to, “ask the office air conditioner about the temperature” returns its local opinion of the temperature at the east wall, directly under the AC unit.
Integration with IFTTT is also possible, but I’m not using them much anymore.
So far, so good
I appreciate the fact that we have more consistent remote control of both air conditioners. I also like the ability to vary the temperature on a scheduled basis, even if it’s not exactly clear that it will generate significant energy savings. It will take a few months to see if there’s any real reduction in energy usage.