Mini-split A/C and Hardwired TStat

[jgreenberg01]

I know this has been discussed before, but my question is a little different.

I am going to add A/C to my garage, and a mini-split is my preference because I'm not sure where I'd put an air handler for a regular unit. Plus mini-splits are cheaper!

While those remotes they include are fine, I also want to control it through HS4. Some of the manufacturers offer "smart" solutions which seems to always require using their proprietary app. Others allow a 3rd party smart wi-fi TStat, but they also require a cloud connection.

This is a new installation so I can use any brand I want, but the manufacturer websites aren't clear on adding a wired TStat.

Yes, I know I can use an IR blaster, but that doesn't provide 2-way communication.

Don't want to go the wi-fi route unless there's one that does not require an internet connection and will integrate with HS4. Another potential issue with wi-fi is the manufacturer messing with their API (like what just happened with MyQ last week that required days to get fixed!).

My preference is to find a way to use a Z-wave TStat like the Honeywell I use to control my Carrier central air unit.

I've also had an A/C contractor over and he's looking onto it for me, but it's been 3 days and no word from him yet.

I suspect that Carrirer or Mitsubishi has some sort of module that let's you hardwire a TStat but I can't find it easily on the interwebs. So before I call their tech support, wait 45 minutes on hold, then try to interpret what someone from another country with marbles in their mouth is mumbling, I thought I would see if anyone here has figured this out already.

Thanks in advance for any help!

[TC1]

I don't believe you can use a traditional wired Tstat made for a regular HVAC or boiler, whereas, there are closed contacts for 24VAC to activate heat, cool, etc. Most Mini-splits use serialized commands, in that when the customer requests let's say "cool" mode it is telling the unit Cool, plus fan speed, plus louver operation, etc.

I've looked into this for my Fujitsu mini-split systems before, the type of solution you are asking for usually requires their hard-wired TStat and their cloud service. I have yet to find anyone who was able to take a non-OEM Tstat and wire it to a mini-split. If you hear otherwise I'm all ears

[Michael McSharry]

mcsMQTT supports the Daikin WiFi protocol locally as well as the WMP protocol used by Intesis. There has been discussion on this message board about Daikin which could help identify specific models that are know to use the Daikin WiFi protocol. Going the Intesis route would be like using a 3rd party (e.g. Next, Honeywell, etc) on a traditional system, but applied to the mini-split. Intesis is not cheap.

[TC1]

Michael is right, the Intesis A/C gateways will get you local control for many brands (check their website) but they are not cheap, usually around >$200 per head unit. Since I have 4 head units I skipped this route and went with one-way control using an IR blaster and the mcsMQTT plugin for one room in my house, and a Remotec A/C IR blaster for another room.

[randy]

I have LG mini splits and they offer an optional dry contact interface for a standard thermostat. I am using the ThinQ plug-in to control mine by HS. The plug-in allows me to control them and reports their change of state if dine by the remote.

[Michael McSharry]

Michael is right, the Intesis A/C gateways will get you local control for many brands (check their website) but they are not cheap, usually around >$200 per head unit. Since I have 4 head units I skipped this route and went with one-way control using an IR blaster and the mcsMQTT plugin for one room in my house, and a Remotec A/C IR blaster for another room.

To be clear mcsMQTT supports a WiFi connection to units that come from the factory that have WiFi Daikin protocol. It also supports the Broadlink IR (RM4 Mini/Pro) for IR control.

[jgreenberg01]

I have LG mini splits and they offer an optional dry contact interface for a standard thermostat. I am using the ThinQ plug-in to control mine by HS. The plug-in allows me to control them and reports their change of state if dine by the remote.

Thanks for that Randy, the dry contact option sounds like it could be a winner!

According to LG's website: the LG Dry Contact for Third Party Thermostat PDRYCB300 "Through a small electronic control module, we now can accept inputs for call for heat/cool, fan and on/off. Additionally the module can have inputs for occupancy sensors and report alarms for specific reasons."

I can use an Aeotec 6-in-one (or similar) sensor to get the temp & humidity, and have HS4 control everything else.

I'm wondering why you chose to use the ThinQ app as opposed to a z-wave TStat. I'm asking because I use LG's app for my refrigerator and I would say it's just OK.

Also, how do you like their mini-split?

[randy]

The ThinQ app is ok, but the ThinQ plug-in gives me full control and real time status updates. There is much more for the AC units on the app than the refrigerator. With the plug-in I can change the air flow, temperature, power, etc. For example, in the bedroom we have the airflow direction cycling vertically and horizontally while cooling the room. When we go to bed, we change the flow to be high and away from the bed. If we use the IR remote to control the unit, the status is reflected in HS. We just installed them this season. We love the units. They are quiet and even more efficient than the mini splits they replaced. The plug-in also reports more for the refrigerator and laundry products than the app.




Here is the refrigerator using the HS4 legacy device page

[mminehan]

We have Fujitsu split units (VRF) that have both a wall controller and IR handheld remotes.

I have tried a couple of options over the years. Remotec ZXT Zwave controllers work but are limited and unreliable. And IR is one way only in that any changes made using the AC wall controller is not detected by the ZXT and in turn not reported to HS.

In the end I forked out for the Intesis units and haven't looked back. Wifi but not cloud based, so all 'in house' control. Responsive and you get full control including all modes, fan speeds and direction control is your unit has that. And this method is turely bi-directional, so HS is aware of any changes made to the AC unit no matter what is used (remote, wall controller etc).

With Michael's mcsMQTT plugin, the 'WMP' protocol that Intesis uses is fully supported. Check the Intesis website to see a list a brands and models of AC are supported.

Just my 2 cents worth.

[ewkearns]

Most of the Internet "knowledge" suggest that you buy the ideal unit for your application and then try to figure out how to control it. I don't know if this will work or not, but they did use the words Trane, Z-Wave, and Mini-split in the same sentence. Here. My HVAC guy says that the control and upkeep of mini-splits are like herding cats, even on the best days. Keep us in the loop, I'm considering the same approach for heat and cool in my workshop.

[TC1]

[QUOTE=ewkearns;n1493188]My HVAC guy says that the control and upkeep of mini-splits are like herding cats, even on the best days./QUOTE]

Slightly off-topic, but yes.
I have a century-old dormered beach bungalow, there is simply no place to put duct-work for a central A/C system, so a mini-split system with a large outdoor compressor feeding multiple heads/zones was the only viable solution to get rid of our multiple window A/C units.

The units are fantastic in terms of noise reduction and security (no longer have half-open windows). The downside is something the sales folks never tell you, no matter how carefully you use them, they will grow mold and dirt inside on the blower wheel and cooling fins. Because they are compactly designed, cleaning them can be an expensive exercise if you hire someone ($250 to $350 per head unit depending on your location). Since I have 4 heads, that's over $1000 a year if I do it annually. Because of that, I decided to invest in the equipment to do it myself (a commercial steam cleaner).

Just a word of caution for anyone contemplating mini-splits.

[jgreenberg01]

Most of the Internet "knowledge" suggest that you buy the ideal unit for your application and then try to figure out how to control it. I don't know if this will work or not, but they did use the words Trane, Z-Wave, and Mini-split in the same sentence. Here. My HVAC guy says that the control and upkeep of mini-splits are like herding cats, even on the best days. Keep us in the loop, I'm considering the same approach for heat and cool in my workshop.

Thank you for that - this is really interesting, although it specifically says it's for the Australia market.

Luckily I sell custom homes and we use Carrier and Trane. I've reached out to our supplier to see if there is a US version of this.

I'll post his response here.

[RRR]

For what is worth... I have a multi-zone LG and use the HS plugin as well. One head unit is in the garage and the other is in the bonus room over the garage. I've setup a serious of events to monitor and control. I also use an external temperature monitor to base events on. I looked at the external thermostat add-ons for LG and just couldn't justify the cost between those and what capability I already had within HS. Just seem like great way to get more value out of HS.

[jgreenberg01]

The ThinQ app is ok, but the ThinQ plug-in gives me full control and real time status updates. There is much more for the AC units on the app than the refrigerator. With the plug-in I can change the air flow, temperature, power, etc. For example, in the bedroom we have the airflow direction cycling vertically and horizontally while cooling the room. When we go to bed, we change the flow to be high and away from the bed. If we use the IR remote to control the unit, the status is reflected in HS. We just installed them this season. We love the units. They are quiet and even more efficient than the mini splits they replaced. The plug-in also reports more for the refrigerator and laundry products than the app.

Here is the refrigerator using the HS4 legacy device page

For what is worth... I have a multi-zone LG and use the HS plugin as well. One head unit is in the garage and the other is in the bonus room over the garage. I've setup a serious of events to monitor and control. I also use an external temperature monitor to base events on. I looked at the external thermostat add-ons for LG and just couldn't justify the cost between those and what capability I already had within HS. Just seem like great way to get more value out of HS.

Question for either/both of you: The LG plug-in looks like it gives a lot of control, but I'm assuming you still need to use LG's cloud-based app - I'm trying to avoid cloud-based device control whenever possible. I'm leery of them because:

• Alexa experiences delays, sometimes long ones, during high-traffic times.
• I gave up on my original zigbee lighting scheme because of intermittent comm blackouts. After switching to Jasco Z-wave switches I have had zero issues.
• Both Alexa & MyQ have actually been down for long periods (long being more than 1 minute), sometimes days because the manufacturer messed with their API.

Having to stand up, walk over to a switch, and press the button when Alexa is bogged down... like Neanderthals used to have to do... is just annoying.

But I want my climate control to be rock-steady, soooo... have you experienced anything like that with the LG ThinQ plug-in?

[randy]

Question for either/both of you: The LG plug-in looks like it gives a lot of control, but I'm assuming you still need to use LG's cloud-based app - I'm trying to avoid cloud-based device control whenever possible. I'm leery of them because:

• Alexa experiences delays, sometimes long ones, during high-traffic times.
• I gave up on my original zigbee lighting scheme because of intermittent comm blackouts. After switching to Jasco Z-wave switches I have had zero issues.
• Both Alexa & MyQ have actually been down for long periods (long being more than 1 minute), sometimes days because the manufacturer messed with their API.

Having to stand up, walk over to a switch, and press the button when Alexa is bogged down... like Neanderthals used to have to do... is just annoying.

But I want my climate control to be rock-steady, soooo... have you experienced anything like that with the LG ThinQ plug-in?

No. My control through the app or HS has been 100% reliable and instant. Not one hiccup. I get a confirmation “ding” fro any of my 5 air handlers the instant I control them from the app or HS.

All that being said, there is always the chance any vendor can changing their API or security verification at any time. I’m reasonably sure the plug-in author is not using a published API.