VenstarT7900 Colortouch Thermostat with Built in Wifi And Humidity Control (replaces T5900 and ACC0454)

I considered the Honeywell Wifi, Ecobee, and Nest thermostats before buying the Venstar 7900. The Venstar 7900 is effectively the same as the 7850, but adds humidity sensing and control. It is not a "learning" thermostat which was not something I needed with home automation tied in. It's responding to presence and geolocation, so it doesn't need to predict when I'll be home.The reason I went with the Venstar over those other very popular and capable thermostats is the local API. It is a well documented and easy to implement JSON API. Now of course this means programming but even if you're someone who has no idea what these acronyms mean, you will still find this thermostat well designed and intuitive. The Android Venstar app is very well designed and works well (I use Android), their cloud site allows you to control multiple thermostats and even multiple homes like a vacation home, for example.Never heard of Venstar? They are popular in commercial buildings and appear to be part of Bryant/Carrier which you've probably heard of. Not a minor player, and of course many years of experience in HVAC. I think Carrier originally invented air conditioning - could be wrong.If I had to pick nits it would be these:1) The touch screen could be a bit more sensitive. My experience messing with Nest and Ecobee in stores is that they're about on par with a smartphone screen. The Venstar requires just a little more pressure, but consider this: It's a programmable, has an outstanding smart phone app, can be controlled from a website, and has both local and internet API control for home automation integration. I hardly ever actually touch the thermostat itself.2) The t-stat has the ability to display messages for filter changes and such, and also any message you care to send it so long as it is entered in their app or a web interface. There is no way to send it a message in the documented API which is a shame. I'm still trying to figure out the protocol since its obvious the messages from the cloud make it to the device.

I started out with a Honeywell Wi-Fi thermostat for my Florida condo and found that it wasn't capable of controlling humidity. I researched and bought the Venstar which does control humidity. It was easy to install and easy to program and set up alerts and schedules. When I went to a new condo in Florida, I immediately installed one and just installed two in my summer place, too. The instructions are very thorough. Just look for the configuration for the type of heating / cooling you have and it works great. Be sure to pay attention to how to set the micro-switches on the thermostat. Great tip - take a picture of the wiring configuration of the old thermostat you are replacing, before you uninstall that and install this, just in case you have to go back to it.Update: on 9/21, one of my two Venstar T7900s stopped communicating with Wi-Fi after I had to replace my faulty router. The other T7900 communicated flawlessly with the new router. I contacted support by email, which is the only way I could see to contact them. That really works for me rather than a phone call. After several messages and pictures back and forth, it was resolved the same day that they were going to send me a new one. I received it 8 days later and it was a T7850 which does not control humidity. I contacted them again and received the correct T7900 replacement on 10/12. I installed it and it is working perfectly. Very satisfied with my experience with their support group.

I bought this to replace an older custom controller that uses outdoor air when more efficient. I had to pull new wires and add a relay to control the "free cooling" damper. After two days of wiring and installation (yes I am a qualified), the unit works as stated.Update: Originally I downgraded this to 2 Stars because of some interface issues. Well, the issues with the temperature readings and wifi lag are resolved and the unit is working PERFECTLY. In fact, it now controls my ventilator unit that brings in cold air from outside. Highly recommended.ProsGreat color screenGood integration with Weather infoEasy installation instructionsGood designWorks with Fresh Air / Ventilator unit to lower cooling costsGood integration with AlexaCons (reason for 2 stars)App does not have dialog for "free cooling".Main Screen does not have weather. Have to "pull down"I would NOT recommend this product as is.