[OBSOLETE] Whole House Fan Automation

This Beta is for the Whole House Fan feature of my SmartApp, Climate Control Guru.

Whole House Fan Feature Overview

Whole house fans and window/skylights are toggled, taking advantage of daily temperature swings to save energy. It makes use of an inside temperature sensor along with current and forecast conditions from Weather Underground to accurately predict and fully automate when and how much to ventilate.

This feature of Climate Control Guru improves upon the SmartThings app, Whole House Fan, in the following ways:


  • Needs no outside temperature sensor. Temperature is obtained from Weather Underground.
  • Provides maximized savings 24/7/365 without any seasonal adjustments.
  • Heats as well as cools.
  • Automatically prevents overcooling or overheating.
  • Automatically opens windows (can also work with manual windows).
  • Will turn off thermostat while venting.
  • Will shut off fans if smoke is detected.
  • A learning algorithm allows the app to better regulate inside temperatures over time.
  • Optionally incorporates humidity into calculations allowing it to be used in humid climates.
  • Can open window coverings for ventilation without interfering with normal window covering operation.

Required Devices

  • Whole House Fan
  • Inside Temperature Sensor

Optional Devices

  • Windows
  • Window Covering
  • Contact Sensor
  • Humidity Sensor
  • Smoke Detector
  • Thermostat


To run this app you must cut and paste it into the SmartThings IDE as a new project and then publish it to your SmartThings hub from there. The code can be downloaded from here, https://github.com/lawsonautomation/Climate-Control-Guru. Learn more at https://LawsonAutomation.com.


Night Venting and Day Venting Shown Graphically

#Baseline, No Heating or Cooling

This graph shows a time when no heating or cool of any kind was applied. All systems were off.

Note the even sine wave of the inside temperature and that the daily range falls between 69 and 74 degrees F. Inside average and outside average are roughly the same.

#Cooling with a Whole House Fan

This graph shows cooling using only night venting. No AC was used.

Note the rapid drop in slop of the inside temperature line as cool outside air is introduced. Even though outside average temperatures hover around 80 degrees F, the inside average remains around 74 Degrees F, roughly 5 degrees lower.

#Heating with a Whole House Fan

This graphic shows heating using only ventilation. No heater was used.

Note the steep incline of the inside temperature when warm outside air is introduced. Average inside temperature was maintained around 5 degrees F above outside average.


What whole house fan are you useing? I have one but it is a “dumb” switch and hardly ever stayed on the correct time. I was thinking about using one of those zigbee boards from the cree bulbs and arduino to control it but it may be above my current skill level.

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You will, of course, need the SmartThings Hub to run my app. My app does not vary the speed of the fan, so a simple z-wave, zigbee or wifi on/off switch will work. Don’t use a dimmer switch. I like the LINEAR GoControl, WS15Z-1, Zwave Wall Mount Switch. $31 is the lowest price I’ve found for this type of switch. Good luck with your project!

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For those who are unfamiliar with night venting or day venting, I’ve added some graphics generated from temperature measurements taken when using the same technology as the Whole House Fan Automation Feature Beta (see above).

What ever happened to this excellent looking smartapp. It looks like exactly what I need, but all the links are not working.

Hi David,

The code is old and no longer works. I am working on converting it to run on an Amazon Echo. Please look for it there in a few months.

Thanks, Tom

Bummer. I need something for ST. Thanks for the reply though!