jrainey Posted May 8, 2017 Share Posted May 8, 2017 Here is a simple setup to put a flexible timer system on your bathroom exhaust fan. Hope someone finds it useful. The objective is to let the fan run for a period of time after use, but to ensure that it shuts off in in a reasonable amount of time regardless. The bathroom (in this case our man bathroom) has a fan and a light. They are separately switched with insteon devices. The light switch is pressed into the job of 'occupancy detector' i.e. if the light is on it is assumed that the bathroom is occupied. Goals of the program as as follows: 1) provide a single place to set the timeout value 2) start the timer when the fan is turned off 3) keep the fan running if the light is on 4) shut off the fan after the initial time out (with no light on) OR the full time ot time after the light has been switched off Four programs combine to implement this: 1) MBFanSwON - Executes the timer. Is initiated when the fa is switched on - passes control to a check program when te timeout is reached 2) MBFanCheck - Checks the status of the light and either keeps the fan running or shuts the system down 3) MBLightSwOFF - Resets the timer to allow full run time before shut down 4) MBFanSwOFF - Shuts down the fan and stops the timer. Program 1) MBFanSwON - Main Bathroom Fan Switch On If Control 'BedAndbath / ~Devices / Main Bathroom Fan SW' is switched On Then Wait 10 minutes Run Program 'MBFanCheck' (If) Else - No Actions - (To add one, press 'Action') A timer is started when the fan is turned on. When it times out control is passed to s check program to determine the next action. This program is the central location to change the length of the fan run time - in this case it is set to 10 minutes Program 2) MBFanCheck - Main Bathroom Fan Check - Please take note of the comment that the program must be disabled If Status 'BedAndbath / ~Devices / Main Bathroom Light SW' < 20% Then Run Program 'MBFanSwOFF' (Then Path) Else Run Program 'MBFanSwON' (Then Path) Note that this program must be set to DISABLED. if it isn't it will shut down the fan immediately when the light is turned off. When called by the timer program, the status of the light is checked. if the light is OFF the shut down program is called. If the light is ON the timer program is called again. Program 3) MBLightSwOFF - Main Bathroom Light Switch Off If Control 'BedAndbath / ~Devices / Main Bathroom Light SW' is switched Off And Status 'BedAndbath / ~Devices / Main Bathroom Fan SW' is On Then Stop program 'MBFanSwON' Run Program 'MBFanSwON' (Then Path) Else - No Actions - (To add one, press 'Action') Resets the timer if it is running. Only runs if the light is switched off while the fan is running This avoids starting the timer program if the fan is not running Program 4) MBFanSwOFF - Main Bathroom Fan Switch Off If Status 'BedAndbath / ~Devices / Main Bathroom Fan SW' is Off Then Stop program 'MBFanSwON' Set 'BedAndbath / ~Devices / Main Bathroom Fan SW' Off Else - No Actions - (To add one, press 'Action') The then action is to stop the timer program and shut down the fan. this action is called by turning the switch off or after a time out when the light is either not turned on or turned off when the fan is running. The goal of this is to ensure that the timer program is stopped whenever the fan is stopped. Link to comment
lilyoyo1 Posted June 14, 2017 Share Posted June 14, 2017 Thats a lot of programs for such a simple task. You could simplify it by simply stating if the status of the light is off and the fan is on, wait x amount of time then turn the fan off. Link to comment
jrainey Posted June 30, 2017 Author Share Posted June 30, 2017 Thanks Lilyoyo1. I was under the mistaken impression that once the timer started it would continue to run regardless of subsequent events. (i.e. if the light was turned on after the fan, the fan turn off early). Wrong thinking on my part. The event based programming sometimes confuses me. Link to comment
asbril Posted July 1, 2017 Share Posted July 1, 2017 I also have a simple program for the Fan to go ON for 1 minute when the Light goes OFF. I actually prefer this as the Fan is noisy and interferes with my contemplating the world in the splendid isolation of where King goes by himself....... Link to comment
cyberk Posted July 1, 2017 Share Posted July 1, 2017 I also have my exhaust fans turning on based on humidity levels. The humidity levels are taken from Zwave Multi-sensors. Sent from my iPhone using Tapatalk Link to comment
lilyoyo1 Posted July 7, 2017 Share Posted July 7, 2017 Thanks Lilyoyo1. I was under the mistaken impression that once the timer started it would continue to run regardless of subsequent events. (i.e. if the light was turned on after the fan, the fan turn off early). Wrong thinking on my part. The event based programming sometimes confuses me. You're welcome. I was like that too when I first started with the ISY. I had a million programs just to do one thing. In time, it'll become second nature. Link to comment
larryllix Posted July 7, 2017 Share Posted July 7, 2017 I use dew point to run exhaust fans now. It is more predictive of the desired resultant. I discovered by exhausting air with a higher humidity than the outside air, I may still be increasing the humidity, instead of lowering it, once the incoming air is cooled down to the room temperature. Dew Point comparisons eliminate this and it's easy to calculate. Link to comment
BCreekDave Posted July 9, 2017 Share Posted July 9, 2017 I've got analog sensors wired into an EZIO 2x4 module that auto on-off the fan. Works rock solid for two years running. The relay wall switch for the fan can override for 15 (normal) or 30 (fast on) minute intervals. Sent from my iPhone using Tapatalk Link to comment
builderb Posted July 10, 2017 Share Posted July 10, 2017 I use dew point to run exhaust fans now. It is more predictive of the desired resultant. I discovered by exhausting air with a higher humidity than the outside air, I may still be increasing the humidity, instead of lowering it, once the incoming air is cooled down to the room temperature. Dew Point comparisons eliminate this and it's easy to calculate. Easy to approximate! I set up the formula for my weather station, and the dew point formula was a bit of a puzzle for a while. Granted, I needed to use RPN, but still! dewPoint=243.12,humidity,.01,6.112,17.62,5,9,/,tempF_BME,32,-,*,*,5,9,/,tempF_BME,32,-,*,243.12,+,/,EXP,*,*,*,LOG,*,440.1,-,19.43,humidity,.01,6.112,17.62,5,9,/,tempF_BME,32,-,*,*,5,9,/,tempF_BME,32,-,*,243.12,+,/,EXP,*,*,*,LOG,-,/,1.8,*,32,+ Personally, I just use humidity to shut off my bathroom fans. Lights too. If the humidity is up, someone is in the shower. We don't get excessive outdoor humidity here during the day. Link to comment
larryllix Posted July 10, 2017 Share Posted July 10, 2017 Yeah. Dew point is only necessary where you compare two humidity levels. I calculate mine, dynamically, using ISY programs so Logs are not happenin' there. My usage is my cold cellar running at 10-18C degrees, and if you bring in warmer and lower RH% air, very often you will increase the humidity RH% as the temperature drops. Use SOAP RPN, I do not. To do the work for me, I like my computers. Link to comment
larryllix Posted July 10, 2017 Share Posted July 10, 2017 As a matter of inerest here is how I got around the log usage with ISY. A simple calcualtion of %RH divided by a factor of 5 was offered elsewhere but the curve gets way off at one end of the range. Note how this line has been used as an inline If/Then condition to fudge any humidity over 45% ...Repeat While $Variable > 45 This is to bring dewpoint resultant at that end of the curve, closer to the actual conversion curves . I use three programs like this, for conversion of inside, outside and cold cellar %RH humidities to dewpoint humidity readings. Sync.DewPoint.in - [ID 0128][Parent 0101] If $sHouse.humidity <= 100 Or $sHouse.temperature <= 100 Then $House.dewPoint.scratch2 = 100 $House.dewPoint.scratch2 -= $sHouse.humidity $House.dewPoint.scratch1 = $House.dewPoint.scratch2 Repeat While $House.dewPoint.scratch1 > 45 $House.dewPoint.scratch1 -= 45 $House.dewPoint.scratch1 *= 0.7 $House.dewPoint.scratch2 += $House.dewPoint.scratch1 $House.dewPoint.scratch1 = 0 Repeat 1 times $House.dewPoint.scratch2 /= 5 $House.dewPoint.scratch2 -= $sHouse.temperature $House.dewPoint.scratch2 *= -1 $sHouse.dewPoint.in = $House.dewPoint.scratch2 Else - No Actions - (To add one, press 'Action') Link to comment
jaysmc Posted July 18, 2017 Share Posted July 18, 2017 For my bathroom fan I set up three programs that provide a simple timer that will run the fan for 10 minutes for each time the ON switch is pressed. First I created a STATE variable: sMasterBathFan with an initial value of 0. The first program adds 1 to the state variable each time the on button is pressed: MBA Fan - On - [ID 002C][Parent 002F] If Control 'MBA Exhaust Fan' is switched On Then $sMasterBathFan += 1 Else - No Actions - (To add one, press 'Action') Then a program to zero the variable if the off button is pressed: MBA Fan - Off - [ID 002E][Parent 002F] If Control 'MBA Exhaust Fan' is switched Off Then $sMasterBathFan = 0 Else - No Actions - (To add one, press 'Action') And a control program that will decrement the variable by 1 every 10 minutes and turn the fan off when the variable is 0: MBA Fan - Control - [ID 002D][Parent 002F] If $sMasterBathFan > 0 Then Wait 10 minutes $sMasterBathFan -= 1 Else Set 'MBA Exhaust Fan' Off I do plan on implementing humidity control whenever I get a sensor, but this set of programs work well for now. Link to comment
larryllix Posted July 18, 2017 Share Posted July 18, 2017 Nice! In the original programs you had a 20% detection, and have sinced removed the logic. What was the objective of that dim level? BTW: I define constant Interger variables so that things look like this. (personal preference) If $sMasterBathFan is $cTRUE Then $sMasterBathFan = $cFALSE You can base logic on the state of another program and avoid the variable usage, but I prefer the variable technique myself. You do get 10, 20, 30, 40, 50 minutes with multiple On taps though. You may want to make a limit on that and a cancelling double tap Off too. Link to comment
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