More Virtual Thermostat questions

[emarquis1]

I want to control a fan (E14) located in the attic to blow warm air from the attic to my enclosed (but not heated) porch.

I have a temperature sensor in the porch (\8) and one in the attic (\1). I also have a temperature setpoint (]40) and will use this to trigger an event action to control the fan.

I want the fan to turn on when the attic temperature is above ]40 but only if the attic temperature is say 4 degrees or more warmer than the porch temperature.

I've tried a few different methods to implement this but can't seem to get it right.

Does the current state of the plugin allow this sort of action?

Thanks,

Ed

[Michael McSharry]

I do something similar with my fireplace where I monitor the delta temp between upstairs and downstairs and turn the blower on if the delta is sufficiently large and the fireplace temp is sufficiently high. I do mine via scripting.

To do it with via the GUI then two things need to occur. One is a delta temperature needs to be satisfied. The second is that the attic temp is above a setpoint. I do not provide a mechanism to do both of these things in one event. Here is what I would do with two events.

1. Periodic Event runs every 60 (or whatever) seconds. Scripts/Speech Scripting text box has the following to set V1 (or whatever) to true or false depending if the 4 degree delta exists between attic and porch.

&hs.SetDeviceStatus "V1", 2 - cint(hs.DeviceValue("\1") < hs.DeviceValue("\8") + 4)

2. Temperature Action Event manual trigger
Select V1 as the Turn On Only When device.
Turn Device E14 and continue until manually turned on or off
On When \1 is above UL, UL = ]40
Off when \1 is below LL, LL = 0 + hs.DeviceString("]40") - 5

In event 1 the device status of V1 will be set to 2=ON or 3=Off depending upon the relationship of the porch and attic with a required delta of 4 degrees. The 4 degrees can be whatever you want

In event 2 the fan ON will only occur when the delta temp is sufficient (V1) and it will start when the temp is above the ]40 setpoint. I selected a 5 degree deadband for the OFF limit, but it can be whatever you want.

I can see where the delta computation would be usefull as a turn on/turn off rather than having only virtual devices in the Temperature Action and this could be done with a single event. Maybe a future change, but either what I sketched out should work or you could just put the logic is a script such as I do. I run my blower fan logic in a 5 minute periodic event.

[emarquis1]

I can see where the delta computation would be useful as a turn on/turn off rather than having only virtual devices in the Temperature Action and this could be done with a single event. Maybe a future change, but either what I sketched out should work or you could just put the logic is a script such as I do. I run my blower fan logic in a 5 minute periodic event.

I tried to use the delta comparison between the attic and porch sensors but it appears to be an absolute value. I wouldn't want to pump cooler air into the porch when it is already hotter than the attic. If delta was a signed value, it would work fine.

I will try your suggestion and see how it does.

Thanks,

Ed