[ANSWERED]: Conditional/Predictive HVAC Setpoints

I have several HVAC schedules throughout a day (akin to a programmable thermostat). These schedules call different action groups to change heat/cool setpoints on thermostats in the auto mode (auto-switchable from heat/cool). So far, no big deal.

What I'd like to do is skip a setpoint action if the absolute outside temperature or outside temperature acceleration (rate-of-change) is within parameters.

For example, say action group will set the cool set point to 73 and I have knowledge of the following data:

• outside temperature is has dropped from 77 to 72 in the last two hours
• inside temperature is currently 74

If these conditions are true, I'd like some predictive behavior and don't want to lower the setpoint. I realize I could do all of this from scripting but it's difficult to modify and maintain with multiple thermostats and multiple actions called from multiple schedules. Then again, maybe I'm missing something and going about this wrong.

[matt (support)]

I assume you've seen the Conditional panel inside the Schedule dialog? If the device state or variable value you need to test isn't available, as I suspect is the case for your first condition but not your second, then I would create a new Indigo variable and additional logic to expose that.

For example, you could create a new Indigo Variable called outsideTempDroppedFast, then create the necessarily logic to set the variable to True/False. Depending on how complex that logic is, you might need to use a script, but by getting the result into an Indigo variable your actual HVAC schedules can just rely on that already calculated data (outsideTempDroppedFast variable value) instead of having to try to calculate it themselves.

I assume you've seen the Conditional panel inside the Schedule dialog?

I guess my problem is that it's getting really messy. The schedule is simply a time then based on some conditions like work, vacation, occupied, etc decides which action group to call.

The action group holds the setpoint values to be updated. To add a lot of environmental conditions there seems counter-intuitive. What seems natural is to alter the action (setpoints) based on environmental parameters. To do this back in the scheduling means that I would have to put all the action group setpoints there too.

I guess I need to think more about this and add something to the wish list. For now I think the best approach is to have each action group execute python code to parameterize the setpoint. That means instead of one process of "environmental parameters", I have to put that in every setpoint setting code for each action group (one for each time schedule) multiplied by action based variables. The attachment is showing logic involved for a single time event and there's at least eight different time events each day. It can be done but if the logic for "environmental parameters" changes, then it has to be changed in twenty-four places instead of just one place.

Are you trying to skip specific thermostat actions (settings) based on the environmental data, or entire action groups? If it's the entire group, then it would make sense to have it as a conditional for the group.

Alternatively, if the specific environmental logic applies to a specific thermostat, independent of the occupancy status, then grouping by thermostat would make more sense.

There's lots of ways to skin this cat, it really depends on how you're trying to apply the logic. It might make even more sense to skip the action groups entirely, and write a python routine that has access to the temp data, time of day, and occupancy status, and returns the correct setpoint for each thermostat.

I assume you've seen the Conditional panel inside the Schedule dialog?

I guess my problem is that it's getting really messy. The schedule is simply a time then based on some conditions like work, vacation, occupied, etc decides which action group to call.

The action group holds the setpoint values to be updated. To add a lot of environmental conditions there seems counter-intuitive. What seems natural is to alter the action (setpoints) based on environmental parameters. To do this back in the scheduling means that I would have to put all the action group setpoints there too.
....etc

Stevemac00,

While this doesn't have the ability yet, if you can give me some ideas of the rules, and the logic. I can look into adding some of this into the Thermostat Enhancement plugin that I write. Right now, it is mainly a monitoring plugin with some override ability.

But, it can certainly be extended to support something like this, if I can work up the logic behind this.

- Ben

Thanks Ben. That's a very nice offer. I'll look into it further.

My desire is to leave as much as possible in Indigo. Otherwise, nobody else could easily change it and I don't want to spend a lot of time making modifications.

But I think I've come with a way where I can keep basic indigo schedules. Replace all the action groups with a single script and get the rules from a spreadsheet file to apply to sensory input. I'll post something as I write it. Maybe there could be some helpful collaboration. But now I'd rather be sailing.

Here's my plan:

1. Use Indigo's scheduling with titles like "HVAC-Morning, etc.
2. Small plug-in which monitors log with a callback to update temperatures. (No concurrent thread.)
3. plug-in starts up and reads spreadsheet of thermostat rows with a header column matching the schedule name.

Now I can use standard indigo scheduling. It's easy to modify all the thermostat setpoints in a simple spreadsheet.

I needed some way of sending a parameter from the schedule to the plug-in to match up the schedule with the spreadsheet.

I started out making a dummy device with the spreadsheet header but I found it's simpler to use the log subscription and it appears safe.

Now a single script handles all the updates and makes some predictive calculations by looking at forecasts, humidity, humidity trends, outside temperatures and outside temperature trends. The plugin will also monitor changes from different zones in the home.

I'm satisfied thanks to indigo extensibility.