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How to best use HS to change heat/cool HVAC modes?

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  • How to best use HS to change heat/cool HVAC modes?

    We have a new house that's pretty well insulated with geo-thermal/forced air HVAC. I generally find leaving the Honeywell (Redlink) thermostats in "Auto" mode never quite gets it right during the month or two bracketing winter. Temp swings day/night can be pretty broad (68F day, 32F night). Similarly humidity can be pretty brutal too.

    I'd like to know if others are using Homeseer in conjunction with weather data or actual outside temp and humidity data to make changes to the heat/cool modes on their thermostats.

    Sure, a simple "it's cold outside, use heat" seems obvious. But there's also the somewhat temperamental nature of the Honeywell web portal. You don't want to poll it "too frequently" else it'll lock out. That and in some situations rooms like a home theater can actually require cooling even when it's cold outside. Lots of people at a party, in/out of the theater room and it gets pretty warm in there.

    So I'd like to know how folks are using HS to come up with an intelligent framework of events to manage this. Thoughts?

  • #2
    I have a very similar setup. We have three ClimateMaster Geothermal Systems which are controlled by Honeywell Prestige IAQ Thermostats (redlink) with Redlink Gateways for Internet access. I also have Aeotec Energy Meters measuring total wattage. To control the system from HomeSeer, get the "Honeywell WiFi Thermostat" plugin made by skWare. Cost is $29.95 and well worth it. Though it says its for "WiFi" thermostats, it will control the Redlink thermostats via the Redlink gateways. I also strongly recommend the "Easy Trigger" plugin as that provides for better daily scheduling. Using Easy Trigger, you can define schedules for each day of the week, and trigger based on whether the time enters or exits particular schedule ranges, or if time is within a schedule's range.

    The Thermostat plugin works by sending data to the Honeywell Comfort Connect Internet site which then sends it back to the Thermostats via the Redlink gateway so there is a few seconds delay between the time you select / change something and the Thermostat changing, of course, everyone would want instantaneous, but I think this is about the best you can do to interface Redlink to HomeSeer. It gets polled about once every 5 minutes to update the corresponding HomeSeer devices and seems pretty reliable. If you are using HomeSeer events to read the temperature, I think they only read from the "local" HomeSeer system and don't necessarily send a query to the Honeywell system. If you are setting a temperature or changing anything else, the plugin responds shortly after you do the set. So when writing events, you don't have to worry about too many reads upsetting the temperamental Honeywell web site.

    Indoor Temperature comes from the IAQ thermostats. For outdoor temperature and Humidity, I've added one of these to my system (you only need one even if you have many zones):

    My home also has Time-Of-Day electric usage with different schedules for Fall/Winter versus Spring Fall and also a peak charge which is a cost multiplier based on the highest total usage during a peak period. I use Aeotec Energy Meters to monitor the homes total energy usage as well in combination with the Easy Trigger schedules to turn off / on zones as the day goes between Peak charge periods and Off-Peak periods. Generally, I turn off 5 zones during Peak leaving on only 1 zone, but if the total power usage is rising fast (e.g., due to electric oven turning on, etc.) I shut down the 6th zone to avoid an excess electric peak surcharge, and restore the zone when total draw lowers and also restore all zones during off peak. If you have this type of metering, I can explain a bit more.
    Last edited by jvm; November 15th, 2018, 11:18 AM.


    • #3
      Here's the Thermostat interface as it shows on HomeSeer:
      Click image for larger version

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      • #4
        Yes, I have that plug-in. It works, most of the time, but I think the reliability has more to do with Honeywell's side of the equation. I also have the Prestige thermostats, along with the outdoor unit (along with two indoor remote sensors to get 'more useful' temp readings).

        I asked out 'here' and not in that plug-in's sub-forum, to try and raise a discussion that might be suitable for more than just one particular thermostat or plug-in.

        I do not currently have that sort of metering option. (Pun intended, heh). But it's interesting to hear that you're combining multiple sensors that way.

        Is your logic able to avoid shutting off heat if temps pass below a certain threshold? That's been one of my concerns about hijacking thermostatic controls. Don't want to have something go wrong and cause pipes to freeze.

        I had an odd-ball situation two summers ago when "something" was causing the mode to be changed to heat and the set point to ambient outside temp. Suffice to say on a 92F outside day that was NOT a good thing to discover for the 2nd floor at 6pm. Geo-thermal is great and all but recovery time can be long if the temp swing is too wide. It wasn't until around 9:30 that evening that it became 'habitable' again! That episode put me off fiddling around with the plug-in. I'm sure it was a combination of factors, some being my own, some being the state of Honeywell's website at the time.

        Our occupancy patterns are pretty stable, so using the schedules on the thermostats has worked well. It's the switching between heat/cool modes that's tedious during the Fall-Winter and Winter-Spring transitions. Thus my hope to come up with a workable scheme that handles changing the modes without unintended complications.


        • #5
          I'm in North Carolina and we usually don't have huge swings within a day so I usually don't have to worry about running Heat and Cooling in the same day. My optimizations are more around peak / non-peak hours, and peak wattage.

          If I were concerned about shutting off heat below a certain temperature, I'd probably address that by setting up a recurring event that goes off every 15 minutes or thereabouts, and at that time, I'd check the outside temperature device and compare it to a threshold, say 40 degrees, and if it is below that, then check the System Modes and turn them to Heat. I think the Easy Trigger plugin is useful for this because you can set your triggers based on simple mathematical expressions.

          In my system, I also have some events that trigger and send email to me if, somehow, the system gets out-of-whack. For example, I have a trigger that goes off every few minutes and if wattage is over 10 Kilowatts, I get a mms message. Consider something like that - i.e., if the outdoor temperature is above a certain level and you're in heat mode, send a message; if the temperature is below a certain level and you're not in heat mode, send a message.


          • #6
            Final thought for switching between schedules for Fall/Winter versus Spring/Summer. My events are based on a Easy Trigger "Current_Peak_Schedule". I also have two additional Easy Trigger schedules defined - one for the fall/winter peak rates, one for the spring/summer. Each day at 12:01 am, I check if the date is between Oct. 1 and March 31. If so, I use Easy Trigger to copy the fall/winder schedule to "Current_Peak_Schedule". Otherwise, another event copies the spring/summer schedule to "Current_Peak_Schedule". This handles the seasonal switchover. It sounds like something similar would work for you.

            Click image for larger version

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            • #7
              I have the Easy Trigger plug-in but have not yet begun to investigate using it.

              I'm thinking some of the ways it allows working with 'virtual' devices/values could be very handy for this and other situations.

              Another being dealing with days where it's overcast enough to necessitate bringing up lights instead of waiting for scheduled intervals.