We have a complex battle here here in our household, even after sorting out the floor heater thermostat programming, and even after sorting out whose comfort level we’re aiming for (my wife’s of course). The real battle in our house now, as the cooling season gets into full swing, is between outside weather, thermal mass, allergies and configurability of thermostats. Summer weather means lots of sun, warm (70-80+ degree) daytimes with cool (50 degree) nights, with mild to low humidity. The goal is to walk the fine line between heating and cooling on multiple systems to keep the right rooms within the 68-72 degree comfort zone.
- Allergies mean that for much of the year, we can’t open windows to mange the temperature.
- Stucco exterior means the outside of the house heats up to well above the ambient temperature, and due to the thermal mass, keeps radiating heat for hours after sunset.
- Stone floors downstairs, with underfloor heating zoned to various living spaces. Once again lots of thermal mass that generally stays cool unless heated.
The control tools:
- Two Ecobee thermostats, upstairs and downstairs to control the forced air HVAC systems with separate natural gas furnaces and AC compressors
- 10 auxiliary Ecobee room sensors to watch temperatures in individual rooms beyond the hallways where the two thermostats reside
- 10 Keen smart vents in the upstairs rooms to fine-tune HVAC airflow. Keen and Ecobee have an integration that allows Keen to use the Ecobee temp sensor and adjust the vents based on temperature goal for that room and occupancy.
- 4 NuHeat/Signature thermostats for the different floor zones. They have both in floor temp sensors and air temp sensors, but each thermostat can only use one sensor for programing at a time, and really only programmable for simple daily schedules with a common Away.
Prior to the new floors and floor heating last summer, I had a good setup going with just the Ecobees and Keen, but adding floor heating has caused new problem and opened up new possibilities. My family loves the floors heated in the AM, but due to the thermal mass that brings the possibility of a warm floors (even if off), fighting with the cooling system on days when the house
Right now, my biggest challenge is figuring out how to program the the floor heat more intelligently so I can take advantage of the floors’ thermal mass. On days when it’s going to stay cool well into the afternoon, I would like to use the floor heating as the the main heating in the AM, but on days when it is going to get warmer than the comfort zone by mid-morning, I would rather leave the floor heating off and use the floor to keep the house cool. Still working on the instrumentation / access to make that work. The Nuheat/Signature has an accessible API, like Ecobee, and the thermostat actually has access to the predicted temperature for my location, but just doesn’t allow that as part of the programming. Hmmmm.
Here’s a summary of the downstairs usage from the Beestat app (just Ecobee data, no NuHeat).
Below is a badly chosen floor heating program for hot day (Family Room)