This thread has a great amount of detail that’s really helpful. I have a similar question, except it’s a little different in that I’m starting from scratch.
I recently purchased a house with four very small efficiency apartments. The apartments are supplied by a common residential HVAC system. As the landlord, I pay the utilities. The units are very small and each has what appears to be a single 4x12 heating vent (although I need to research this further). I’m looking for ways to minimize my utility costs without sacrificing tenant comfort. As a starting point, I thought about putting in a smart thermostat with time of day controls and a system to monitor temperature in each unit. However, this could quickly start to cost money and I’d like to move in a direction that I could expand into a more capable system.
The total solution that I’m looking for would ideally:
(1) provide remote monitoring and control, via internet (preferably via wifi),
(2) give the ability to install a temperature sensor in each unit and track temperature by unit over time
(3) provide the ability to install a smart vent in each unit and intelligently control the smart vent centrally via programmatic rules
(4) Give ability to link sensors and vents to create HVAC zones (one zone for each unit in this case)
(5) Provide the ability to slightly limit airflow to units without totally shutting off airflow (I wouldn’t want a computer program to decide to shutoff all vents except one then fire up the furnace possibly damage the HVAC system… a system of detecting high pressure at the vent and opening the vent when pressure is high would also be good),
(6) At a minimum, the ability to adjust vent volumes somewhat to maintain constant heat across units,
(7) A simple user interface (web browser with temperature by time of day is ok),
(8) The ability to automatically get all of this to work together to maintain a separate custom temperature schedule in each unit (nice to have),
(9) the ability to slightly reduce heat / cooling to empty units based on motion sensing (nice to have),
(10) booster fans in the vents that can be used to increase airflow at vents that have lower pressure (very nice to have)
(11) the ability to set custom rules around running the blower fan on the HVAC system to redistribute heat is also a great idea
(12) Finally, the solution needs to be reasonably affordable (under $1,000 for everything, preferably under $500), and be sufficiently reliable that I don’t worry about it running on its own a couple miles from my house or constantly need to drive over to tinker with it to get it to work
Thoughts and advice are definitely appreciated.