I want to implement a Ready By routine. Some might call it prewarm but my search for “prewarm” here only came up with one not very relevant post and “Ready By” is barely mentioned either. Except here Hive ready by type automations - #2 by Solar2
Hive’s description of the function is: “Ready By will learn how long it takes for your home to heat up. This means the time you set in your schedule should be the time you want it to be warm by and we will get it ready by then.”
An associate tried it before on a Pi based Hive “copy” with a Google calendar and it’s not easy, as the software has to look ahead every say one minute for several hours to see what ON events are coming up. Then work out when to start the boiler and zone valves based on current temperature and the thermal mass of the building. He used a fixed thermal mass, like 4C rise per hour, based on experiment.
I need a 5 hour look ahead but Hive only does 1 hour.
Using the OFFSET option in TRIGGER I guess I can offset the ON events by 5 hours and then add a condition based on prewarm time = (set temperature – current temperature) / thermal mass. THEN at the offset trigger time IF temperature in room is less than set temperature turn ON before the set time by this amount of prewarm time. Needs a separate routine for each zone as the thermal mass will be different; between 30 mins and 5 hours prewarm time in my application. Not seen a Blueprint that includes all this. Is there one?
But Hive is more clever in that it works out this thermal mass based on past history. And if it does it correctly it should reassess the result every month or two ( or continuously) as it varies with the outside temperatures, as external heat losses are higher and wall temperatures are lower in the winter. Anyone tried this with a HA?