Home automation field notes All concepts

comfort

Comfort you did not have to ask for

Comfort you did not ask for: an air conditioner that pre-cools for your return, a fan that knows when nobody is watching, and the etiquette of not being annoying about it.

The best comfort automations are the ones you never notice, because the room was already right when you walked into it. That mostly means measuring what a person feels, not what is convenient to measure. The hallway thermostat’s opinion is sincere, detailed, and about the wrong room.

The comfort automations are the ones nobody asked for and everybody would miss. The air conditioner that starts on the way home. The fan that changes speed when the last person leaves the room. None of it is necessary, which is exactly why it has to be done well; a luxury that nags is worse than no luxury at all.

Measure where the person is

A bedroom fan controlled by a sensor in the middle of the room, or worse by a hallway thermostat, will be wrong at the only moment that matters. Putting the reference sensor where the sleeper actually is, beside the pillow, changes the behaviour completely, because that is the air being breathed and the temperature being felt.

Then a few details make it liveable rather than irritating:

Suggest the free option before the expensive one

When it is warm inside and cooler outside, the right answer is usually a window rather than a compressor. A prompt that says so, with both numbers, is a small automation that saves real money.

Temperature alone gives bad advice. A measured evening: outdoors was about a degree cooler, which looks like a clear win. But the outdoor dew point was near saturation, so opening up traded −1 °C for roughly +12 percentage points of humidity, approximately break-even in comfort, and worse for the building. (The +12 is computed at that evening's indoor temperature; the figure moves with it.) Any free-cooling prompt should be dew-point aware, or it will regularly recommend making the place clammy.

Close the loop on your own advice

A system that only ever nags is exhausting. When the recommended action is actually taken (windows opened on opposite sides, a real cross-flow established) say so. Positive confirmation turns a stream of instructions into something closer to a conversation, and it also tells you the advice was physically possible, which is information you would not otherwise get.

The same event means opposite things

A cross-draught while the place is stuffy is exactly what you wanted. The same draught while the air conditioning is running is money going out through the wall. One physical state, two notifications, decided by context. Resist writing two automations that watch the same sensors, they will eventually contradict each other.

Forecast discomfort, not just weather

Sharp barometric pressure changes noticeably affect some people, and the data is already in your weather integration. Computing the expected pressure change over the next several hours and warning about a rapid drop is a genuinely novel thing a home can tell you, nothing else in your life mentions it, and it explains an afternoon that would otherwise be a mystery.

Humidity as maintenance, not comfort

Bathroom humidity staying high long after a shower is not a comfort problem, it is a mould problem with a delay measured in months. A gentle nudge when it stays elevated for half an hour costs nothing and prevents a repair. The same logic applies to a washing machine door left closed on a damp drum.

The etiquette rule underneath all of it: the house may be helpful, but it may not be smug about it.

The test for a comfort automation: would you notice if it stopped? If not, either the sensor is in the wrong place or you have automated something nobody was suffering from.