SMART HOME BUTLER · BEDROOM
Eight hours of sleep and still tired? Look at the air
Door shut, two people breathing all night. By morning the carbon dioxide can be four times what it was when you lay down.
The bedroom has the worst air in the house
That sounds odd until you think it through. A bedroom door is usually shut, the window usually shut, and one or two people breathe inside it for eight straight hours. No other room does that.
A living room holds more people, but the door is open, people come and go, and air keeps moving. A bedroom is the only space in the home that is both sealed and occupied for a long stretch.
So carbon dioxide accumulates all night. Waking heavy-headed, unrested, and slow to come round is partly this — not simply a shortage of hours.
This is not the same problem as the living room
When air in the dining room goes off, you notice and can open a window. What makes a bedroom different is that you are asleep. There is no point in the process at which you can react, and you will not remember it either.
So bedroom automation carries a requirement the others do not: it has to be silent. Waking you at 3am to ventilate trades one problem for another. That is why the approach here differs from every other room.
| Method | How well it works | Will it wake you? |
|---|---|---|
| Powered window, small gap | Best — genuine fresh air | A sound as it opens, silent after |
| Fresh-air unit on low | Good, steady and continuous | Barely audible — the ideal |
| Bedroom door ajar | Moderate, dilutes into the rest of the home | Completely silent, and free |
| Circulation fan | Poor — it only stirs, the total does not change | Noisy, and useless here |
| Air purifier | Useless — it cannot filter CO₂ | Noisy, and useless here |
What one night actually looks like
- 22:30
Lights out
620 ppm, comfortable. The system knows you are asleep and switches to night behaviour: slightly relaxed thresholds, much gentler actions.
- 00:10
First time over the line
It reaches 900. The powered window opens a five-centimetre gap, or the fresh-air unit drops to its lowest speed. The movement is small and you do not stir.
- 00:40
Back down
Under 700, so the window closes again. Thirty minutes start to finish, and you have no idea it happened.
- 03:00 and 05:00
Twice more
Three or four cycles across a night is typical. Each is the same small action, pushing the line back into range.
- 07:00
Morning
The room reads 950 rather than 2500. The difference is not in how long you slept but in what you were breathing when you woke.
Four things it takes care of
Sleep quality
High CO₂ affects the proportion of deep sleep. Same eight hours in bed, more recovery on the night with better air.
Clearer mornings
The groggy stretch after waking shortens noticeably. Plenty of people who assume they are simply not morning people are partly describing their bedroom air.
No trade-off
You used to choose between stuffy and warm or fresh and cold. The system finds the balance between the two for you.
Silence
Every action is designed not to wake you. That constraint is the biggest difference between bedroom automation and everywhere else.
Different rooms, different thresholds
| Your situation | Ventilate above | Stop below | Why |
|---|---|---|---|
| Sleeping alone | 1000 | 750 | Slower accumulation, so thresholds can relax |
| Two of you | 900 | 700 | The general case — twice the rate of one person |
| Small room | 850 | 650 | Less volume to dilute into, so step in earlier |
| Baby in the room | 800 | 650 | The most sensitive case; err on the active side |
| Allergies, cannot open windows | 900 | 700 | Same thresholds, but use a fresh-air unit or the door rather than the window |
What you need to have
| What it does | Category in the system | Essential? |
|---|---|---|
| Measure CO₂ | sensor | Yes |
| Some way to ventilate | cover window, or fan unit | Yes |
| Know whether you are asleep | binary_sensor or scene state | Nice to have |
| Outdoor temperature | sensor | Nice to have |
How the whole thing works
Use the ready-made blueprint
The hub ships with 22 tested automation blueprints — think of one as a fill-in-the-blanks form. This uses greenhouse, the same one as the other air quality scenarios; what changes is the numbers and the conditions.
| Field | What it means | Suggested |
|---|---|---|
| Which number to watch | The bedside CO₂ sensor | — |
| Ventilate above | Open the gap or start the unit | 900 |
| Stop below | Close up again | 700 |
| Extra condition | Only while you are asleep | 22:00–07:00 |
| Notifications | Absolutely not — they wake you | Off |
Just say the word
The WOOWTECH hub ships with HA-MCP, so an AI can connect straight into your system and do the work: find the sensor, build the rule, then test it once itself and only report back after confirming the room really does get ventilated in silence.
Prompts you can copy straight out
Every block below can be copied whole, using the button on the right. Pick the one closest to what you want. There is no need to use them all.
There is a CO2 sensor in my bedroom. When it goes above 900 overnight, ventilate the room quietly and stop once it is back under 700. Do not send me any notifications. I am asleep.
I want overnight ventilation for the bedroom. There is a CO2 sensor by the bed, please find that first. Ventilate with the powered bedroom window, opening it about five centimetres and never fully. If there is a fresh-air unit, use that at its lowest speed instead. Start above 900, stop below 700, and only run between 22:00 and 07:00. Turn notifications off completely. Nothing may reach my phone overnight, anything I need to know can wait until morning. Also watch the outdoor temperature. Below 15 degrees, shorten each cycle, or switch to the fresh-air unit rather than opening the window. Once it is built, test it yourself, confirm it really works, then tell me which devices you used.
There is a cot in our bedroom and the baby sleeps with us, so make the ventilation more active. Start at 800 rather than 900, and keep going until it is under 650. Make every movement smaller and slower though: open the window about three centimetres, and rather run longer than open it wide. Keep notifications off.
Please adjust the overnight bedroom ventilation. Mornings still feel stuffy, so bring the threshold down from 900 to 800. Also let it start earlier, from 21:30, because I have been going to bed sooner lately.
Twice lately I have woken up to the sound of a window opening, and I suspect the overnight ventilation is behind it. Pin the times down for me first: which two nights, what time to the minute, and how long the window stayed open each time. If it really was that rule, take it in a quieter direction - slow the motor down, or split one five-centimetre opening into two or three smaller steps. Failing that, leave the window alone during the hours I sleep deepest and lean on the fresh-air unit instead. Go with whichever you judge to be quietest, and list anything else that makes noise overnight so I can look at those too.
Common questions
No powered window — can I just open the door?
An open window means noise and insects
Is the sensor's indicator light too bright?
Do I need one in every bedroom?
How long does the level take to come down?
Do I have to rebuild it to change the thresholds?
A month from now
The fog after waking is shorter. You sleep the same hours, but the mornings feel different.
And across that entire month, ventilation never once woke you up.