In my previous post I described how I got data from my weather station into MATLAB to help me answer my primary questions:
- When to open the windows in the evening, to let in cool air?
- When to close the windows again in the morning?
The data I have available covers 10 days, including a late July heat wave. At first I tried to understand when the lowest outside temperature was reached and when it increased again by more than 0.5 °C and 1 °C compared to the minimum.
|Day||Min Temperature (°C)||Time||Time +0.5°C||Time +1°C|
|18 Jul 2019||16.3||05:54||06:54||06:54|
|19 Jul 2019||17.0||05:56||06:52||07:12|
|20 Jul 2019||20.4||05.56||07:01||08:07|
|21 Jul 2019||20.7||05:45||07:00||07:56|
|22 Jul 2019||19.9||05:56||06:27||07:22|
|23 Jul 2019||20.4||06:14||07:05||08:21|
|24 Jul 2019||21.4||05:53||06:48||07:33|
|25 Jul 2019||22.1||06:16||06:51||07:17|
|26 Jul 2019||22.9||05:42||06:17||07:13|
|27 Jul 2019||23.1||05:50||06:36||07:36|
If I had more data I’d plot a histogram of the times to decide when to close the window in the morning. For now, I can only come up with a “manual estimate” based on looking at the table above. I conclude: During summer I should close the window by 7:30 in order to optimally protect the cool indoor climate.