Netatmo slaves and sniffs away all day

My Netatmo weather station bravely faces the Bangkok morning sun. All day and into the night it toils away collecting data every five minutes even how much CO2 we emit in bed.

Netatmo for sustainable tropical living

Night air conditioning use in a Bangkok condo high-rise. This graphical history represents moderation in air conditioning use over 12 days in August 2016 with a monthly electric bill of about fifty dollars US. Other units in the same building use ten times as much air conditioning. Why?

Temperature data are inside (blue) and outside (red) I turn the air conditioner on near or after midnight for a few hours when we are home and the bedroom temp is 28 or more. Set point is 24 deg C (75 deg F). Turn it off 3 or 4 am. This is what the thrifty Thai do.

Other thermophobic expats in Thailand prefer aircon 24 hours a day, 7 days a week.

Netatmo timestamp conversion to Excel 2011 Mac

This is for Netatmo weather station enthusiasts. It is one of those nuisance problems that caused me to waste a day.

Netatmo data downloads provide a Timestamp for each reading time. It is expressed as Unix time for your time zone (in my case Bangkok), a big number such as 1467025349. Because there has been a lot of messing around with time formats by Microsoft Excel over the years, there are dozens of conflicting formulas out there that are supposed to do this conversion.

I am working with the 2011 Mac version of Excel and after a lot of frustrating attempts finally arrived at a formula that does the conversion that matches Netatmo's conversion shown in the "Timezone: Asia Bangkok" column which for some reason doesn't import into Excel. These are the kind of headaches that make me long for the days of Lotus 123.

Excel date=((Timestamp+25200)/86400)+24107 

With the Timestamp example of 1467025349 this should yield (in Excel date language) 41086.75172 or 6/27/16 18:02.

Netatmo's help facilities are not the greatest when it comes to this kind of thing, so I hope this fills the gap for now.

Global warming: view from the village grandmother

She was already, in Thai terms, an old grandmother when I came the first time here to the village of Bu Hua Chang, fifty years ago this month. The Thai never seem to be very aware of just how old they are, but I make her age to be 91 years. She is a central part of our little neighborhood in the village, sitting in the public space on an ancient wood platform that seems to be reserved for women and children, busy with her little betel nut kit the way old village people have been forever, always a calm and quiet presence in the group of women and kids that sit under a big tamarind tree in our neighborhood. Nim and I enjoy visiting her and take encouragement from her bright conversation, she is twenty to forty years out ahead of us.

I ask her, “Grandmother do you think life was better in the old days or now?” Several of my neighbors are quietly observing this exchange.

“Old days,” she says. After thinking a bit and cutting some new pieces of betel nut.

Bun married a hill tribe man and she still knows the old mountain language, a wife was expected to learn the language of her mother-in-law. Her daughter Pow and great granddaughter Pat live next door to us, our neighbors and friends. The grandchildren pursue successful urban lives in the industrial towns north of Bangkok, accountants or something, leaving the kids back in the village with the old people. It's a good system, the kids learn the old courtesies and graces here, helping their grannies get onto the morning bus to the market in Takhop.

Are there any of the old hill people left?

Auntie Kian in nearby Bahn Takian, is one of them; her husband too, she says.  Nim and I resolve to pay them a visit.

I tell her the story of how my old friend Longmah fifty years ago said that if I ever saw a bear in the forest walking on his hind legs and holding a  tree branch like an umbrella, I should pass with a courteous greeting. Bears think they are the same as people, they have a lot of dignity, and can become quite angry at disrespect.

Yes, she says, they are fiercer than tigers when they are angry. She recalls the time when one of them was harassing the village nightly and everyone was afraid. Her neighbor, an old lady then like herself now, ran out of her house directly at the bear, lifting up her little shirt and flapping her dugs at the bear. 

The bear fled in great fear. Our neighbors respectfully listened to all of this, nodding their heads.

“And Grandmother, I remember there were so many big trees in the forest above the village before we moved the village to build the dam, that was fifty years ago, and there was water in the Lam Pra Plerng River then even in the dry season. I know you remember too.”

She thinks a bit. “Yes, too many people came here, and we cut the trees as if it was the same as the old days, we didn’t know what we were doing.” The Thai have a remarkable capacity for accepting responsibility, blame is less rarely heard. Is blame a western disease? I read of a Thai man who was struck down by a drunk driver but refused to take even insurance money for his medical expenses. He figured it must have been just punishment for his carelessness or past wrongs.

Next time: Grandmother's opinions on global warming

Another Netatmo benefit: use aircon but save energy

Shut down arcon at 3 am causes rise in CO2 in closed
bedroom from about 400 ppm atmospheric to almost 800 ppm

Many people leave air conditioning on all night. The thrifty Thai have a better idea.

Here are the data from last night, you can see that if I turn off the aircon at 3 am the temperature (pink) rises, then accelerates at about 7 am (sun on the sliding glass doors, heating the curtains), so I turn on the aircon again for experimental purposes and leave the room. Meanwhile CO2 (green) accumulates when the aircon is shut down, but falls again with aircon on, reaching atmospheric in about an hour.

Yes, a mystery. Isn't the air handler just circulating room air? Why is the CO2 flushed away with the doors and windows closed? I'm thinking that the intake duct is probably pulling some air from some building cavities that contain CO2-free air.

I enjoy this wonderful Netatmo setup and the CO2 data fluctuations lend themselves to all kinds of interesting experiments.

I've talked to various low-budget Thai people who use aircon sparingly as I do. Turn it on at bedtime when the interior is 29 or more, set to 25 C, and then off in the early hours, switching to a fan, which keeps the temp below 29 for the night. This appears to be optimum for energy conservation if you are ok with 29 which works if you use the fan.