Creeping heat shown by Netatmo module station 17th floor condo.

6 am temperatures on Sukhumvit,
Bangkok over the past 10 days

Based on a 50-year stay in Thailand and study of long-term records I have concluded that the dawn (6 am) temperature is the best indicator of hot season discomfort for the coming day. This just broke through the 30 degree C level this Sunday morning, a rare event, for the first time this year, portending some major hot weather during the peak of the hot season over the coming three weeks. (Maximum sun exposure will be this coming Friday but the greatest discomfort arrives a couple of weeks later, unless we have a strong and early onset of rains). Over the past few decades there has been a very fast rise in hot season dawn temperature, 2 degrees since the late 1970s, reflecting both urban heat island effect from pavements etc but also probably an ominous long term land warming throughout Thailand. The consequences of a continuing trend at this rate over the next 20 years are almost unthinkable —  the doom temperature is said to be about 35.

Meanwhile those of us living in our Bangkok condos and apartments must cope with this difficulty. Even now for some, this means full air conditioning 24/7, typically two to four split unit compressors whirring away, 12 hours a day, as much as 50,000 baht a month. For many systems this produces an unpleasant clammy coolness because the on-again, off-again operation of the typically oversized condo units set to temperatures of 25 or less accumulates interior humidity reaching as much as 80 percent or more. Not comfortable!

A moderate amount of adaptation by owners and smart use and scheduling of the machinery can cut this power use and cost by as much as three quarters or more. My own bill for a typical month is less than 1500 baht and our condo is just as comfortable as our neighbors' who have the big bills of 15k baht or more.

Given the current rate of increased warming in the city, this is an excellent time to experiment a bit, both to economize and to set better standard practices for the coming generation who are expanding the use of air conditioning. I will follow up later this week with another post setting forth specific steps aimed at improved comfort at much reduced cost — with continuing use of air conditioning when it is really needed.