Having just arrived in Bangkok for the 6th time this year, all through Don Mueang, I was asked by someone on your site to provide an update after my arrival re the risk of refused entry. On asking the Immigration officer he told me there is no limit by air, until you reach 180 days duration in Thailand. And then it starts a clean slate on 1st January for the calendar year. All of my trips have been for less than the 30 days. I gather from that I could have 10 or 20 trips as long as the time here doesn’t exceed the 180 day total. It may be his interpretation, I don’t know, but he seemed very explicit and certain. Cheers, hope it helps someone.
TLDR : Answer Summary
The user provides an update after arriving in Bangkok, stating that an immigration officer informed them there is no limit on the number of entries by air until a total of 180 days in Thailand is reached. The user emphasizes that trips can be frequent, as long as the total stay does not exceed the 180-day threshold within a calendar year.