Even 60 years ago in Africa it was normal to have window mounted self contained aircon units which did have a heat option too. We had one in each bedroom in specially knocked out holes, and they ran all night. Loft insulation hadn’t been invented. I think before that we did have a ceiling fan but it wasn’t used because it blew the mosquito nets about. With sealed rooms and aircon you also didn’t need the nets after spraying under the beds for bugs.
There are a few of these window units about but beware most adverts are just cons for fans placed by the window in the picture. Proper ones heat or cool. I think one of thee would be the ideal solution for a workshop and have seen one intended for caravans with just 1KW output, 300W input.