A Monoblock AC Is Only as Good as Its Window Seal

I moved this February. New city, new apartment, top floor of a building that went up sometime in the 1970s, in the Rheinebene, which for the non-Germans reading this is one of the warmest and most reliably sticky regions in the country. The flat is rented, which matters more than it sounds like it should, and I work from home with a dedicated office. Come the first proper heat of June, that office is the problem child of the whole apartment: small, under the roof, and facing the sun. Air conditioning is still uncommon in German homes. Only a minority of households have any at all, and a fixed split system, the efficient kind with the compressor bolted to an outside wall, is essentially off the table when you rent: it needs a hole through the facade and a landlord who says yes. So like a lot of people in this situation, I ended up with the compromise nobody is proud of: a single-hose portable unit. A “monoblock”. Mine is a DeLonghi PAC EL 112 CST, the “Pinguino”, an 11,000 BTU/h…