Renting an AC at short notice: what you can actually get in a heatwave

Renting an air conditioner at short notice in Germany is, for a private household, close to impossible: the companies advertising 24-hour delivery rent to businesses, not to flats. If a heatwave is already running, your realistic options come down to three: hire a unit by the day from an event equipment company, buy a monoblock the same day at a hardware store, or line up a seasonal rental with lead time for next summer. Below: how fast each route actually is, what it costs in rough numbers, and which enquiries are a waste of a hot afternoon.

Why the 24-hour rental firms won't help you

Search for AC rental in Germany and the results are dominated by industrial cooling specialists, names like Kratschmayer, MJS and Carrier Rental Systems. Nationwide delivery within 24 hours sounds like exactly what you need. It isn't. These firms cool server rooms, production halls and medical practices. Units arrive by truck, often with a refrigeration technician, and pricing runs through individual quotes for commercial clients.

A 16-square-metre bedroom in a Kreuzberg flat is not their market. You can send an enquiry, nobody will stop you. But don't spend the hottest afternoon of the year filling in quote forms priced for factory floors.

There's a simple reason the market looks like this: rental cooling is a commercial business built on large order values. Delivering, setting up and collecting one small unit for three hot days never made economic sense, so a consumer version of the market never developed in Germany.

What does event hire cost?

The one genuine short-term option for private renters is event and party equipment hire. These companies rent mobile monoblock units by the day, around 30 to 80 euros depending on cooling power, usually plus a deposit and either delivery charges or self-collection. For a birthday party or three days of home office at 36 degrees, that's fine.

For a full heatwave the maths turns ugly. Two weeks at day rates lands roughly between 400 and 1,000 euros, for a borrowed machine you collect, connect and return yourself. A monoblock weighs 25 to 35 kilos. Without a car, even the pickup is a project. And here's the catch nobody prints in the quote: when you need one, everyone else has had the same idea. By week two of a heatwave, the hire warehouses are often empty.

Can you rent an AC at Obi or Bauhaus?

No. German hardware stores hire out tools, from lawn scarifiers to demolition hammers, but air conditioners are not part of any rental programme. What they can do is sell you one today. A usable monoblock costs somewhere between 250 and 450 euros, plus a window seal kit for another 20 to 40. Skip the seal and the unit just sucks its own warm exhaust air straight back in.

During a heatwave, that same-day buy is the fastest legal route to a cool room. Two caveats. If the heat has been running for a few days, shelves may be bare, so call ahead. And afterwards you own about 30 kilos of machine that needs a home for the eight months a year it does nothing. Anyone who has hauled a monoblock up four flights of Altbau stairs, no lift, knows that "take it home today" cuts both ways.

The four options, side by side

Here's how the options stack up once you put availability and cost next to each other:

The seasonal rental: for the summer after this one

The fourth option won't fix this heatwave. It fixes the next one. KlimaLegal's Sommer-Abo (Summer Rental) Standard costs 89 euros a month with a four-month minimum term, plus a one-off 189 euros for delivery, setup and collection. That comes to 545 euros for the 2027 season. You get a quiet monoblock sized to your room, the window seal fitted, and no deposit. For bedrooms there's the Premium tier "Leise": a mobile split unit at 199 euros a month plus a one-off 299 euros, 1,095 euros for the season. Two installers mount the compressor outside on a window bracket, so the loud half of the machine hangs outside while you sleep.

The season runs from 1 June to 30 September, and if a unit breaks, a replacement arrives within three working days. Now the honest part: there are only 30 Sommer-Abo slots for 2027, and they can be gone by mid-season. Ask in July at 35 degrees and the answer may well be "fully booked". This is a decision for winter or spring, not for the hottest day of the year.

What to do today, this week, and for next summer

• Today: call your nearest hardware store, ask whether monoblocks are in stock, and have one held. Until then, black out the windows by day and cross-ventilate at night. A fan by the bed helps you fall asleep.
• This week: try event hire companies nearby if you only need to bridge a few days, say until your holiday.
• After a purchase: if you bought your unit through a KlimaLegal partner link and don't fancy the fiddling, the setup service handles installation for a one-off 149 euros. The retailer remains the seller and carries the warranty.
• For summer 2027: secure one of the 30 subscription slots via the waitlist. Delivery, setup and collection are covered by the one-off fee.

Short-notice rental stays the exception for private households in Germany. The hardware store solves today, a seasonal slot solves next June to September. The 30 slots for 2027 go through the waitlist, and once they're gone, they're gone until the year after.