Guide
Cooling your rental, the legal way
Straight answers on which ACs renters in Germany may install, what's forbidden, and how to stay cool without a permit.
Law & rules
- AC in an Altbau or Listed Building: What Renters Are Allowed to DoOld buildings and heritage protection change the rules for cooling. Here is what you can install without permission, and where the façade is off-limits.
- AC and neighbour law in Germany: noise limits, condensate, and how to avoid disputesHow loud your AC may legally be, where the condensate is allowed to go, and how to keep the peace with the people next door.
- Deducting AC costs: what renters in Germany can actually claimYou can't write off the unit itself, but Germany refunds 20% of the labour cost for installing or servicing an AC in your home. Here is how the § 35a rule works when you rent your flat.
- AC in a Rental Flat: When You Need the Landlord's Consent, and When You Don'tA plain-language guide to German tenancy law: permission-free mobile and window units versus fixed split systems, which need consent, an F-Gas-certified installer and a removal agreement.
- Rent reduction for heat: when it applies and what cools fasterWhat German tenancy law offers when your flat overheats, why deducting too much can backfire, and the permission-free way to get cool this summer.
- Are Portable ACs Allowed in a Rented Flat? Why Mobile Units Need No Landlord ConsentAs a renter, you can just use a mobile monoblock, a window unit or a sealed split. Here is the legal reason no landlord sign-off is needed, and the point where that stops being true.
- Split AC in a Rental: Is It Legal, and How Is It Different From a Permission-Free Mobile Split?A fixed split system and a permission-free mobile split sound similar, but the law treats them very differently. Here is what tenants in Germany can install without asking, and where consent becomes mandatory.
- Can Your Landlord Ban a Portable AC? What Tenants Are Still Allowed to DoWith portable AC units, landlords have far less say than most tenants assume. Here is where your rights end and when consent actually becomes mandatory.
- Which AC Can You Install as a Renter Without Permission?Mobile monoblocks, window units and sealed mobile splits versus fixed split systems: a clear yes/no list for renters in Germany.
- Which Air Conditioners Are Effectively Off-Limits for Renters in GermanyFixed split systems, wall penetrations and F-gas work aren't outright "illegal" for tenants, but three rules make them nearly impossible to install on your own. Here's what actually stops you, and what you're free to use instead.
Devices
- AC on subscription: Grover, miete24 and the Sommer-Abo, honestly comparedThe monthly price is the least interesting number. What counts is how many months you're locked in and who carries the unit back down in October.
- Portable AC Electricity Cost: Realistic Monthly NumbersWhat a portable air conditioner really draws, how to calculate your own bill, and where renters cut costs fastest.
- AC vs Fan vs Evaporative Cooler: What Actually Cools a RoomA fan cools you, not the room. An evaporative cooler only helps when the air is dry. The one device that actually brings the temperature down is an air conditioner. Here's the honest breakdown in degrees, plus what German law allows.
- Can you rent an air conditioner at OBI or Bauhaus?German hardware stores rent drills, not air conditioners. Here are the rental routes that actually exist for Berlin renters, with prices.
- Renting an AC as a private person: your options beyond weekly rates and B2B quotesMost AC rental offers in Germany are built for businesses or lock you in for two years. Here is the decision map for a renter who just wants a cool July.
- Quiet air conditioning for the bedroom: rent, don't gambleDecibel numbers decoded, why the compressor belongs outside your window, and what a quiet season rental costs next to a €1,000 buy.
- Portable AC Without an Exhaust Hose: Does It Actually Cool?No hose, no hole in the window, no hassle: it sounds great but barely cools a room. Here's why, and when an air cooler is still worth buying.
- Renting a mobile split AC: quiet summer cooling instead of roughly €100 a dayOne event company rents these by the day at roughly €100. A whole KlimaLegal season costs about eleven of those days. Here is the maths and what is included.
- Monoblock vs. Fixed Split vs. Mobile Split: Which AC Actually Fits a Renter?The three ways to cool a rented flat work very differently, and only some of them are yours to install without asking. Here's how each one works, what it costs you in comfort and effort, and which type a renter in Germany can actually use.
- Mobile Split Units: Quiet Cooling With the Compressor OutsideThe compressor sits outside and the room stays quiet. Why a mobile split AC needs no drilling and no permit in almost any rented flat.
- How Much Cooling Power (BTU/kW) Does Your Room Need? A Simple Sizing GuideToo small won't cool, too big wastes power. Here's how to find the right BTU or kW rating for your room in a few minutes.
- How Loud Is an AC? Decibel Values ExplainedHow to read decibels: what the spec-sheet number actually means, and when an AC is quiet enough for the bedroom.
Berlin & Brandenburg
- AC delivered and set up for you: the Berlin setup service45.5 kg, two modules, one window bracket. What the "no installer needed" ads leave out, and when the one-off €149 setup service pays for itself.
- Cooling a Berlin Altbau Flat: Why It Overheats and the Legal FixHigh ceilings, big windows, no shading: why Altbau flats turn into heat traps every summer, and which cooling you can legally set up as a renter.
- Renting an air conditioner in Berlin: prices, providers, and what actually works for tenantsNearly every AC rental firm in Berlin serves businesses only. Here are the real numbers for private households, plus what a tenant may legally set up.
- Why Berlin & Brandenburg Flats Get So Hot in Summer (and What Actually Helps)Old GrĂĽnderzeit walls, baking top-floor roofs and a city that stores heat like a stone. Here is why your flat turns into an oven, and the permission-free ways renters can cool it down.
- Cool Your Berlin Apartment Legally, Without Renovation or Landlord FightsSome air conditioners need a landlord's signature and a certified installer. A whole category needs neither. Here's where the legal line actually runs for renters.
Practical
- Cooling a top-floor flat: what actually works for rentersHeat from above, tiny windows, nowhere to store a 30-kilo unit in winter. How to cool a Berlin Dachgeschoss without drilling a single hole, and why renting for the season beats owning under the roof.
- Window Sealing for a Portable AC: The Right Fix per Window TypeA portable air conditioner is only as good as its window seal. Here's which sealing method actually works for tilt-and-turn windows, casements, box windows, balcony doors and skylights.
- Renting an AC at short notice: what you can actually get in a heatwaveThe 24-hour rental firms serve businesses and hardware stores don't hire out ACs. Here is what a renter can still get when the heat is already on.
- What does it cost to rent an air conditioner? All 2026 prices at a glanceSearch results quote anything from €100 to €400 a week. Here are the actual numbers: season subscription, daily hire, buying, and the costs that hide in the small print.
- AC as a Renter: Rent or Buy? Costs, Hassle and Storage ComparedFor renters, price is only half the story. What you're allowed to install, where the thing lives all winter and how much hassle you're taking on all matter too.
- Condensate Water in Mobile ACs: Where It Goes and What to DoEvery portable air conditioner pulls water out of the air. Here is where that condensate ends up, how self-evaporating units handle it, and what to do when the tank fills.
- Sleep Cooler in Summer: How to Use an AC and Cool Your BedroomHonest, practical tips for a cooler bedroom and better sleep in the heat, how to run an AC the right way, and which units renters in Germany can use without a permit.
- Set Up a Mobile AC in 10 Minutes: Step-by-Step, No DrillingNo drill, no landlord paperwork. Unbox a monoblock unit, seal the window, and cool your flat the same day.
- When Is an Air Conditioner Cheapest to Buy? Off-Season vs the Summer Price SpikeThe cheapest moment for an AC is almost never the moment you want one. Here's when prices actually drop, why it happens, and what renters in Germany are allowed to install.