Quick answer
The right system depends on heat gains, room layout, a route for releasing heat outdoors and permitted building alterations. A portable unit may suit occasional hot days. For regular use, consider a professionally designed split system. Structural alterations in a rented home require the landlord’s written consent.
Assess the apartment before choosing by floor area
On three hot days, record indoor and outdoor temperatures, for example at 07:00, 14:00 and 21:00. Measure indoors in shade and note whether windows and blinds were open. This record helps planning; it is not a prescribed regulatory document.
Record glazing area, orientation, ceiling height, roof position, insulation and heat sources such as computers. A bedroom with evening sun needs a different assessment from a daytime office. Generic watts-per-square-metre figures do not replace room-specific sizing.
Which system suits your use?
| System | Suitable use | Check before buying |
|---|---|---|
| Shading and fan | Occasional hot days | A fan improves how you feel but does not remove heat from the room. |
| Single-hose portable monobloc | Occasional cooling of one room | Window outlet, incoming warm air and operating noise. |
| Portable split | Rooms with a safe outdoor location | Mounting, connection route, weight and condensate drainage. |
| Fixed split | Regular use | Consent, permits, pipe route and noise assessment. |
Reduce heat gains first
Use external shading before the apartment heats up. Ventilate when outdoor air is cooler, where security and noise conditions allow. These measures reduce cooling demand without guaranteeing a particular temperature.
SIA 382/1:2025 addresses mechanical ventilation; SIA 384/4:2025 is also relevant to cooling installations. A standard does not automatically impose a uniform installation ban throughout Switzerland. Required evidence depends on the project and applicable rules.
Prepare your first installer discussion
- Gather a floor plan, ceiling heights, glazing areas and temperature records.
- Send photos of indoor and outdoor locations and the proposed connection route.
- Ask for room-by-room planning when several rooms will have closed doors.
- Ask the municipality about building, energy and noise requirements; clarify landlord or condominium consent separately.
- Request a quote including sizing, drilling, electrical work, condensate drainage and documented commissioning.
Frequently asked questions
Can one indoor unit cool an entire 4.5-room apartment?
It mainly cools its own room. Some cooling may spread through open doors, but this is unreliable for closed rooms. Multiple indoor units or another designed distribution system may be needed.
What does BTU/h mean?
BTU/h measures thermal power. 1,000 BTU/h is approximately 293 watts. Compare cooling capacity in kW with the calculated load, not with electricity consumption.
Find a suitable installer
Search companies by canton and compare services and coverage. Send the same project description to several installers for comparable quotes.
Find companies by cantonSources and scope
For private households in Switzerland. Manufacturer information applies to the named models. Local requirements and system suitability need individual assessment. Sources link to their original language.
- EnergieSchweiz: Raumklimageräte ↗Checked: 2026-10-02
- Schweizerische Eidgenossenschaft: Obligationenrecht Artikel 260a ↗Checked: 2026-10-02
- SIA: SIA 384/4:2025 – Klimakälteanlagen in Gebäuden ↗Checked: 2026-10-30