Portable vs Split AC for a Prague Summer
Every June, the same question comes up across the expat and rental scene in the center: is it worth installing a proper split unit, or does a portable AC from the nearest electronics store solve the problem well enough? Both work. The honest answer depends on how long you're staying, what your lease actually allows, and how much a bad night's sleep is worth to you.
Noise
This is the difference people notice first and complain about most. A portable unit keeps its compressor inside the room with you, which means the loudest part of the whole system sits a few meters from your desk or your bed. Even a "quiet" portable model is noticeably louder than a split system, where the compressor sits outside and only the indoor fan unit runs in the room. If you work from home or you're sensitive to noise at night, this alone is often enough to settle the decision.
Cost
Portable units win on upfront price and simplicity - no installation, no waiting for an appointment, no conversation with a landlord. But they're also less efficient, so running one through a full Prague summer costs more in electricity than a split system would to produce the same cooling, and a budget portable unit rarely lasts more than a few seasons of daily summer use. A split system costs more upfront, including installation, but it runs more efficiently and lasts years rather than seasons. If you're staying in the same place for more than a summer or two, the split system is usually cheaper over time, not just more comfortable.
Effectiveness
This is where portable units struggle most in the center. They vent hot air out through a hose in a cracked-open window, which also lets some of that heat straight back in - and in a top-floor apartment under a hot roof, or a room that gets full sun in the afternoon, a portable unit often can't keep up no matter how long it runs. A properly sized split system is rated for the room and actually delivers the cooling on the label. If your space is small, shaded, and you only need it for a few weeks, portable can be enough. For anything bigger, sunnier, or under the roof, it usually isn't.
What landlords and SVJ boards typically allow
A portable unit generally needs no permission at all - it plugs in and the window hose is temporary. The one thing worth checking is your lease's position on window fixtures; some older buildings restrict anything attached to a historic window frame, even a slim hose bracket.
A split system is a bigger conversation. It needs sign-off from your landlord at minimum, and if the outdoor unit goes anywhere visible from a courtyard or facade, the building's SVJ - the owners' association - usually has a say too, since it affects the exterior of a building they're jointly responsible for. None of this is a reason to avoid a split system; it's simply a conversation to have early, before a moving-in date is fixed, rather than after installation day arrives and nobody's approved the spot for the unit.
Our honest recommendation
If you're renting for a single summer, or you're not sure you'll still be in the apartment next year, a portable unit is the sensible, low-commitment choice. If you're staying longer, own the property, or you've found the summer noise and running costs harder to live with than expected, a split system pays for itself in comfort and efficiency - just start the landlord or SVJ conversation before the heat does.
Weighing up your options for this summer, or planning ahead for next year? We install split systems and can talk through what's realistic for your building before you commit either way.