Cooling

Air conditioning

This page is for anyone dealing with summer heat in an apartment or house and considering air conditioning, whether just for one room or as a heating supplement. We explain the differences between unit types, what needs to be sorted before installation, and what affects operation.

Split versus multisplit: which is suitable for your flat or house?

Split The system has one outdoor and one indoor unit and is suitable for cooling or heating a single room. Multisplit It drives multiple indoor units with a single outdoor unit at once, which is useful where you want to air-condition several rooms but do not wish to have more than one outdoor unit on the façade. For larger apartment buildings or commercial premises, a central VRF system is used, where one outdoor source serves dozens of indoor units.

Wall-mounted, cassette and ceiling cassettes units

The most common is wall-mounted ceiling-mounted wall unit, cheapest to install, but most visible. Cassette The unit is installed in the suspended ceiling and discharges air in all directions; it is suitable for rooms with a suspended ceiling where the air needs to evenly cover the entire space. cassette The unit hangs from the ceiling without requiring a suspended ceiling and represents a compromise between performance and aesthetics.

Typ jednotky	Where it fits	Installation requirements
Wall-mounted	one room, flat	simplest, without a suspended ceiling
Cassette	living room, office with suspended ceiling	requires a suspended ceiling
cassette	room without a suspended ceiling, larger area	moderately demanding
Multisplit / VRF	more rooms, a whole flat or house	planning of refrigerant distribution lines

Air conditioning as a heat source

Air conditioning with heating capability is technically an air-to-air heat pump. As a primary heating source, it is better suited to well-insulated flats and smaller houses with open layouts where warm air circulates easily throughout the space. Where it is necessary to heat several separate rooms evenly and also provide hot water, a water-based system makes more sense, see the page on... For details. heat pumps.

What affects the price

The price depends on the number and type of indoor units, capacity, length and complexity of refrigerant piping between the outdoor and indoor unit, building modifications (wall penetrations, electrical installation) and whether it is a simple split, multisplit or VRF system. An indicative range can be found at page with price guidesThe exact price will only be determined after an on-site inspection.

SVJ consent and placement of the outdoor unit

In apartment buildings, the façade is a common area, so installing an outdoor unit usually requires consent from the building's owners' association or the manager. It is also worth considering aesthetics (visibility from the street), orientation (the south side means higher summer load but more sun on the façade), and distance from neighbours' windows due to noise and discharged warm air.

Subsidies

Air conditioning for cooling only is not an eligible item for subsidies. However, an air-to-air heat pump used also for heating may qualify under the programme. Nová zelená úsporám, whose terms change over time and need to be verified currently. In Prague, the capital city's programme is also running. Clean Energy Prague, which also targets air-to-air heat pumps, outside Prague you will usually not find a similar local programme.

Operation and maintenance

Filters in the indoor unit are cleaned regularly, depending on the dustiness of the environment, roughly at intervals of weeks to months. The outdoor unit requires free space for airflow and occasional checks of condensate drainage. Annual servicing helps maintain performance and compressor lifespan.

Common mistakes

The most common mistakes include an undersized unit capacity relative to the room's area and orientation, positioning the indoor unit so it blows directly onto a workspace or bed, underestimating the noise of the outdoor unit for neighbours, and starting installation without prior consent from the building's owners' association, which can lead to disputes or the need to relocate the system.

Frequently Asked Questions

Can my air conditioner also provide heating in winter?

Yes, most modern split air conditioners are also air-to-air heat pumps and can both heat and cool. However, heating output and efficiency decrease as the outdoor temperature drops, so in severe frost they are often less effective than a dedicated air-to-water heat pump connected to a water-based heating system. Nevertheless, as a supplementary or primary heat source in a well-insulated room or flat, they work perfectly well.

Do I need the building's owners' association consent to install an air conditioner?

In most apartment blocks, yes, because the outdoor unit and its fixing to the façade affect the common parts of the building. Therefore, even as a flat owner, you usually request consent from the building's owners' association or the building manager before ordering the installation, not after it.

How many units do I need for my flat?

It depends on the layout and whether you want to cool each room individually. One outdoor unit can drive multiple indoor units simultaneously via a so-called multisplit system; for larger flats or houses, a central system (VRF) with a single outdoor source for the entire building is also an option.

How noisy is an air conditioner?

The outdoor unit has a declared noise level in the manufacturer's technical data sheet. If it is to be installed near bedroom windows or a neighbour's property, placement, distance and possibly quieter night-time operation must be addressed during the installation design, as remedying this afterwards is more difficult.

How often should an air conditioner be serviced?

The filters of the indoor unit should be cleaned by the user following the instructions, typically at intervals ranging from weeks to months depending on usage. Once a year, professional servicing is recommended, checking the refrigerant level, cleaning the heat exchanger and condensate drainage. For systems with a larger amount of refrigerant, the law additionally requires regular inspection of circuit tightness.