Multi-split air conditioning in Batumi and ducted systems

When you need a multi-split, and when separate units will do

A separate air conditioner in each room is cheaper and easier to repair. A multi-split is chosen for other reasons: the facade has only one outdoor unit position for the apartment, the building doesn't allow units on the balcony, or the owner doesn't like the look of a row of three units on the wall. Separate splits are covered on the page about wall-mounted air conditioner installation.

How a multi-split system works

Each indoor unit has its own pair of copper pipes and its own cable from the outdoor unit, and the runs don't merge along the way. At the cage on the facade a bundle of four to six pipes comes together, and it needs a larger hole than usual, or two side by side. We usually run the pipes under the hallway ceiling in plasterboard boxing and branch off to the rooms from there.

The outdoor unit is sized for the rooms that run at the same time. The combined capacity of the indoor units can be greater than that of the outdoor unit, because the living room by day and the bedrooms at night rarely need full power together. We build the system only from combinations allowed by the manufacturer's combination table, and check the limits on pipe run length and height difference before buying.

All the indoor units work in the same mode: while one room is being heated, another can't be cooled. This shows in spring and autumn if the living room is on the sunny side and the bedrooms are in the shade.

Ducted air conditioners: what is most often overlooked

A ducted unit sits above the ceiling of the hallway, bathroom or walk-in wardrobe, and the air goes to the rooms through ducts. How much height a ceiling like that takes is shown on the page about Euro renovation, and how to close it in and where to leave hatches is covered in the comparison of stretch ceilings and plasterboard. What comes to light once the installation is done:

• return air: the air delivered to a bedroom has to get back to the unit through a grille in the door, a gap under the door leaf or a separate duct, otherwise the room is stuffy with the door shut and the unit hums;
• duct insulation: cold air in the boxing causes condensation on the duct walls, so we use insulated ducts and tape the joints;
• a single temperature: an ordinary ducted unit holds it by one sensor, and the sunny room stays warmer than the rest until zone dampers are fitted;
• noise: in a narrow duct and a small grille the air whistles, so we size the ducts by airflow and choose grilles with spare area.

Fresh air from outside is brought to the ducted unit through a separate duct, and we decide on this together with the apartment ventilation while the ceiling is still open.

Cassette and floor/ceiling units

With a cassette unit, all you see in the room is a square panel in the ceiling, and the air spreads out of it in four directions. A unit like this suits a large kitchen-living room, where an 18,000–24,000 BTU wall-mounted unit would blow at one spot, but it needs spare height above the ceiling and a hatch around the casing. A floor/ceiling unit is hung under the ceiling or placed low on a wall where the ceiling can't be lowered. With many brands, both types can be connected either to their own outdoor unit or to a multi-split system.

How the order of work differs from ordinary splits

The general order is the same as for other climate equipment during a renovation: pipe runs before plastering, units after painting. But a multi-split has more decisions that can't be put off:

1. we choose the combination of indoor units from the manufacturer's table before the rough work, together with the furniture layout and the ceiling type;
2. before ordering, we check the outdoor unit's dimensions and weight against the cage;
3. we label each pair of pipes at both ends, at the cage and at the indoor unit;
4. we pressure-test each pipe run separately, so that if the pressure drops we know straight away which one is leaking;
5. after hanging, we vacuum each pipe run and start the units one at a time first, then all together.

Without labelling, the remote in the bedroom can end up switching on the air conditioner in the living room. With a ducted unit, we measure the temperature at each grille with the doors closed.

How much multi-split air conditioning costs in Batumi

A multi-split for two or three rooms with equipment and installation costs from 8,100 to 10,800 ₾. This is a guide figure before the calculation. It comes out dearer than separate air conditioners in each room: the extra pays for a single position on the facade and walls without additional units.

If you have already bought the equipment, installing the outdoor unit costs 360–420 ₾, and each indoor unit 180–215 ₾. This is labour only: the pipe runs and materials are priced in the estimate, and a metre of pipe run beyond the standard length costs 72–84 ₾ including materials.

A ducted 18,000–24,000 BTU air conditioner with ductwork and installation comes to 8,400–10,800 ₾, and the plasterboard ceiling under it is priced separately. The final cost is set after the site measurement and once the estimate is agreed, with every unit and every pipe run as a separate line.