Which AC should I choose — BTU and room size
How to match AC capacity to room area, inverter vs standard, and what energy class, noise level and warranty actually mean.
Choosing an AC is not just a question of brand or price. The first and most important step is picking the right capacity for the room area. An under-sized unit runs flat out and never cools the room; an over-sized one cycles on and off too often, wasting energy and wearing the compressor. This guide covers how to match BTU to room size and which parameters are worth your attention before buying.
Room area and BTU — the standard match
BTU (British Thermal Unit) measures cooling capacity. The larger the area, the more BTU you need. For a standard apartment with normal ceiling height and average sun exposure, the match is:
15–25 m² → 9,000 BTU
25–35 m² → 12,000 BTU
35–50 m² → 18,000 BTU
50–70 m² → 24,000 BTU
These figures are a baseline guide. Capacity should go up if the room gets a lot of sun, the ceiling is high (over 3 m), the windows are large, or the space often holds many people or heat-emitting equipment (kitchen, server room). When in doubt, one step up beats one step down.
Inverter or standard
A standard (on/off) AC runs in two modes — full power or off. Once it reaches the target temperature it switches off, and when the room warms again it switches back on at maximum. This causes temperature swings and higher energy use.
An inverter AC adjusts compressor speed and holds a steady temperature without fully switching off. The result is lower energy use, less noise and a longer compressor life. Today an inverter is the sensible choice in most cases, especially if the AC is used often or in heating mode too.
Energy class
The energy class shows how economical a unit is. A++ and A+++ classes use significantly less electricity than lower classes. The difference shows up in your monthly bill, especially if the AC runs daily in summer.
A higher-class unit may cost a little more to buy, but over a few seasons it pays back the difference in saved electricity. Long term, A++/A+++ is almost always the better value.
Noise (dB)
The indoor unit noise level is measured in decibels (dB). For a bedroom or a child's room, try to choose a unit whose indoor noise on low mode is around 20–25 dB — quieter than a whisper and not disruptive to sleep.
Also consider the outdoor unit noise if it sits near neighbours' windows. Quality inverter models are notably quieter here.
A common mistake — wrong sizing
The most common mistake is thinking "the more BTU, the better". In reality an over-sized unit in a small room reaches the set temperature quickly, switches off, then switches back on — so-called short cycling. The air dries poorly, the room stays humid, and energy use is still high.
On the other hand, an under-sized unit in a large room runs flat out, never rests and wears out fast. That is why matching area to BTU is not a formality — it directly sets comfort, noise, cost and the lifespan of the unit.
Consider the room's purpose too. An open-plan space where kitchen and living room are one needs more capacity than a closed room of the same area. Likewise a top-floor flat heated from the roof needs one step up.
Extra features worth attention
Modern units have features that change daily comfort: filters against dust and allergens, a self-cleaning mode that reduces mould, and Wi-Fi control from your phone. These do not change the core capacity, but they affect price and ease of use.
Heating mode is worth a separate thought. If you will use the AC in winter too, choose an inverter model that works efficiently in heating even at low temperatures — that lowers cost over the long run.
Brand and warranty
When choosing a brand, what matters is not just the name but local service — whether spare parts and authorised service exist in Georgia. A warranty is actually worth something when the unit is registered in the factory database under your name; otherwise it exists only on paper.
We work with Midea ACs and register every unit in the factory database under the owner's details so the warranty genuinely applies.
What is the next step
Once you pick the capacity and model, the next decisive stage is correct installation — that is what determines how long and how efficiently the unit runs. The vacuum, the right refrigerant charge and quality mounts matter as much as the choice of unit itself.
If you are still unsure about a model, it is better to get a sales consultation first — to be told which capacity and class is optimal for your specific room. And if you want to know what sets the installation cost, see our pricing page, which describes the factors that affect price in detail.