Energy
Inverter or not?
Almost all splits are inverters these days: they vary the compressor speed instead of switching on and off. They use less, make less noise and the temperature doesn’t yo-yo. If you’re offered one that isn’t, ask why.
08 Guide
What’s worth knowing before you buy air con
Short answers to the questions people ask most, with real numbers and no brochure-speak. If anything’s still unclear, drop us a line.
- 1article with a converter
- 9short answers
- 12catalogue terms
Article Capacity · 6 min
Frigorías, kW and BTU: how to read what’s on the box
Three units for the same thing. What each one is, how to convert between them and how much each room needs, with a converter.
Read the articleQuick questions by topic
Capacity
What happens if it’s too small or too big?
Too small and it runs flat out all summer and can’t keep up in the afternoon. Too big and it keeps starting and stopping, cools in fits and starts and costs you more. That’s why we round to the first size that covers the room, not the one above.
Work out my capacityNoise
How noisy is a split?
20 dB304050
A wall split usually goes from about 20 dB on its lowest speed to about 40 on its highest. For sleeping, get one with a night mode and don’t put it over the bed.
Energy
What temperature should I set?
It’s comfortable without the unit overworking. Every degree you go down in summer, or up in winter, shows on the bill.
Care
How often should I clean the filters?
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Once a month while you’re using it. They come out when you lift the cover, get washed in lukewarm water and dried in the shade. The insides are best left for the service.
Energy
Cooling or heating: which uses more?
4kWh of heat
for every kWh of electricity
Here, summer uses more: it lasts longer and the difference with outside is bigger. In winter, a heat pump gives out about four times the electricity it uses as heat.
Noise
Where should the outdoor unit go?
In the shade if possible, with clear space in front so it can breathe, and on rubber mounts so vibration doesn’t pass to the wall or the neighbours. If the façade belongs to the community, you sometimes need permission.
Care
What refrigerant does a new split use?
Almost all new units use R-32, which warms the planet about three times less than the R-410A in units from a few years back. Only a technician with an F-gas certificate can charge or recover it.
Care
How long does a split last?
10–15years, if properly fitted and serviced
What shortens it most: fitting without a vacuum, low refrigerant and dirty filters. After ten years, before a pricey repair, it’s worth checking what a new one would use.
08.1 Glossary
Catalogue terms, in one line
- Frigoría
- The cooling a unit delivers in an hour. 1 frig/h = 1.163 W. It’s the Spanish unit you’ll see on boxes here.
- kW
- The same power in the unit used on the EU energy label.
- BTU/h
- The imperial unit: 12,000 BTU/h is 3.5 kW.
- SEER
- How much cooling it gives per kWh of electricity, averaged over the summer.
- SCOP
- The same for heating, averaged over the winter.
- Inverter
- A compressor that changes speed instead of switching on and off.
- Heat pump
- A unit that gives both cooling and heating: in winter it reverses the cycle.
- 1×1 split
- One unit inside and one outside.
- Multi-split
- Several indoor units with a single outdoor one.
- Ducted
- A unit in the suspended ceiling that sends air out through grilles.
- Cassette
- A ceiling unit that blows out on all four sides.
- R-32
- The refrigerant in almost all new units.
Already got air con and it’s acting up?
If it drips, smells or isn’t cooling, three questions will tell you what it might be and what to check before you call.