Choosing an air conditioner is like choosing your desk mate: if you get it wrong, you’ll spend the summer suffering in silence. Here you’ll find why to get one, how to choose it well, and where not to get ripped off. Irony included, sweat excluded.
Why install it (besides the fact that you love breathing)
Real comfort: stable temperature and controlled humidity. Goodbye “sauna/igloo” effect.
Productivity: people work better in the office if they’re not melting on the keyboard.
Healthier air (within the limits of an AC, not a hospital): filters that capture dust and pollen; no miracle promises.
Heat pump function: many models heat well in mid-seasons. Goodbye October radiators.
Smart control: app, scheduling, geolocation. Yes, you can turn it off for those who leave it at 18°C “because it cools faster”.
Types: who does what
For home
Wall split: the classic. Quiet, efficient, quick installation.
Multi-split: one outdoor unit, several indoor units. Fewer “condos” on the balcony.
Ducted: invisible vents and uniform comfort. Requires a false ceiling (and a good installer).
For office
Ceiling cassettes: happy open spaces, 360° diffusion.
Ducted with AHU/HRV: air conditioning + fresh air (which air conditioners alone do not provide).
VRF/VRV: for medium-large offices, many rooms, centralized control and, if you want, simultaneous heating/cooling.
Server/Technical rooms: dedicated 24/7 units, N+1 redundancy if your data is worth more than coffee.
Avoid (if you can): portables with a hose out the window. They cool little, are noisy, and steal your likes.
Right size: goodbye “let’s just get the big one”
The golden rule: don’t oversize. Modern ACs modulate, but if you overdo it, you’ll get high consumption and annoying on/off cycles.
Quick estimate (well-insulated residential)
Up to 15 m² → ~2.0–2.5 kW (7,000–9,000 BTU/h)
15–25 m² → ~2.5–3.5 kW (9,000–12,000 BTU/h)
25–40 m² → ~3.5–5.0 kW (12,000–18,000 BTU/h)
40–60 m² → ~5.0–7.0 kW (18,000–24,000 BTU/h)
Very sunny rooms, glass walls, high floors or lots of people/PCs? Increase the estimate. Basements and shaded north sides? Reduce. In the office, count people + machines + lights: an open space with 20 people “heats up” more than a pizzeria.
Efficiency without headaches
SEER/SCOP: the higher they are, the less you pay on your bill (seasonal cooling/heating).
Energy class: A++/A+++ is your friend.
Inverter: now standard. Modulates power, cuts consumption and noise.
Refrigerant: today R32 dominates; R290 is also seen in some solutions. What matters is that the system is properly installed (vacuum, leak test, correct charge).
Humidity: half of comfort
Home target: 45–60% RH.
Office target: 40–55% RH.
Dry mode in mid-seasons = less “sticky” with few kWh.
Noise: you want cool, not a helicopter
Indoor units: < 25 dB(A) in “quiet” = great for bedrooms/meetings.
Outdoor units: check nominal dB(A) and location (no echoing courtyards). Anti-vibration feet and solid supports.
Placement: where yes, where no
Inside
High wall, free air in front, not blowing on the sofa or the sensitive colleague’s desk.
Respect distances from the ceiling: that extra centimeter makes a difference (for airflow).
Outside
Free air in front and behind, no “oven” compartments.
If exposed to the sun, a light screen helps.
Condensate drain with constant slope; if needed, a quiet pump.
Controls & Smart
Wi-Fi/app: scheduling, scenarios, temperature limits (bye 18°C).
CO₂ sensors (offices): if “stale” air rises, add HRV/AHU: remember, AC does not bring in fresh air.
BMS (offices): centralized control, schedules, consumption reports. Bye weekend waste.
Maintenance (yes, it must be done)
Filters: vacuum/wash every 2–4 weeks in summer.
Coils and fans: professional annual cleaning.
Condensate drains: free from algae/sludge.
Leak checks: if required for charge/fluid, better to comply than get fined.
What to look for in the technical sheet (without being hypnotized by the LEDs)
Power at 35°C outside (cooling) and at -7/2°C (heating if needed).
Actual SEER/SCOP, not “up to”.
Noise (dB(A)) at each speed.
Airflow (m³/h) and throw: needed to get cool air where you live/work.
Functions: Dry, i-see/eye (presence sensors), 3D flap, anti-freeze, silent mode.
HRV/BMS compatibility (offices) and centralized control.
Warranty & support: who will help you after installation?
Epic mistakes to avoid
Oversizing “so I’m safe”. No, you’ll just use more energy.
No HRV in the office: recycled air ≠ fresh air.
Outdoor in an oven: outdoor unit closed in a niche… poor thing.
Blowing on people: your colleague will love you (not in a good way).
Forgetting condensate: puddle today, stain tomorrow, curse the day after.
Cheap installation: no vacuum, no leak test = guaranteed problems.
How much does it cost to use? (mini-compass)
Estimated annual consumption ≈ (hours of use × average absorbed power).
Absorbed power ≈ cooling power / EER (or SEER).
Quick example: 3.5 kW cooling, SEER 6 → average absorption ~0.6 kW. If you use it 300 hours in summer ⇒ ~180 kWh. Multiply by the cost per kWh and you have the ballpark figure. With photovoltaic, shift peaks to production hours and smile.
Home vs Office: differences that matter
Internal loads: in the office people+PCs+printers generate heat. Dedicated calculation, not “by eye”.
Zoning: meeting rooms, open spaces, closed offices: need separate controls.
Noise: ultra-quiet meeting rooms, more tolerant common areas.
Service continuity: for critical offices consider redundancy and remote alarms.
Regulations and fresh air: remember the AC + ventilation combo.
Smart path in 7 steps (this is how we do it)
Site inspection: measurements, exposures, internal loads, expected noise.
Load calculation: yes, with real numbers.
System choice: split/multi/VRF/ducted + possible HRV.
Design: locations, drains, passages, electrical, controls.
Proper installation: vacuum, leak test, weighed charge, commissioning.
Calibration: curves, flows, temperature limits, programming.
Maintenance: annual plan and seasonal checks.
Straightforward FAQ
Does it cool even with 40°C outside?
Yes, if properly sized and the outdoor unit can breathe. If it’s in an oven… it cries.
Can I use only Dry mode?
When humidity is high and temperature isn’t crazy: yes, often that’s enough.
Does it also heat?
Many models do (heat pump). Perfect in mid-seasons.
Do I need a 3 kW or 6 kW meter?
Depends on how many units and simultaneous absorption. We’ll calculate it for you, no surprise blackouts.
Conclusion (with shameless invitation)
Do you want an air conditioner that really cools, doesn’t annoy you, and doesn’t empty your wallet?
With Gruppo Impianti Ristrutturazioni you get: site inspection, serious calculation, clean installation, and real support.
Bring us floor plans, photos of the rooms and, if it’s an office, how many people and PCs. We’ll prepare a tailor-made proposal for you — irony included, sweat excluded.
