03 Room-by-room calculator
Which air con does your home need?
Add each room with its size and which way the windows face. We’ll tell you how much cooling each one needs, which system suits you and how much electricity it’ll use. Add each room with its size and which way the windows face. We’ll tell you how many kW of heat each one needs, which system suits you and how much you save compared with an electric radiator.
- 1Roomssize, sun, floor
- 2Unitsystem and price
- 3Quoteby email, with the workings
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The calculator needs JavaScript. In the meantime, the quick sum: 90 frigorías per m², plus 15% if it gets a lot of sun or is a top-floor flat. A 24 m² living room comes to about 2,500 frig/h, roughly 2.9 kW.
For more than 8 rooms, it’s best we see it in person.
03.2 What it’ll cost to run
A new inverter uses half the electricity of a fifteen-year-old unit With a heat pump, the same heat costs a quarter as much
We compare a new unit with a SEER of 6.1 against an old one with a SEER of 3. Change the hours and your electricity price: the result updates straight away. We compare a heat pump with a SCOP of 4 against electric radiators, which give one kWh of heat for every kWh of electricity. Change the hours and your electricity price.
On your bill it’s the energy charge, ‘término de energía’. If you’re not sure, leave 0.15.
A simple sum: power the home needs × hours × 30 days × months ÷ unit efficiency. It’s for comparing, not for guessing your bill.
03.3 How we work it out
No hidden sums
We start from the floor area and multiply by what matters most round here: sun, windows and roof. Then we round up to the next catalogue size.
| What | Option | Cool | Heat |
|---|---|---|---|
| Base | per m² | 90 frig/h | 0.075 kW |
| Windows facing | north | ×0.90 | ×1.10 |
| east | ×1.00 | ×1.00 | |
| south | ×1.15 | ×0.90 | |
| west | ×1.15 | ×1.00 | |
| Glazing | double | ×0.90 | ×0.90 |
| standard | ×1.00 | ×1.00 | |
| single | ×1.15 | ×1.15 | |
| Floor | top floor or attic | ×1.12 | ×1.12 |
| Use | shop or office | ×1.20 | ×1.00 |
| People | each one above two | +100 frig/h | — |
Catalogue sizes
The result goes up to the first size that covers it. For heating, a heat pump gives 10% more than it does for cooling.
- 1,500
- 2,000
- 2,500
- 3,000
- 3,500
- 4,500
- 5,500
- 6,500
- 8,000
- 10,000
frig/h · 1 frigoría/h = 1.163 W
03.4 What a calculator can’t see
- Note 1
Where the pipe runs. The more metres to the outdoor unit, the more material and hours.
- Note 2
The façade. If it belongs to the community, you sometimes need permission to hang the unit.
- Note 3
The fuse box. A large unit may need a new circuit from the fuse box.
- Note 4
The suspended ceiling. Without one, ducted systems mean building work; with one, they’re often the best option.
All of this shows up at the visit, which is free. Frigorías, kW and BTU, explained slowly