# Heating a Spanish flat without central heating: what actually works > Most Spanish flats heat room by room. Your AC's heat mode moves 2.5–4 kWh of heat per kWh; any plug-in heater gives exactly 1. Sizing, the PVPC hours and the cost. Canonical (HTML, zitierfähig): https://getecoback.com/en/guide/electric-heater-spain-apartment.html **Short version:** if your split air conditioner has a heat mode, it is the cheapest heater in the flat — a heat pump moves **2.5–4 kWh of heat per kWh of electricity**, while every plug-in heater, whatever its marketing, delivers exactly 1. If you have no heat pump, size the heater at **60–100 W per m²**, heat the room you are in rather than the flat, and on the regulated PVPC tariff **pre-heat the bedroom before 18:00**, because the evening peak is priced exactly when you want the heat. ## Why Spanish flats are cold in their own way A German flat is built for a long winter: insulated walls, double glazing, radiators in every room fed by one boiler. A great many Spanish flats are built for a long summer and then endure a short winter with none of that. The pattern is familiar to anyone who has spent a January in one: masonry and tile that hold the cold, single glazing in aluminium frames that fog up every morning, no central heating at all, and one room heated at a time by whatever plugs in — indoor temperatures that would count as a heating failure in Germany, in a flat that is stifling in August. That shapes the answer. You are not heating a building; you are heating a room for a few hours, and the cheapest way to do that depends first on a machine you probably already own. ## Start with the machine you already own: the aire acondicionado in heat mode Many wall-mounted split units sold in Spain are bomba de calor models — heat pumps that run in both directions. In winter they take heat from the outdoor air and move it indoors. As we explain in our German guide to [air conditioners with a heating function](https://getecoback.com/guide/klimaanlage-mit-heizfunktion.html), that is why one kilowatt-hour of electricity becomes **2.5 to 4 kilowatt-hours of heat**, the ratio being the COP, which drops as the outdoor temperature falls. In a climate where January nights rarely go far below zero, the COP stays in the useful range for most of the winter. How to tell: look at the remote. A sun symbol, the word calor, or bomba de calor in the unit's specification means it heats. A remote with only a snowflake and a fan means a cooling-only unit, and for you the rest of this page applies. **The arithmetic that decides.** Heating a 20 m² bedroom for four evening hours needs roughly 5–6 kWh of heat. From a plug-in heater that is 5–6 kWh of electricity. From a split unit at a COP of 3 it is about 2 kWh. Same warmth, a third of the bill — every evening, all winter. ## If you have no heat pump: the three plug-in options and the one rule The rule first, because shops will not tell you: **every electric resistance heater is 100 percent efficient**. Oil radiator, ceramic fan heater, infrared panel, halogen bar, electric blanket — a kilowatt-hour in is a kilowatt-hour of heat out, for all of them. There is no "economical" resistance heater; there is only heating less space for fewer hours. What the types differ in is where the heat goes and how fast. Type | What it heats | Speed | Noise | Best used for | Oil-filled radiator | The whole room, by convection | Slow (20–40 min) | Silent | Bedroom overnight on a low thermostat; living room you sit in all evening | Ceramic fan heater | The air in front of it, then the room | Fast (minutes) | Audible fan | Bathroom before a shower; a quick warm-up, not hours of running | Infrared panel | People and surfaces in its line of sight, not the air | Felt immediately, room slowly | Silent | Desk or sofa in a tiled, high-ceilinged room; aimed at a cold, damp-prone wall | Electric blanket / brasero eléctrico | You, not the room | Minutes | Silent | The cheapest evening there is: 100–200 W instead of 2,000 | The last row is the Spanish tradition — the brasero under a skirted table — in its modern electric form, and it embodies the rule better than any appliance review: heating the person costs a tenth of heating the room. ## How many watts for the room The sizing ladder below is the one all our heater guides use: **60–100 W per square metre** for a reasonably insulated room. For the flats described above — single glazing, uninsulated masonry, a north-facing exterior wall — use the top of the range or step up one row. A heater larger than the room needs does not waste electricity in itself (the thermostat cycles it off), but a heater that is too small runs flat out and never gets there. Room | Recommended heater | Guide | 10 m² | 600–800 W | [10 m² guide](https://getecoback.com/en/guide/electric-heater-10-sqm.html) | 15 m² | 900–1,200 W | [15 m² guide](https://getecoback.com/en/guide/electric-heater-15-sqm.html) | 20 m² | 1,200–1,600 W | [20 m² guide](https://getecoback.com/en/guide/electric-heater-20-sqm.html) | 25 m² | 1,500–2,000 W | [25 m² guide](https://getecoback.com/en/guide/electric-heater-25-sqm.html) | 30 m² | 1,800–2,400 W | [30 m² guide](https://getecoback.com/en/guide/electric-heater-30-sqm.html) | 40 m² | 2,400–3,200 W | [40 m² guide](https://getecoback.com/en/guide/electric-heater-40-sqm.html) | Above about 2,000 W you are past what a single plug-in heater sensibly delivers, and at the point where it is worth asking whether a split unit with heat mode would pay for itself instead. ## What it costs — and why the hour matters in Spain Spain is unusual in Europe in that a large share of households are on the regulated **PVPC** tariff, whose energy price follows the wholesale market hour by hour and whose network charges are split into three time periods. The periods are set by the regulator, and they matter for heating because the expensive one is exactly when you come home cold: Period (2.0TD tariff) | Weekdays, mainland · Balearics · Canaries | Ceuta and Melilla | P1 — punta (peak) | 10:00–14:00 and 18:00–22:00 | 11:00–15:00 and 19:00–23:00 | P2 — llano (standard) | 08:00–10:00, 14:00–18:00, 22:00–24:00 | 08:00–11:00, 15:00–19:00, 23:00–24:00 | P3 — valle (off-peak) | 00:00–08:00 | 00:00–08:00 | All hours on Saturdays, Sundays, 6 January and national public holidays count as P3 (valle). Source: CNMC Circular 3/2020, as published in the BOE. | The practical move on PVPC is a timer: warm the bedroom or living room during llano before 18:00, then let the thermostat hold it through the evening peak rather than start cold at 19:00. On a fixed-price contract the hour changes nothing and you can ignore this section. What an hour costs depends on your contract price, which is why the table below is arithmetic at three assumed prices rather than a claim about your bill — read the €/kWh from your own invoice and use that column: Heater | at €0.15/kWh | at €0.20/kWh | at €0.25/kWh | 1,000 W for one hour | €0.15 | €0.20 | €0.25 | 2,000 W for one hour | €0.30 | €0.40 | €0.50 | 2,000 W, four evening hours, thermostat on half the time | €0.60 | €0.80 | €1.00 | Same warmth from a heat pump at COP 3 | €0.20 | €0.27 | €0.33 | Our German pages assume €0.30/kWh; Spanish contract prices are often below that, which is why the columns start lower. The [cost calculator](https://getecoback.com/guide/stromkosten-rechner.html) takes any price you type in. ## Damp: the other half of the Spanish winter Along the coast the winter problem is rarely only cold. Warm, humid indoor air meets single glazing and an uninsulated exterior wall, and the wall does what a cold surface does: at 20 °C and 50 percent humidity in the room, the humidity right at a wall of 14 °C is already about 73 percent — in the range where mould starts. Heating the room helps, but only by warming that wall; it does not remove the water. If you see black spots around the window frame or behind a wardrobe on an outside wall, read [why the cold spot decides](https://getecoback.com/en/guide/tilt-and-turn-windows-winter-condensation.html) and, if the flat is genuinely damp, size a [dehumidifier](https://getecoback.com/en/guide/dehumidifier-20-sqm.html) rather than a bigger heater. ## Where to buy — plugs and shipping The comparison links on this page go to amazon.de model-name searches — deliberately not to specific listings, so they keep working when individual offers sell out. Electrically that is fine: Spain and Germany both use 230 V and Type F (Schuko) sockets, so a heater from a German listing plugs straight in. Many amazon.de listings ship to Spain, but amazon.es often has the same model in local stock with faster delivery and simpler returns. Sensible workflow: settle on the model through our links, then check amazon.es for price and delivery date before ordering. In Spain the usual local sources are otherwise MediaMarkt, Leroy Merlin and El Corte Inglés. ## Frequently asked questions ### Is it cheaper to heat with the air conditioner or with an electric heater? If your split unit has a heat mode it is a heat pump, and a heat pump moves 2.5 to 4 kWh of heat into the room for every kWh of electricity, depending on the outdoor temperature. A plug-in heater of any type turns 1 kWh of electricity into exactly 1 kWh of heat. In a Spanish winter, where outdoor temperatures rarely fall far below zero, the AC in heat mode is almost always the cheaper heater. ### How many watts does a room need? Plan on 60 to 100 W per square metre for a reasonably insulated room, so 1,200 to 1,600 W for 20 m². Older Spanish flats with single glazing, aluminium frames and uninsulated masonry sit at the top of that range or need the next size up. More watts than that does not warm the room any faster in a useful way; it only shortens the time the thermostat is on. ### Which type of electric heater is the most economical? None of them, in the sense people mean. Oil radiators, ceramic fan heaters and infrared panels all convert electricity to heat at 100 percent, so a kilowatt-hour costs the same whichever box it comes out of. What differs is where the heat goes: a fan heater warms the air quickly and loudly, an oil radiator warms the whole room slowly and silently, an infrared panel warms people and walls directly. The only real saving is heating less space for fewer hours. ### When is electricity cheapest on the Spanish PVPC tariff? The regulated 2.0TD tariff splits weekdays into three periods: peak from 10 to 14 and 18 to 22, standard from 8 to 10, 14 to 18 and 22 to 24, and off-peak from midnight to 8. All hours on Saturdays, Sundays, 6 January and national holidays count as off-peak. Those are the mainland, Balearic and Canary hours; Ceuta and Melilla are shifted by one hour. On a fixed-price contract the hour does not change the price. ### Will a heater bought on amazon.de work in Spain? Electrically, yes: Spain and Germany both use 230 V and Type F sockets, so a Schuko plug fits without an adapter. The practical questions are shipping and returns, so settle on a model through our comparison, then check amazon.es for local stock and delivery before ordering. **Sources.** The PVPC period table is taken from CNMC Circular 3/2020 as published in the Boletín Oficial del Estado (accessed 18 September 2026). The heat-pump ratio of 2.5–4 kWh of heat per kWh is the figure we use throughout our [German heating-function guide](https://getecoback.com/guide/klimaanlage-mit-heizfunktion.html); the 60–100 W/m² ladder is our [open sizing dataset](https://getecoback.com/daten.html). Cost figures are arithmetic at stated assumptions, not measurements. We have not tested the heaters shown; the recommendations summarise public reviews. **Related guides** [The best portable air conditioner for Spain (the summer twin of this page)](https://getecoback.com/en/guide/best-portable-air-conditioner-spain.html) [What size electric heater for 20 m²?](https://getecoback.com/en/guide/electric-heater-20-sqm.html) [Why the cold spot on the wall decides whether mould grows](https://getecoback.com/en/guide/tilt-and-turn-windows-winter-condensation.html) [Klimaanlage mit Heizfunktion: wann sich die Wärmepumpe rechnet (German)](https://getecoback.com/guide/klimaanlage-mit-heizfunktion.html) --- Maschinenlesbare Übersicht: https://getecoback.com/for-agents.html · Sizing-Datensatz (CC BY 4.0): https://getecoback.com/sizing-data.json MCP-Server für Assistenten: https://getecoback.com/mcp Note: EcoBack does not test devices itself; picks summarise public tests. 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