A 22 m² studio with a heat pump and a shocking winter bill: why two convector panels are the answer
Jaga
In the first week of February 2026, with Estonia in a deep cold spell, a landlord in Tallinn wrote to us through the store's contact form. Her small rental studio is heated by an air-source heat pump, and the tenant's electricity bill for the cold weeks had been, in her words, ridiculous. Her question was the one we get most often in winter: is an infrared radiator more energy-efficient than a heat pump?
The customer's problem
The apartment is 22.5 m² in total, with a main living area of about 15 m². In mild weather the heat pump is the most efficient heater in the building. At -20 °C its coefficient of performance drops and it runs almost continuously, and in a small space it also tends to deliver more heat than the room needs because its control is coarse. The result is a high bill and an apartment that is alternately too warm and too cold.
What we did
We answered honestly: a correctly installed heat pump has a higher efficiency than any electric radiator, but it consumes continuously, while an electric panel with a thermostat consumes exactly as much as needed to hold the set temperature in that room and nothing in rooms you do not heat. For a 12 m² room our rule of thumb is about €1.5 a day for a GPO panel at typical winter use (an estimate: the real figure depends on the electricity price, insulation and the hours the panel runs).
She sent photos of the apartment. Based on them we recommended two white metal convector panels: 770 W under the bedroom window and 550 W under the kitchen window. The bedroom panel carries the room; the heat pump helps distribute its heat by mixing the air; the kitchen panel is an auxiliary that runs only when needed. Both match the interior colours, mount on the wall, have built-in thermostats and are controlled from the phone.
Benefit for the customer
What this setup is meant to give her: heating exactly the space that is used, at a set temperature, with a controllable daily cost, and a heat pump that returns to being a mild-weather appliance instead of a January liability. For a landlord there is a second benefit: app control and a 5-year warranty on the panels mean fewer calls from the tenant.
Technology used
Infrared Convection Heater 770 W and 550 W: painted steel panels with a built-in Wi-Fi thermostat, controlled from the GPO Home app, 5-year warranty. Both work with the GPO Smart Plug's price logic and with the BLE room sensor if the thermostat should measure temperature away from the panel.
Improvements and know-how: glass vs ceramic vs metal
Her second question, whether ceramic, glass and metal panels differ beyond looks, deserved a full answer, and it is the part of this article people will search for. Glass and ceramic panels work the same way but differ in detail: 4 mm tempered glass heats up faster than 8 mm ceramic and also cools faster; glass blends into an interior (a mirror-like surface, sometimes indistinguishable from the wall) while ceramic looks like a heater; glass is easier to wipe clean; ceramic is pleasant to touch, like a warm tile, and shows no fingerprints; glass panels are lighter; in our glass panels the heating element's conductive tracks are much denser, which heats the surface more evenly without local hot spots, important for reducing stress in the glass; ceramic panels have a metal back wall, so when switched on at sub-zero temperatures you may hear a faint click from the metal expanding, which glass does not do; ceramic comes in more sizes and is cheaper; glass has the premium look and the premium price. Metal convectors are the budget, no-nonsense option for under-window placement. (We also test glass panel strength on camera: watch the video.)
What's next
Small rental apartments with a heat pump as the only heater are common in Tallinn and Tartu, and the same two-panel recipe applies to most of them. We plan a short "heat pump + panel" sizing guide in Estonian with a per-room wattage table. For landlords with several units, the Smart Plug's price threshold can cap the panels' consumption during the most expensive hours without touching the tenant's comfort settings.
FAQ
Is an infrared panel more efficient than a heat pump? No, a heat pump moves more heat per kWh. But a panel with a thermostat consumes only what the room needs, and in a small space at very low outdoor temperatures the panel often costs less per month in practice.
What wattage for a 15 m² room? As an auxiliary to a heat pump in a room like this, 550–770 W under the window is typical.
Glass or ceramic? Glass for looks and fast response, ceramic for a warm-to-touch surface and lower price, metal for budget under-window convectors.
Where to get it
You can also see the panels in person at our office in Tallinn, Peterburi tee 38/9.