Home Heat Pump Guide

Fan Convector Radiators for Heat Pumps

Fan convector radiators solve one of the biggest practical challenges of heat pump installations: delivering enough heat from a compact unit when the flow temperature is much lower than a traditional boiler system. They are not always necessary, but when wall space is limited or a room has high heat demand, they can be the difference between a heat pump system that works beautifully and one that struggles.

This guide explains how fan convectors work, when they make sense, what they cost, and how to choose the right one for your heat pump system.

How Fan Convector Radiators Work

A standard radiator relies on two mechanisms to emit heat: radiation (heat travelling directly from the hot surface to objects in the room) and natural convection (warm air rising from the radiator surface and circulating around the room). At the low flow temperatures a heat pump uses (35–50°C), both of these mechanisms are significantly reduced compared to a boiler running at 70–80°C.

A fan convector adds a third element: forced convection. A small, quiet fan draws room air across a heat exchanger (a finned coil or panel), dramatically increasing the rate of heat transfer. The fan forces more air across the hot surface per minute than natural convection alone, extracting significantly more heat from the water flowing through the unit.

The result is that a fan convector can deliver 2 to 3 times more heat than a standard radiator of the same physical dimensions at the same flow temperature. At 45°C flow temperature, a fan convector measuring 600mm × 800mm can easily match the output of a Type 22 panel radiator measuring 600mm × 1,600mm.

Why Fan Convectors Excel at Low Flow Temperatures

The key advantage of fan convectors becomes more pronounced as flow temperatures drop. Here is a comparison:

Standard Type 22 Radiator (600 × 1000mm)

  • At 75°C flow (ΔT50): approximately 1,800W
  • At 55°C flow (ΔT35): approximately 1,170W (65%)
  • At 45°C flow (ΔT25): approximately 790W (44%)
  • At 35°C flow (ΔT15): approximately 430W (24%)

Fan Convector of Similar Dimensions

  • At 75°C flow: approximately 3,000–4,000W
  • At 55°C flow: approximately 2,200–3,000W
  • At 45°C flow: approximately 1,800–2,500W
  • At 35°C flow: approximately 1,200–1,800W

At 45°C flow, the fan convector delivers roughly 2.5–3 times more heat than the standard radiator. At 35°C, the advantage grows even further — the fan convector still produces meaningful heat while the standard radiator is barely warming the room.

This is why fan convectors are particularly valuable for heat pump systems designed to run at the lowest possible flow temperatures (35–45°C), where heat pump efficiency is at its best.

Types of Fan Convectors

Wall-Mounted Fan Convectors

These look similar to a standard radiator and mount on the wall at a similar height. They are the most common type for domestic heat pump installations. The fan is housed behind a grille, and air is drawn in from the bottom and expelled from the top (or front, depending on the design).

Wall-mounted units are straightforward to install, especially when replacing an existing radiator — the pipework connections are in a similar position.

Floor-Standing Fan Convectors

These sit on the floor, often beneath windows. They are popular in commercial settings but increasingly available for domestic use. Floor-standing units can deliver very high outputs and are useful in rooms with limited wall space or where radiators would block large windows.

Low-Level / Skirting Fan Convectors

Ultra-slim units that sit at skirting board level, running along the base of the wall. They are very discreet but have lower output per unit length compared to wall-mounted models. They work best in rooms with long, uninterrupted wall runs.

Trench or In-Floor Fan Convectors

Installed in a trench cut into the floor, with a grille flush with the floor surface. Common in commercial and high-end residential projects, particularly in front of floor-to-ceiling windows. Installation is more complex and expensive, but the result is virtually invisible heating.

When Fan Convectors Make Sense

Fan convectors are not always necessary. In many UK homes, appropriately sized standard double-panel convector radiators provide perfectly adequate output for heat pump operation. Fan convectors earn their place in specific situations:

Limited Wall Space

If a room needs a radiator 1.5–2 times larger than the current one and there simply is not enough wall space, a fan convector delivers the required output in a smaller footprint. This is the most common reason for choosing a fan convector in a domestic setting.

High Heat Loss Rooms

Large open-plan living areas, rooms with extensive glazing, or poorly insulated rooms with limited upgrade options may need more heat than even the largest standard radiator can deliver at 45°C. A fan convector can bridge the gap without raising the flow temperature.

Maximising Heat Pump Efficiency

If you want to run your heat pump at the lowest possible flow temperature (35–40°C) for maximum COP, fan convectors allow this without needing enormous radiators. This is the efficiency-optimisation argument — the energy savings from running at a lower flow temperature can be significant over the system's lifetime.

Rapid Warm-Up

Fan convectors heat rooms faster than standard radiators because they move air actively. If your lifestyle involves being away during the day and wanting the house warm quickly in the evening, fan convectors in key living areas can make a noticeable difference — though this should be balanced against the benefits of running the heat pump continuously at lower output.

Cooling Mode

Some fan convectors can operate in reverse — blowing room air over a chilled water coil to provide cooling in summer. This requires a heat pump capable of providing chilled water and appropriate controls, but it is a growing trend in the UK as summers become warmer. Standard radiators cannot provide cooling.

Noise Levels

Noise is the main concern people raise about fan convectors, and it is a fair question. The fan produces audible noise, unlike a standard radiator which is essentially silent.

Actual Noise Levels

  • Low speed: 22–28 dB(A) — barely audible, quieter than a whisper
  • Medium speed: 28–35 dB(A) — similar to a quiet room with a fridge running
  • High speed: 35–42 dB(A) — comparable to a quiet library or gentle rainfall

For context, a typical modern fridge runs at 35–40 dB. Most fan convectors spend the vast majority of their time on low or medium speed, where they are barely noticeable. High speed is only needed during rapid warm-up or on the very coldest days.

Managing Noise

  • Choose a quality unit: Premium models from established manufacturers (Jaga, Biddle, Myson, Sabiana) are engineered to minimise noise. Budget units may use cheaper fan motors with more vibration.
  • Position thoughtfully: Avoid placing fan convectors directly adjacent to seating areas or beds where low-level noise is most noticeable.
  • Use variable speed controls: Most fan convectors have variable speed settings. Running on low speed 90% of the time keeps noise minimal.
  • Consider room function: Fan convectors are ideal for living rooms, kitchens, and hallways. For bedrooms, standard radiators (which are silent) may be preferable unless noise sensitivity is low.

Cost of Fan Convector Radiators

Unit Costs

Fan convector prices vary by size, output, and manufacturer:

  • Small wall-mounted unit (1–2 kW output): £300–£500
  • Medium wall-mounted unit (2–3 kW output): £400–£650
  • Large wall-mounted unit (3–5 kW output): £500–£800
  • Floor-standing or trench models: £600–£1,200+

Installation Costs

Installation costs are similar to standard radiators, with an additional requirement for an electrical connection (the fan needs a power supply). Typical installation costs:

  • Replacing an existing radiator with a fan convector: £150–£300 labour
  • New installation (new pipework and electrics): £250–£450 labour

Total Cost per Unit

Expect to pay £450–£1,000 per fan convector fully installed, compared to £200–£500 for a standard Type 22 radiator. The premium is significant, but in rooms where they are genuinely needed, the benefit in terms of comfort and heat pump efficiency more than justifies the cost.

Running Costs

The fan itself uses very little electricity — typically 5–30 watts depending on speed. Over a full heating season, the fan might add £5–£15 to your electricity bill per unit. This is negligible compared to the energy savings from running the heat pump at a lower, more efficient flow temperature.

Popular Fan Convector Brands in the UK

Jaga

Belgian manufacturer with a strong reputation for low-temperature heating. Their "Low-H2O" range is specifically designed for heat pump and low-energy systems. Known for quiet operation and sleek design. Available through specialist merchants and heat pump installers.

Myson

Well-established UK brand offering a range of fan convectors at competitive prices. Their "iVector" range is popular for domestic heat pump installations. Widely available and well-supported in the UK market.

Biddle

Dutch manufacturer with a range of fan convectors from compact domestic units to large commercial models. Known for robust construction and reliable performance.

Sabiana

Italian manufacturer offering premium fan convectors with very low noise levels. Their domestic range includes some of the quietest units available.

Smith's Environmental Products

UK-based manufacturer offering fan convectors, trench heaters, and plinth heaters. Good range of domestic-scale products at reasonable prices.

Installation Considerations

Electrical Connection

Fan convectors need an electrical supply for the fan. This is typically a standard 13A plug socket or a fused spur connection. Your installer should plan the electrical connection during the design stage — it is usually a simple addition but needs to be included in the quote.

Controls Integration

Fan convectors should be integrated with the heat pump's control system. Options include:

  • Built-in thermostat: The fan speed adjusts automatically based on room temperature
  • External thermostat: A room thermostat controls both the heat pump and the fan convector
  • Smart controls: Some models integrate with smart home systems for zone-by-zone control

The fan should only run when the heat pump is delivering warm water. Most modern fan convectors have a built-in aquastat (water temperature sensor) that prevents the fan from running when the water is cold, avoiding an uncomfortable cold draught.

Pipework

Fan convectors connect to standard central heating pipework (15mm or 22mm copper or plastic). If you are replacing an existing radiator, the existing connections can usually be used. Ensure the system is properly flushed and treated with corrosion inhibitor, as fan convectors have narrow waterways that can be affected by sludge.

Maintenance

Fan convectors require slightly more maintenance than standard radiators:

  • Filter cleaning: Most units have a washable filter that should be cleaned every 3–6 months to maintain airflow and efficiency
  • Fan motor: Quality units have brushless motors that require no maintenance. Cheaper units with brushed motors may need replacement after 8–10 years
  • Heat exchanger: Periodic vacuum cleaning of the fins prevents dust build-up that reduces output

These tasks are simple and can be done by the homeowner — no specialist tools required.

Fan Convectors vs Other Alternatives

Fan Convectors vs Larger Standard Radiators

If you have the wall space, a larger standard radiator is simpler, cheaper, and silent. Choose a fan convector only when wall space prevents fitting a standard radiator large enough. For most rooms in most homes, a standard Type 22 double-panel convector is the right answer.

Fan Convectors vs Underfloor Heating

Underfloor heating is more efficient (operates at 30–35°C) and completely invisible. But retrofitting underfloor heating is expensive (£1,000–£3,000 per room), disruptive, and raises floor levels. Fan convectors are a more practical retrofit solution for existing homes.

Fan Convectors vs Running the Heat Pump Hotter

The alternative to upgrading radiators is running the heat pump at a higher flow temperature (55°C instead of 45°C). This avoids the cost of new radiators but reduces heat pump efficiency by 15–25%, adding £150–£300 per year to electricity bills. Over 15–20 years, the fan convector often pays for itself through lower running costs.

Frequently Asked Questions

Are fan convector radiators noisy?

Modern fan convectors are surprisingly quiet. On low speed, they produce 22–28 dB — barely audible in a normal room. On medium speed, 28–35 dB — similar to a quiet fridge. Most units spend the majority of their operating time on low or medium speed. High speed (35–42 dB) is only needed during rapid warm-up.

How much do fan convectors cost?

Expect to pay £300–£800 for the unit, plus £150–£450 for installation including the electrical connection. Total cost per fan convector is typically £450–£1,000 fully installed — roughly double the cost of a standard radiator.

Do fan convectors use a lot of electricity?

No. The fan uses 5–30 watts (comparable to a light bulb). Over a full heating season, each fan convector adds roughly £5–£15 to your electricity bill. This is far outweighed by the energy savings from running your heat pump at a lower, more efficient flow temperature.

Can fan convectors provide cooling as well as heating?

Some models can, if your heat pump is capable of producing chilled water (many modern heat pumps have a cooling mode). The fan convector operates in reverse, blowing room air over the chilled coil. This is a growing feature in the UK market as summers become warmer.

Where should I put fan convectors?

Use them in rooms where standard radiators cannot be fitted large enough — typically living rooms, kitchens, and open-plan areas. Avoid bedrooms if you are sensitive to fan noise (even though modern units are very quiet). Standard silent radiators are usually preferable for sleeping spaces.

Do I need fan convectors in every room?

Almost certainly not. Most homes only need fan convectors in 1–3 rooms where wall space or heat demand makes standard radiators impractical. The remaining rooms can use standard double-panel convector radiators. Let the room-by-room assessment determine where they are needed.

How long do fan convectors last?

The heat exchanger element lasts as long as any standard radiator (25+ years). The fan motor in a quality unit (brushless motor) should last 15–20 years with minimal maintenance. Budget units with brushed motors may need fan replacement after 8–10 years.

Summary

Fan convector radiators are a powerful tool in the heat pump installer's toolkit. They deliver exceptional heat output from a compact unit at the low flow temperatures that make heat pumps most efficient. They are not needed in every room or every home, but where wall space is limited, heat demand is high, or maximum efficiency is the goal, they are the best solution available.

If your installer recommends fan convectors for specific rooms, it is worth understanding why — and this guide should give you the knowledge to have that conversation confidently. The right combination of standard radiators and fan convectors, tailored to each room, is what makes a heat pump installation truly perform.