LC80 Fan-Assisted Convector

STEKON LC80 Fan-Assisted Trench Convector Heating Capacity

The STEKON LC80 fan-assisted trench convector is a low-profile hydronic heating unit designed for floor installation, particularly in front of large glazed façades and floor-to-ceiling windows. Its heating capacity depends on the unit length, casing width, water supply/return temperatures and fan speed.

LC80 heating performance has been independently tested in accordance with EN 16430, the European standard for fan-assisted and natural convection trench convectors. The tests were carried out by HEATEST, an ISO/IEC 17025 accredited laboratory (Test Report No. 017/2026).

The heating capacities published below are the actual values obtained from these independent laboratory tests.

LC80 Dimensions

The LC80 range combines a shallow 80 mm installation height with different casing widths, allowing the heating capacity to be adapted to the available floor space and project heat load.

LC80 Heating Capacity at 75/65 °C

Water temperatures: 75/65 °C
Room temperature: 20 °C
Capacity: W

These values can be used for conventional boiler systems, condensing boilers and central hot-water heating systems operating close to a 75/65 °C design regime.

LC80 Heating Capacity at 55/45 °C

The STEKON LC80 can also operate effectively in low-temperature heating systems, including modern heat pump applications.

Water temperatures: 55/45 °C
Room temperature: 20 °C
Capacity: W

Can the STEKON LC80 Be Used with a Heat Pump?

Yes. The STEKON LC80 fan-assisted trench convector is suitable for heat pump heating systems.

Because the LC80 uses integrated fans to increase airflow through the heat exchanger, it can maintain useful heating capacities at lower water temperatures than conventional natural-convection heating terminals.

This makes the LC80 particularly suitable for:

• air-to-water heat pumps

• R290 heat pumps

• low-temperature heating systems

• condensing boiler systems

• hybrid heating systems

• underfloor heating systems requiring additional perimeter heating

• buildings with large glazed façades and high façade heat losses

Modern R290 (propane) monobloc heat pumps can operate with relatively high supply water temperatures, making water regimes such as 55/45 °C practical for many heating applications.

For trench convector selection, this is important because operating at 55/45 °C allows significantly more heating capacity to be retained than at very low-temperature regimes such as 45/35 °C.

LC80 Capacity at Different Water Temperatures

As the water temperature decreases, trench convector output also decreases. Therefore, the unit must always be selected according to the actual design water temperatures of the heating system.

Example: Selecting an LC80 for a Heat Pump System

Consider a 2000 mm long STEKON LC80-240 operating at maximum fan speed.

At:

75/65/20 °C → Heating capacity: 2,359 W

At:

55/45/20 °C → Heating capacity: 1,371 W

The same unit therefore provides approximately 58% of its 75/65 °C output when operating at 55/45 °C.

If the room heat loss remains unchanged, the reduced water temperature must be compensated for by:

• increasing the trench convector length,

• selecting a wider LC80 model,

• or using multiple units.

For example, a 2000 mm LC80-300 provides 1,766 W at 55/45/20 °C.

In many projects, selecting the wider 300 mm casing can therefore be more practical than significantly increasing the convector length.

Why Are Fan-Assisted Trench Convectors Suitable for Heat Pumps?

Heat pumps are most efficient when operating with relatively low water temperatures. However, reducing the water temperature also reduces the output of conventional radiators and natural-convection trench heaters.

A fan-assisted trench convector increases airflow through the heat exchanger and improves heat transfer between the water circuit and the room air.

For this reason, fan-assisted trench convectors can provide considerably higher heating outputs at low water temperatures than equivalent natural-convection units.

The LC80 therefore offers an effective solution where a heat pump system must also compensate for heat losses around:

• floor-to-ceiling glazing,

• curtain wall façades,

• large windows,

• glazed entrances,

• perimeter zones.

Fan-Assisted or Fanless Trench Convector for a Heat Pump?

For low-temperature and heat pump applications, a fan-assisted trench convector is generally the preferred solution.

Natural-convection models depend mainly on the temperature difference between the heat exchanger and room air. As the heating water temperature decreases, natural convection becomes weaker and the available heating capacity drops significantly.

The integrated fans in the STEKON LC Series increase airflow through the heat exchanger and help maintain useful heating capacity even at lower water temperatures.

For this reason, the LC Series is recommended instead of fanless SC Series models when trench convectors are used with heat pumps, provided the project requirements allow fan-assisted operation.

Can the LC80 Be Used Together with Underfloor Heating?

Yes.

The STEKON LC80 can be used together with an underfloor heating system, including systems supplied by a heat pump.

This combination can be particularly useful in buildings with large glazed façades.

Underfloor heating provides the general room heating load, while trench convectors installed along the glazed façade can provide additional perimeter heating to:

• compensate for façade heat losses,

• reduce cold downdraught near glazing,

• improve thermal comfort close to windows,

• and increase heating capacity where the underfloor heating system alone is insufficient.

The trench convector must still be selected according to the actual water temperatures available in the circuit.

0–10 V Control for Modulating Heat Pump Systems

STEKON LC Series trench convectors support 0–10 V proportional fan speed control.

The EC fans can therefore adjust their speed according to the room temperature, thermostat demand or building management system signal.

This allows the trench convector output to respond progressively to changing room loads rather than operating only in simple ON/OFF mode.

In a properly designed system, proportional control can provide:

• more stable room temperatures,

• reduced unnecessary fan operation,

• improved acoustic comfort,

• better part-load operation,

• and easier integration with building automation systems.

How Should a Trench Convector Be Selected for a Heat Pump?

A heat pump trench convector should never be selected only from conventional 75/65 °C heating capacity data.

The following parameters should be considered:

1. Room design heat loss

2. Heat pump supply and return water temperatures

3. Room design temperature

4. Available trench length

5. Available trench width and installation depth

6. Required fan speed

7. Acoustic requirements

8. Control strategy

For example, if the heat pump operates at 55/45 °C, the LC80 must be selected directly from the 55/45 °C capacity data rather than from the 75/65 °C table.

This prevents undersizing and ensures that the required room heating load can be met under actual operating conditions.

Is the STEKON LC80 Tested According to EN 16430?

Yes.

The thermal performance of the STEKON LC80 fan-assisted trench convector has been independently tested according to EN 16430.

The tests were performed by HEATEST, an ISO/IEC 17025 accredited test laboratory, under Test Report No. 017/2026.

The heating capacity figures published by STEKON correspond to the results of these tests.

This provides engineers, consultants and HVAC designers with independently verified performance data for product selection.

LC80 Key Technical Features

• Fan-assisted hydronic trench convector

• 80 mm casing height

• 200 mm, 240 mm and 300 mm casing width options

• Suitable for heating applications

• Suitable for heat pump and low-temperature heating systems

• Performance tested according to EN 16430

• Independent testing by an ISO/IEC 17025 accredited laboratory

• 24 V DC EC fan technology

• 0–10 V proportional fan control

• Suitable for installation in front of large glazed façades

• Compatible with building automation systems

LC80 Selection for Heat Pump Projects

For heat pump applications, always select the LC80 according to the project's actual supply and return water temperatures.

A unit selected at 75/65 °C may not provide sufficient heating capacity when connected to a heat pump operating at 55/45 °C or 45/35 °C.

Use Smartstep Selection to enter the actual project water temperatures and determine the appropriate STEKON LC80 model, width and length for the required heating capacity.