GLN Specify GLN

1Overview

Radiant panels for buildings that have to stay quiet

GLN heats and cools rooms by radiation. An outdoor heat pump conditions the water; slim aluminium-fin panels bring the room’s surfaces to temperature. The system has no vents and no ducts, and indoors there is no fan and no compressor.

This guide is for the people who specify it: rated output, the system schematic, reference projects, specification tables, CAD and BIM files, and a direct line to an application engineer in Wuhan.

See rated output Download drawings

At a glance

Heat transfer
Radiation between the panel and the room’s surfaces. No air is blown at anyone.
Indoors
No fan and no compressor. The compressor sits in the outdoor heat pump.
Pipework
Never on the wall. Supply and return come down inside the wall from the ceiling and join the panel at one fitting.
Condensation
No condensation water appears indoors.
Ceiling void 1800 150 600 Front elevation 90 A Supply and return in ceiling void Pipes in a wall chase Single fitting Aluminium-fin panel Wall bracket Section 25 A
Maker
GLN
Title
RP-18 radiant panel. Elevation, section, detail A
Drawing
RP-18-01
Rev
C
Scale
NTS
Units
mm
RP-18 panel, 600 × 1800 × 90 mm. Detail A: fins 1.2 mm at 25 mm pitch, 12 mm water tube.
Cooling per RP-18 panel at ΔT 10 K
420W
Heating per RP-18 panel at ΔT 12.5 K
510W
From the wall to the front edge
90mm
Felt temperature with air at 27 °C and walls at 22 °C
24.5°C

Demo data. Felt (operative) temperature is roughly the mean of air and surface temperature, as in ASHRAE 55 and ISO 7730.

2Performance

Output per panel against the mean water-to-room temperature difference. Pick a mode and a panel height, then drag on the chart or use the slider.

Mode
Panel height
12.5 K

The interactive chart needs JavaScript. The table below lists the same output values.

Demo data Curves follow Q = K · ΔTn, the characteristic-equation form used in EN 442 ratings, with n = 1.25. Shaded band: typical design range.
Output per panel in W, heating mode
ΔT (K)RP-121200 mmRP-181800 mmRP-242400 mm
5.0110162211
7.5183269350
10.0262386502
12.5347510663
15.0436641833
20.06249181,193
25.08251,2131,577

Rating conditions

Cooling
Water 16/18 °C, room 27 °C, mean ΔT 10 K. Exponent n = 1.10.
Heating
Water 35/30 °C, room 20 °C, mean ΔT 12.5 K. Exponent n = 1.25.
Mounting
On a solid wall, 150 mm above the floor, no enclosure.

The rated row is marked. Outputs for other heights scale with face area and are listed for layout only. Test reports are in 6 Downloads.

3System

One outdoor heat pump, a buffer tank, a manifold and a panel circuit per room. Select a component in the schematic to see its data.

Mode
  • Supply
  • Return
  • Concealed in wall
Outdoor heat pump HP-16 Buffer tank Circulator Manifold Pipes in the wall Single fitting Radiant panel RP-18 Room controller
Schematic: outdoor heat pump, buffer tank and circulator, manifold, then one supply and one return per panel, running in the ceiling void and down inside the wall to a single fitting on each panel.

Outdoor heat pump

Air-to-water heat pump outside the building. It warms or cools the water, and it holds the only compressor in the system.

Heating capacity, A7/W3516.0kW
Cooling capacity, A35/W1814.0kW
Supply water, heating30–45°C
Supply water, cooling16–20°C
RefrigerantR290

Buffer tank

Separates the heat pump circuit from the room circuits and evens out short run times.

Volume100L
Insulation50mm
Connections4 × DN32
Maximum pressure6bar

Circulator

Variable-speed pump for the room circuits, sized to the longest circuit.

Maximum head6.0m
Maximum flow3.2m³/h
Electrical input4–45W

Manifold

One supply and one return port per panel circuit, each with a flow meter and a 24 V actuator.

Circuits2–12
Header sizeDN25
Flow meter range0.5–5.0L/min
Actuator supply24V AC

Concealed pipework

Supply and return run in the ceiling void and drop inside the wall. Nothing runs on the wall face.

Pipe, PE-RT16 × 2.0mm
Insulation, closed cell9mm
Wall chase for the pair60 × 35mm

Single fitting

Supply and return join the panel at one fitting on its top edge, with an isolating valve on each port.

Connection2 × 12mm
Port spacing40mm
BodyNickel-plated brass

Radiant panel RP-18

Aluminium-fin panel, 600 × 1800 × 90 mm. Its surface settles near the water temperature and exchanges heat with the room by radiation.

Cooling at ΔT 10 K420W
Heating at ΔT 12.5 K510W
Dry weight21.0kg
Water content1.4L

Room controller

Measures air and surface temperature and controls each zone to felt temperature.

Setpoint range16–30°C
Sensor accuracy±0.3K
Output to actuators24V AC
InterfaceModbus RTU

4References

Completed projects in Wuhan and Hubei, a hot-summer, cold-winter climate where one system has to do both jobs.

12 projects

  • Open-plan office with floor-to-ceiling glass, a long table and a polished concrete floor Illustrative

    Office

    Riverside office tower, floors 8 to 14

    Wuhan, Hankou

    Area
    9,400m²
    Panels
    1,020
    Completed
    2025
  • Office corridor lined with black-framed glass partitions Illustrative

    Office

    Software park, building C

    Wuhan, Optics Valley

    Area
    6,200m²
    Panels
    640
    Completed
    2024
  • Classroom with desks and a corner of large windows onto autumn trees Illustrative

    School

    Primary school, north wing

    Jingzhou

    Area
    4,100m²
    Panels
    372
    Completed
    2025
  • Hotel reception desk in front of a curved wall of golden wood panels Illustrative

    Hotel

    City hotel, lobby and 180 rooms

    Wuhan, Jianghan

    Area
    11,600m²
    Panels
    1,140
    Completed
    2025
  • White waiting area with curved benches and a small tree planted in gravel Illustrative

    Clinic

    Rehabilitation day centre

    Huangshi

    Area
    2,700m²
    Panels
    246
    Completed
    2025
  • Glass-walled meeting room with upholstered chairs around a long table Illustrative

    Office

    Law chambers, level 21

    Wuhan, Wuchang

    Area
    2,150m²
    Panels
    214
    Completed
    2025
  • Hotel lobby with a marble reception counter, wood-slatted wall and planters Illustrative

    Hotel

    Lakeside hotel, lobby and spa

    Wuhan, Donghu

    Area
    3,900m²
    Panels
    330
    Completed
    2024
  • Dim lecture room with rows of wooden desks and blinds half drawn Illustrative

    School

    University lecture hall block

    Wuhan, Hongshan

    Area
    3,300m²
    Panels
    286
    Completed
    2024
  • Bright clinic corridor with teal waiting chairs and a white coat stand Illustrative

    Clinic

    Family clinic, two floors

    Wuhan, Qiaokou

    Area
    1,450m²
    Panels
    132
    Completed
    2024
  • Glass curtain-wall façade reflecting the sky Illustrative

    Office

    Design institute headquarters

    Xiangyang

    Area
    12,800m²
    Panels
    1,310
    Completed
    2024
  • Tall hotel lobby with a brass chandelier, stone walls and low sofas Illustrative

    Hotel

    Riverfront hotel, public floors

    Yichang

    Area
    5,200m²
    Panels
    468
    Completed
    2023
  • Pale green consulting room with a desk, two chairs and a botanical window blind Illustrative

    Clinic

    Specialist consulting suite

    Wuhan, Wuchang

    Area
    620m²
    Panels
    58
    Completed
    2025

5Specification

Values for the RP series and the parts around it. Copy them into your specification, or download the tender text in 6 Downloads.

Panel

RP series, dimensions and rated output
ParameterRP-12RP-18RP-24Unit
Height120018002400mm
Width600600600mm
Depth, wall to front edge909090mm
Face area0.721.081.44m²
Dry weight14.521.027.5kg
Water content0.91.41.9L
Cooling output, ΔT 10 K286420546W
Heating output, ΔT 12.5 K347510663W
Exponent n, cooling / heating1.10 / 1.251.10 / 1.251.10 / 1.25
Fin profile
Extruded aluminium, fins 1.2 mm thick at 25 mm pitch behind a flat front plate.
Water circuit
12 mm copper tube pressed into the profile channel.
Finishes
Chalk (matt white), Graphite (matt dark grey), Natural anodised. Other RAL colours to order.

Hydraulics

Hydraulic data, RP-18 unless noted
ParameterValueUnitCondition
Maximum operating pressure6barAll models
Factory test pressure9barEach panel
Supply temperature, heating30–45°CFrom the heat pump
Supply temperature, cooling16–20°CFrom the heat pump
Nominal flow, heating88L/h5 K water ΔT
Nominal flow, cooling181L/h2 K water ΔT
Pressure drop, heating1.8kPaAt nominal flow
Pressure drop, cooling7.4kPaAt nominal flow
Connection
One fitting on the top edge with two 12 mm compression ports and isolating valves.
Distribution
One circuit per panel from the manifold, PE-RT 16 × 2.0 mm, insulated.

Controls

Room controller and manifold actuators
ParameterValueUnitCondition
Setpoint range16–30°CFelt temperature
Sensor accuracy±0.3KAir and surface
Actuator supply24V ACNormally closed
Actuator power1.0WPer circuit
Actuator opening time3minFull stroke
Circuits per manifold12Maximum
Control variable
Felt (operative) temperature, from an air sensor and a surface sensor in each controller.
Mode changeover
Central, at the heat pump. Rooms follow the building mode.
Interfaces
Modbus RTU on the controller; BACnet MS/TP through a gateway.

Installation

Clearances and site data, RP series
ParameterValueUnitCondition
Height above floor150mmTo the panel bottom
Side clearance50mmMinimum
Clearance to ceiling100mmMinimum
Wall chase for the pipe pair60 × 35mmWidth × depth
Brackets per panel4Anchors to suit the wall
Site pressure test9bar30 min, before plastering
Fitting time per panel45minSecond fix, two fitters

Sequence on site

  1. First fix: run the pipe pair in the ceiling void and down the wall chase; cap it at the fitting position.
  2. Pressure test the circuit.
  3. Plaster and finish the wall.
  4. Second fix: brackets, panel and the single fitting.
  5. Fill, vent, and set the flow for each circuit at the manifold.

6Downloads

Drawings, models and documents for design and tender. Files are demo placeholders on this page.

Downloadable files
DocumentFormatSizeSize unitRevAction
CAD details: wall mounting and pipe dropDWG2.4MBCDownload
CAD details: panel elevations, RP-12 to RP-24DWG, DXF1.1MBCDownload
BIM family: RP panels, Revit 2024 and laterRFA3.8MBBDownload
BIM object: RP panelsIFC 42.2MBBDownload
Data sheet: RP seriesPDF860KBCDownload
Installation guidePDF4.6MBCDownload
Test report: heating outputPDF1.3MBADownload
Test report: cooling outputPDF1.2MBADownload
Specification text for tender documentsDOCX64KBCDownload

7Talk to an application engineer

Send what you have: a plan, a load estimate, a question about pipe routes. An engineer in Wuhan checks panel counts and layout and replies within one working day.