The SPC iTwelve is a low temperature hydronic radiant heating and cooling panel for industrial and large commercial spaces. Built from a copper and aluminium construction with patented “D” shaped 12mm copper tubes, it delivers higher heat output at lower weight than conventional steel tube industrial panels, and is engineered to operate efficiently with heat pumps.
Panel configurations are designed by SPC to match each project’s output requirements, pressure drop constraints, and piping configuration.
How iTwelve Works
The 12mm copper primary tubes are flattened into a “D” shaped profile, wrapped in aluminium saddles, and adhered to a 1mm aluminium radiating panel. This gives 360° contact between the copper tube and the panel surface, minimising heat transfer resistance and the temperature drop between the hot water and the radiating surface.
The downward-facing radiating surface is powder coated white to RAL 9016 to maximise radiant emissivity, while the upper surface carries an insulated blanket to reduce upward convective losses. Output is approximately 70 to 75% radiant and 25 to 30% convective, delivering heat directly to objects and occupants rather than warming the space air. This reduces stratification and lowers overall heat losses from the building, and space air temperature can be held several degrees lower than with a convective system while achieving the same resultant comfort.
The iTwelve can also be used for cooling when connected to a reversible heat pump, with chilled water temperature held above the dewpoint of the space air to prevent condensation on the panel surface.
Where iTwelve Panels Are Used
iTwelve suits large commercial and industrial spaces where ceiling-level radiant heating is the preferred solution, including:
- Sports halls and leisure centres (reinforced variant available, see below)
- Aircraft hangars
- Warehouses and distribution centres
- Manufacturing and assembly facilities
- Logistics and e-commerce fulfilment centres
- Workshops and service bays
- Other large commercial buildings with high-bay areas
Panel runs can extend along the full length of a building, with single water circuits typically practical up to 40m. For longer runs, multiple circuits can be piped in parallel, with run length limited only by the building itself.
Key Benefits
- Lightweight: a 3m iTwelve module weighs approximately 5.5kg dry, compared to around 20kg for an equivalent conventional steel tube panel
- Heat pump compatibility: efficient operation at low water temperatures supports the move away from direct fired equipment and reduces on-site emissions
- Fewer on-site connections: patented tube manifolding means each run needs only a single final connection pipe per panel, reducing on-site joints to typically less than half the quantity required for conventional steel tube panels
- Simple hanging system: panels are suspended via multi-suspension bars, carabiner hooks, and wire, with no need for rigid threaded bar arrangements
- Heating and cooling from one system: subject to chilled water temperature being held above the space dewpoint
- Bespoke design support: SPC handle output calculations, pressure drop modelling, and connection positioning for every project
Technical Specification
| Feature | Detail |
| Primary tube | 12mm copper, “D” profile, 0.35mm wall thickness |
| Final panel connection | 22mm copper tail |
| Radiating panel | 1mm edge-flanged aluminium, adhered via 0.5mm aluminium saddles, white RAL 9016 |
| Surface emissivity | 0.95 |
| Panel widths | 300mm modules, hung in parallel up to four wide (300, 600, 900, 1200mm effective widths) |
| Panel length | Up to 3m, joined end to end for longer runs |
| Maximum single-circuit run | Approximately 40m (longer runs achievable in parallel) |
| Maximum working pressure | 6 bar |
| Maximum working temperature | 85°C |
| Radiant/convective split | Approximately 70 to 75% radiant, 25 to 30% convective |
| Connections | 22mm copper crimp connectors or push-fit flexible hoses, no welding required |
| Insulation | 25mm foil-backed as standard |
Heat Output
Output varies with excess temperature, the difference between mean hot water temperature and room air temperature. Figures below are a guide, in watts per square metre; SPC calculates precise outputs and pressure drops at the design stage.
| Excess Temperature (°C) | Heat Output (W/m²) |
|---|---|
| 15 | 154 |
| 20 | 216 |
| 25 | 281 |
| 30 | 349 |
| 35 | 419 |
| 40 | 490 |
| 45 | 563 |
| 50 | 639 |
| 55 | 715 |
Sports Hall Variant
A dedicated sports hall panel variant is available, built to comply with DIN 18032-3, including resistance to bombardment from sporting equipment. It features a fully folded construction with pipe connections hidden behind the panel, and optional domed mesh ball guards fitted after installation.
SPC Design Support
Every iTwelve project receives support from SPC, from the earliest stages of design, including technical consultation and site visits, output calculations and pressure drop modelling, piping configuration assistance, and support with logistics, delivery, and installation.
Ongoing after-sales support is provided once the system is running. CIBSE-approved CPD sessions on the Decarbonisation of Industrial and Commercial Heating Systems are also available.
Frequently Asked Questions
It’s a low temperature hydronic radiant heating and cooling panel using 12mm copper “D” profile tubes bonded to a 1mm aluminium radiating panel, delivering high thermal output at lower weight than conventional steel tube panels.
Yes. It’s designed to operate at the low flow temperatures produced by heat pump generators, supporting industrial sites reducing or eliminating on-site fossil fuel combustion.
Yes. Connected to a reversible heat pump, the iTwelve can provide radiant cooling, with chilled water temperature kept above the dewpoint of the space air to prevent condensation.
Panels are supplied in 300mm width modules and up to 3m lengths, hung in parallel up to four wide for effective widths of 300, 600, 900, or 1200mm. Individual panels connect in series along the building length, with single circuits typically practical up to 40m.
The iTwelve has a maximum working pressure of 6 bar and a maximum working temperature of 85°C.
No. Panels connect via 22mm copper crimp connectors or push-fit flexible hoses, with no welding required on site.
Yes. A sports hall variant complies with DIN 18032-3, with a fully folded construction, hidden pipe connections, and optional domed mesh ball guards.
