Complete product data.
Full profile specifications, EN 442-1 heat-output tables across every flow temperature, an interactive sizing calculator, run-length limits and the complete wet and electric range, one authoritative reference for specifying ThermaSkirt.
One component that replaces the radiator and the skirting board.
ThermaSkirt is an aluminium radiant heating panel built into a 20 mm-thick skirting profile. Water (or a self-regulating electric element) runs the length of the room at the perimeter, emitting low-temperature radiant heat where rooms lose it, along external walls and into cold corners.
Because it is sized linearly against the room's available perimeter rather than as a single point emitter, it holds a high proportion of its output at heat-pump flow temperatures. Every figure on this page is calculated per EN 442-1, factored on BSRIA test 51397-1.
- Two primary wet profiles: Deco BM2 (114 mm) and BM3 (170 mm), both 20 mm thick, replacing the radiator and the skirting board in one component.
- Nominal output (EN 442-1, 75/65/20): 125.7 W/m (BM2) and 188.34 W/m (BM3).
- At a 45/40 heat-pump design (MWT 42.5 °C): ~58 W/m (BM2) and ~83 W/m (BM3) in a 20 °C room.
- Low water volume of 0.48 L/m (BM2) and 0.72 L/m (BM3), giving radiator-comparable response, far faster than underfloor heating.
- Single-feed run limits: 20–25 m (BM2) and 15–20 m (BM3) per 15/16 mm feed.
- CE marked to BS EN 442-1; tested by BSRIA (UK), KTH/TÜV (Germany) and TSE (Turkey).
- 10-year warranty on wet parts; 5-year on electric elements. UK manufactured, 85,000+ systems over 18+ years.
Which wet profiles are available?
Two profiles cover the residential heat-loss range. Both are a 20 mm-thick aluminium polymer alloy with a double epoxy powder coat. A taller BM4 specials profile is available for exceptional heat loss.
| Specification | Deco BM2 | Deco BM3 |
|---|---|---|
| Height × thickness | 114 × 20 mm | 170 × 20 mm |
| Weight | 1.36 kg/m | 2.04 kg/m |
| Water volume | 0.48 L/m | 0.72 L/m |
| Nominal output (75/65/20) | 125.7 W/m | 188.34 W/m |
| EN 442 coefficient Km | 1.128 | 1.907 |
| EN 442 exponent n | 1.2245 | 1.1714 |
| Standard lengths | 1.5 / 3.0 / 4.5 m | 1.5 / 3.0 / 4.5 m |
| Operating / test pressure | 1.5–3 / 10 bar | 1.5–3 / 10 bar |
6.0 m lengths and made-to-measure available to order. Connectors: oval 10 mm (12 mm EU/USA) and oval 15 mm (16 mm EU/USA), with TRV/lockshield kit.
What heat output does each profile deliver?
Output is published per linear metre against mean water temperature (MWT, the average of flow and return) in a 20 °C room. To read off a heat-pump design, use the flow/return pairs in the second table.
| Mean water temp | BM2 (W/m) | BM3 (W/m) |
|---|---|---|
| 35 °C | 31 | 46 |
| 40 °C | 44 | 64 |
| 45 °C | 58 | 83 |
| 50 °C | 73 | 102 |
| 55 °C | 88 | 123 |
| 60 °C | 103 | 144 |
| 65 °C | 119 | 165 |
| 70 °C | 136 | 186 |
| 75 °C | 153 | 208 |
Output at common flow / return design points
| Flow / return | Application | MWT | BM2 (W/m) | BM3 (W/m) |
|---|---|---|---|---|
| 75 / 65 °C | Gas / oil boiler | 70 °C | 136 | 186 |
| 55 / 45 °C | Heat pump (high) | 50 °C | 73 | 102 |
| 45 / 40 °C | Heat pump (ΔT20) | 42.5 °C | 51 | 73 |
| 40 / 35 °C | Heat pump (low) | 37.5 °C | 38 | 55 |
All outputs per linear metre in a 20 °C room, calculated per EN 442-1 (BSRIA test 51397-1).
Size a room in seconds.
Enter a room's heat demand or its available wall run and a design flow temperature. The calculator returns the metres of each profile required (or the output available over your run), recommends a profile, and flags where a run exceeds a single feed.
15.7 m of Deco BM2 on a single feed.
What length replaces a radiator?
A 1200 × 600 Type 22 panel radiator at ~40 °C mean water temperature emits roughly 632 W. At the same mean water temperature ThermaSkirt delivers ~44 W/m (BM2) and ~64 W/m (BM3).
So that single radiator is equivalent to about 14 m of BM2 or 10 m of BM3, distributed around the room perimeter instead of stacked on one wall. On a heat pump this avoids the oversized K3 radiators that low flow temperatures would otherwise demand.
What are the run-length and pipework limits?
Maximum continuous run per feed depends on profile and feed-pipe size. Beyond these lengths, split the room across multiple feeds or zones to maintain flow rate and even output.
| Profile | Per 15 / 16 mm feed | Per 10 mm (microbore) feed |
|---|---|---|
| Deco BM2 | 20–25 m | 15 m |
| Deco BM3 | 15–20 m | 12–15 m |
| Deco BM4 | 10–15 m | 6–8 m |
ThermaSkirt-e (electric)
The electric range uses a self-regulating heating cable that cannot exceed its rated temperature even when covered. Three cable grades (FS30 / FS45 / FS60) cover the UK heat-loss range; output is selected against the SAP/PHPP calculation. ThermaCurve is a curved coving variant for cornice-level heating.
| Model | Height | FS30 | FS45 | FS60 | Max run |
|---|---|---|---|---|---|
| Deco BMe2 | 114 mm | 50–65 | 85–95 | 115–130 | 25 m (13 A) |
| Deco BMe3 | 170 mm | 80–95 | 120–130 | 140–185 | 15 m (13 A) |
| Deco BMe4 | 230 mm | 100–130 | 170–190 | 230–260 | 25 m (2 × 13 A) |
| ThermaCurve | 115 mm | 80–95 | 120–130 | 140–185 | 15 m (13 A) |
Output bands W/m by cable grade. Supply 220–240 V; protection Type C 30 mA RCBO; CE marked to the Low Voltage Directive, tested to EN 60335-2-30, EMC certificate C1064575. 5-year element warranty.
Add2Rad and EasyClean
Add2Rad
A series supplement that plumbs into an existing radiator circuit to top up output, up to ~90 W/m at 45 °C, around 360 W from a typical 4 m run. Installs in under an hour per room, making it a fast retrofit fix for a heat-pump shortfall without re-piping.
EasyClean
The standard BM2/BM3 emitter fitted with an anti-ligature, anti-tamper capping for healthcare, custodial and SEND environments. It is a capping option on the same profile, not a separate product, so the output data above still applies.
Warranty & certification
The 10-year wet warranty is conditional on correct water treatment for the aluminium emitter, see the Water Treatment Protocol.
Everything you need to know
How is ThermaSkirt heat output calculated?
Is the output quoted at flow temperature or mean water temperature?
How do I size a room?
What length of ThermaSkirt replaces a radiator?
What is the run-length limit per feed?
What is the rated output of the electric range?
Does the aluminium emitter need special water treatment?
Explore related Technical Data
How this product data feeds energy modelling, the underlying physics, and the requirements that protect it.
Need a room-by-room schedule?
Send us your floor plans and design flow temperature. Our engineering team returns a free, room-by-room heat-loss schedule with ThermaSkirt sized profile-by-profile.