trench heating technical specs
Perimeter Casing
Warmline Trench Heating
Fan Coil Casings
Fan Assisted Convectors
Spirally Wound All Steel Gilled Tube

Technical Details

If the technical details below don’t answer your heating questions then please get in touch and we will do our best to help you. Contact us here.


The above outputs are for casings fitted with aluminium linear grille.

1. The outputs are based one the following conditions: Mean water temperature 76.5ºC, Ambient temperature 18.0 ºC, Water velocity 0.92m/s

2. Single finned tube plus plain pipe. Apply factor 1.04. Output from one of two plain pipes only within casing. ( Mean Water temperature 76.5 ºC)

15mm pipe 22mm pipe 28mm pipe 35mm pipe
(w/m) (w/m) (w/m) (w/m)
1 Pipe 30 40 50 60
2 Pipes 50 70 90 110

(one over the other)

3. Heat outputs derived from tests in accordance with EN442. For outputs on different operating conditions, element configurations or diameter of tube please contact our sales office on

4. The ECU range of elements are constructed from 0.25mm aluminium with closed sides to 86mm elevation of the fin, the copper tube is expanded into collars in the centre of the fins and one end of the tube is expanded to provide a female socket to BS864, the other end is plain tube to BS2871 part 1. The tube is suitable for both end feed and compression fittings.

5. The WSCU and XCU elements are constructed from 0.5mm aluminium. The fins are open on all sides, the tube is suitable for both end feed and compression fittings.

6. The WSCU and XCU range of elements have the facility of varying the fin spacing thus allowing the heat output to be drawn out over a larger area if required. Please ask our technical department for details.


Given the following: Window mullions module 1200 mm, sill height 600 mm, water temperatures 82/71 ºC, ambient temperature 21ºC, heat loss in room 5450w, available wall length 9.6m.

Casing style Sill Line Sloping. All pipework within casing. Output per metre is (5450w/9.6m)= 568w/m. The flow rate at a temperature drop of 11ºC will be 5450/(4180 x 11) = 568w/m min. At this flow rate 22mm ECU elements would be used. (The specific heat of water is 4180j/kg. From table 1, output from 500mm high Sill Line Sloping Casing is 810w/m exceeding the minimum requirement. The approximate lenght of the element will be 5450/810=6.73m.

Determine the cumulative factor thus: Mean water temperature 76.5ºC and ambient temperature 21ºC. See table 2 Factor 0.93. Flow rate 0.118kg/s. See Table 3 Factor 0.95. Return pipe within casing Factor 1.04. Therefore the cumulative factor = 0.93 x 0.95 x 1.04 =0.918. The corrected output is 810 x 0.918 = 744 w/m. element now required will be (5450/744) = 7.5m. Element lengths could comprise 3@2000mm and 1@1500mm. Allowing for bare pipe at the element ends this would occupy 8.0m fitting easily in the 9.6m of casing.