KORAFLEX Basic FKB

Heating
Natural convection
Low energy consumption

Depth [mm]	70, 90, 110 mm
Width [mm]	140, 200, 260, 320 a 420 mm
Length [mm]	800 to 3 000 mm (by 100 mm)
Heat output [W]	from 41 to 1 739 W
Max. operating pressure [MPa]	1.2 MPa
Max. operating temperature [°C]	90 °C
Connecting thread	inner G ½"
Cover grilles
	Where a left-hand connection to the heating system is required, rotate the heat exchanger in the trench heater by 180°. Cross grille – design solutions – the casing must undergo alternation. Cross grilles must be ordered together with trench heaters. These trench heaters will be fitted with a Cross frame suitable for a Cross grille.

Heat output [W] where t1/t2/ti / EN 16430. Measurements shown in mm including U-frame.

Inlet temperature in °C

Outlet temperature in °C

Air temperature in °C

ΔT

ΔT = 50 °C		Length [mm]																							Temperature exponent
Depth [mm]	Width [mm]	800	900	1000	1100	1200	1300	1400	1500	1600	1700	1800	1900	2000	2100	2200	2300	2400	2500	2600	2700	2800	2900	3000	Temperature exponent
70	140	42	51	61	71	81	91	101	111	121	130	140	150	160	170	180	190	200	210	219	229	239	249	259	1,4629
70	200	76	90	105	120	135	150	165	179	194	209	224	239	254	268	283	298	313	328	342	357	372	387	402	1,4587
70	260	90	108	126	143	161	179	196	214	232	250	267	285	303	320	338	356	373	391	409	426	444	462	480	1,6148
70	320	102	124	146	168	189	211	233	255	276	298	320	342	364	385	407	429	451	472	494	516	538	559	581	1,5550
70	400	131	157	183	208	234	260	286	311	337	363	389	414	440	466	492	517	543	569	595	620	646	672	698	1,5235
90	140	50	62	74	86	98	110	122	134	146	158	170	182	194	206	218	230	242	254	266	278	290	302	314	1,5247
90	200	120	143	167	191	214	238	261	285	308	332	355	379	402	426	449	473	496	520	543	567	590	614	637	1,5373
90	260	153	183	213	243	273	303	333	363	393	423	453	483	513	543	573	603	633	663	693	723	753	783	813	1,5643
90	320	195	236	278	319	361	402	444	485	526	568	609	651	692	733	775	816	858	899	940	982	1023	1065	1106	1,4599
90	400	275	329	383	437	490	544	598	652	706	760	814	868	922	976	1029	1083	1137	1191	1245	1299	1353	1407	1461	1,4607
110	140	55	69	82	95	108	122	135	148	161	174	188	201	214	227	240	254	267	280	293	307	320	333	346	1,4888
110	200	142	170	198	226	254	282	309	337	365	393	421	449	477	505	532	560	588	616	644	672	700	728	755	1,4739
110	260	184	220	257	293	329	365	401	437	473	510	546	582	618	654	690	726	763	799	835	871	907	943	979	1,4385
110	320	237	287	338	388	438	489	539	589	640	690	740	791	841	891	942	992	1042	1093	1143	1193	1244	1294	1344	1,4622
110	400	327	391	455	520	584	648	712	776	840	905	969	1033	1097	1161	1225	1289	1354	1418	1482	1546	1610	1674	1739	1,4569

Standard contents

hot-dip galvanized steel casing, non-lacquered

non-lacquered Al/Cu heat exchanger with bleed valve

aluminium U-frame, silver elox

metal cover plate

levelling set screws and 4 anchors

spacers for correct installation and concreting

hardboard cover to protect trench heater from contamination

durable packaging, installation instructions

Optional accessories

choice of grilles

Cross grille – design solutions – necessary to order together with trench heater

light/dark bronze and black elox or RAL colour chart lacquered aluminium U-frame

silver, light/dark bronze, black el.or RAL colour chart lacquered aluminium F-frame

thermostatic head with incorporated control and immersion remote sensor

24V DC power supply 60 W, 100 W

room thermostat SIEMENS RAA21 or SIEMENS RDE 100.1

24V DC or 230V AC thermoelectric actuator

raised floor structural supports

lockshield, thermostatic valve, axial thermostatic valve

½" × ½" 90° brass elbow for connection facilitation

flexible connecting hose

strengthened OSB cover for installation purposes

TRENCH HEATER COMPONENTS

1hot-dip galvanized steel casing, non-lacquered

2choice of grille (please order separately)

3choice of aluminium frame

4Al/Cu heat exchanger

54 anchors

6levelling set screws

7metal cover plate

8brackets

9spacers for correct installation and concretin

Suitable grilles

Roll-up aluminium silver	Linear aluminium silver	Roll-up aluminium dark bronze	Linear aluminium dark bronz
Roll-up aluminium light bronze	Linear aluminium light bronze	Roll-up aluminium black elox	Linear aluminium black elox
Roll-up steel	Linear steel	Roll-up stainless steel	Linear stainless steel
Roll-up natural / lacquer beech	Roll-up natural / lacquer oak	Roll-up natural / lacquer mahogany (upon request)
Cross (upon request)	Robust stee/stainless steel (upon request)

Frames

U-frame	F-frame	Cross frame - Lowered casing edge

Decorative U-shaped and F-shaped frames are available as standard in aluminium with silver, black, dark bronze or light bronze elox finishes. U-frame and Cross frames are available also in black elox. Frames may also be lacquered (powder coated) using colours from the RAL colour chart. Frames are in every case supplied as a component of trench heaters, and the type required must be specified when ordering in the Order Code.

FK TRENCH HEATER INSTALLATION

Construction recommendations

To ensure correct operation, it is essential that the following principles are respected.

Trench heaters must be installed horizontally with the heat exchanger on the window side. For the grille to function correctly, the upper edge of the casing must be straight and level (not buckled or bent).
The maximum recommended distance of the trench heater from the wall/window is 100 mm.
The size of the trough in the floor for the trench heater installation should be at least 100 mm bigger (both in length and width) than the convector.
We recommend connecting the trench heater to the heating system using a lockshield and thermostatic valve. The heat exchanger connection is by an inner G½ thread. Following connection to the heating system, bleed and carry out a pressure test.
When concreting, the trench heater must be levelled using the set screws provided and fastened to the floor using the anchors provided. The anchors keep the trench heater in place while pouring concrete.
Using anchors will extend the bottom width of the trench heater by 42 mm from each side.
While pouring concrete, the trench heater may be weighed down.
While pouring concrete it is particularly important to brace the trench heater to prevent longitudinal buckling. Trench heaters are fitted with spacers for this purpose. (Please note: FKP models as standard are, however, not equipped with spacers.) Following concreting, these spacers are easily removed.
While pouring concrete or anhydrite it is essential to seal all connection openings to prevent leakage.
Where the trench heater is not concreted in, floor supports are recommended to be used to incorporate the trench heater into a raised floor. Standard trench heater models are not self-supporting.
We recommend insulating the outer side of the trench heater casing along the length of the heat exchanger with polystyrene to prevent heat loss into the floor.
To avoid contaminating the trench heater, we recommend maintaining the protective hardboard cover in place during construction work. The board, which is included in the standard contents, is not suitable for walking on and serves solely to protect the trench heater from contamination during installation. Strengthened OSB covers for installation purposes are available as option extras.
Trench heaters fitted with stainless steel casings installed in humid environments – marked KORALEX Pool FKP – are equipped as standard with overflow drains. During installation, the pipe at the bottom of the trench heater must be connected to piping with sufficient gradient to drain overflow water. We recommend installing a U-bend to prevent odour.

Recommended positioning of heat exchangers in trench heaters

• Trench heaters should be positioned a maximum of 100 mm from windows. In order to achieve maximum performance, the recommended position for heat exchangers in the trench heater is always on the window side. This results in natural air flow, whereby warm air rises and cool air is drawn into the trench heater. In this way, cool air at the window is screened and the air in the room is heated.

TRENCH HEATER INSTALLATION

1 - trench heater with natural convection, 2 - heat exchanger, 3 - grille, 4 - U-frame, 5 - F-frame, 6 - set screws, 7 - anchors, 8 - up to 300mm deep dividing partition, 9 - window, 10 - floor level, 11 - grout,
12 - expansion joint, 13 - insulation, 14 - concrete filler, 15 - sub-floor

Raised floor installations

• Structural supports for raised floor trench heater installations offer stable and effective solutions. Structural supports are manufactured from non-lacquered steel and are suitable for raised floors of a depth of up to 500 mm. Structural supports are suitable for Optimal FKO and Basic FKB models.

Supports must be ordered together with trench heaters due to structural alterations to convector casings! Components of several types of raised floor support are integral parts of the trench heater body.

Raised floor installations KORAFLEX FK

Trench heater multiple installations

Casing types according to water connections and lowered sides for multiple installations

• Lowered trench heater casing sides are used where invisible connections are desired between trench heaters (multiple trench heaters around a room, eg. in administrative buildings, restaurants, hotels, etc.). When ordering grilles, care must be taken to include information in the order code that the grilles required are to be used with trench heaters with lowered faces.

ORDERING CODES

Example of ordering code: FKB-100/11/26-V1U1P0

KORAFLEX trench heater with natural convection, Basic model, length 100 cm, depth 11 cm, width 26 cm, counter-flow non-lacquered heat exchanger, U-frame, silver elox, right-hand connection to heating system, without lowered face.

KORAFLEX	Convection	Basic		Length/Depth/Width (cm)		Heat exchanger type	Heat exchanger colour	Frame	Frame colour	Connection side	Lowered face
F	K	O	-	100/11/26	-	V	1	U	1	P	0
						V counter-flow P* single-stream 0 without heat exchanger	1 non-lacquered 0 without heat exchanger	U -frame F -frame C for Cross grille 0 without frame	1 silver elox 2 dark bronze elox 3 light bronze elox 5 black elox 9 other RAL colour 0 without frame	right	0 without lowered face 1 lower face – input side 2 lower face – opposite input side 3 both sides lower

P* – single-stream heat exchangers are fitted as standard in trench heaters 140 mm wide, depth of 70, 90 and 110 mm only.

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