Komfovent Duct Heat Exchangers

Installation and Maintenance Manual

Nomenclature

The nomenclature for Komfovent heat exchangers follows a specific structure:

Key of heat exchanger name:
DCF: Duct freon cooler with rectangular connections
DCW: Duct water cooler with rectangular connections
DH: Duct water heater with round connections
DHCW: Duct water cooler with round connections
SVK: Duct water heater with rectangular connections

Additional codes indicate:

Nominal air flow (m³/h) / 1000
Cooling capacity at nominal parameters (kW)
Connection diameter (Ø, mm)
Flange dimensions
Piping row count

Technical Information

Duct heat exchangers are designed for heating or cooling cleaned air in ventilation systems. They are mounted outside the main unit. The coils are typically made of copper tubes and aluminum plates, with housings made of galvanized steel (as shown in Figure 1a).

Figure 1a: Illustration showing the housing of heat exchangers made of galvanized steel.

Coolers with rectangular connections are housed in shield sections (Figure 1b). These sections have a shield thickness of 45 mm and are insulated with mineral stone wool (thermal conductivity λ = 0.037 W/mK). The casing is available in RAL 7035. Cooler sections are equipped with a drop separator and a drain tray (drain tray pipe Ø32 mm). Connecting flanges are L20. Control of heat exchangers is managed by automatic control systems.

Figure 1b: Illustration showing coolers with rectangular connections mounted in shield sections.

Figure 2: Diagram illustrating the dimensions (L, B, H, B1, H1) of an air cooler/heater section with rectangular connections.

Figure 3: Diagrams showing heat exchangers with round connections: (a) heater, (b) cooler, with dimensions (ØD, L, B, H, B1, H1).

Water heat exchangers with round connections are shown in Figure 3. Coolers are supplied with a drain tray (drain tray pipe Ø15 mm).

Key Technical Specifications:

Maximum allowable fluid pressure for water heat exchangers: 21 bar.
Minimum / maximum fluid temperature for water heat exchangers: -21°C / 130°C.
The temperature difference between incoming fluid and outgoing air must be at least 3°C.
Maximum allowable fluid pressure for freon heat exchangers: 42 bar.
Minimum / maximum fluid temperature for freon heat exchangers: -20°C / 80°C.
Maximum recommended air flow velocity through heat exchanger: 3 m/s.

Attention: Earthing must be installed according to EN61557 BS 7671!

Note: It is a must to mount the drainage siphon.

Technical Data Tables

The following tables provide detailed technical data for various heat exchanger models, including capacity, pressure drops, dimensions, and weights.

Table 1. Water and evaporative coolers with rectangular connections

Type	Supply air volume, m³/h	Air temp. in/out, °C	Internal fluid	Capacity, kW	Air pressure drop*, Pa	Hydraulic pressure drop, kPa	B×H×L, mm	Pipe connection	Internal volume, dm³	B1×H1, mm	Weight, kg
DCF-0,4-3	400		R410A	2,8	16	0,4	600×550×390	1/2"/22 mm	0,9	300×400	40
DCW-0,4-3	400		Water 7/12	2,6	30	30,7	505×550×390	1/2"	1,6	300×400	33
DCF-0,5-3	500		R410A	3,5	19	0,6	600×550×390	1/2"/22 mm	0,9	400×300	40
DCW-0,5-3	500		Water 7/12	3,3	30	52,8	600×550×390	1/2"	1,9	400×300	35
DCF-0,7-5	700		R410A	4,8	22	0,6	705×610×390	1/2"/22 mm	1,8	500×400	49
DCW-0,7-5	700		Water 7/12	4,2	22	6,9	705×610×390	1/2"	2,6	500×400	42
DCF-0,9-6	900		R410A	6,2	29	0,9	705×610×390	1/2"/22 mm	1,8	500×400	49
DCW-0,9-6	900		Water 7/12	5,5	30	7,9	705×610×390	3/4"	2,8	500×400	45
DCF-1,2-8	1200		R410A	8,3	43	1,5	705×610×390	1/2"/22 mm	1,8	500×400	49
DCW-1,2-8	1200		Water 7/12	7,4	46	12,8	705×610×390	3/4"	2,8	500×400	45
DCF-1,4-10	1400		R410A	9,7	74	11,8	705×610×390	1/2"/22 mm	2,3	500×400	51
DCW-1,4-9	1400		Water 7/12	8,7	61	16,7	705×610×390	3/4"	2,8	500×400	45
DCF-1,6-11	1600	30/18	R410A	11,1	78	16,4	755×610×420	1/2"/22 mm	2,5	500×400	56
DCW-1,6-11	1600	30/18	Water 7/12	10	65	22,2	755×610×420	3/4"	3,0	500×400	46
DCF-2,0-14	2000		R410A	13,8	71	30,7	920×610×420	5/8"/22 mm	3,1	700×400	65
DCW-2,0-13	2000		Water 7/12	12,8	60	38	920×610×420	3/4"	3,6	700×400	57
DCF-2,5-17	2500		R410A	16,9	67	14,9	1080×670×420	5/8"/22 mm	7,5	800×400	79
DCW-2,5-17	2500		Water 7/12	15,5	63	16,6	1080×670×420	1"	8,4	800×400	65
DCF-3,0-20	3000		R410A	20,8	92	22,1	1080×670×420	5/8"/22 mm	7,6	800×400	79
DCW-3,0-20	3000		Water 7/12	18,7	102	23	1080×670×420	1"	8,4	800×400	69
DCF-4,0-27	4000		R410A	26,9	94	45,6	1220×730×420	5/8"/22 mm	9,8	900×500	97
DCW-4,0-27	4000		Water 7/12	25,2	106	38,4	1220×730×420	1"	10,7	900×500	82
DCF-4,5-31	4500		R410A	30,3	95	35,5	1220×790×420	3/4"/22 mm	10,9	900×600	103
DCW-4,5-30	4500		Water 7/12	28,8	108	62	1220×790×420	1"	11,9	900×600	87
DCF-7,0-48-2	7000		R410A	2×24,2	102	10,2	1500×790×480	2×3/4"/2×22mm	7,7	1200×600	125
DCW-7,0-47	7000		Water 7/12	44,5	100	35,5	1500×790×420	1 1/2"	10,4	1200×600	105
* with droplet eliminator

Table 2. Evaporative coolers with rectangular connections adapted to external condensers MOU

Type	Supply air volume, m³/h	Air temper. in/out, °C	Internal fluid	Capacity, kW	Air pressure drop*, Pa	Hydraulic pressure drop, kPa	B×H×L, mm	Pipe connection	Internal volume, dm³	B1×H1, mm	Weight, kg
DCF-0,4-3	400	30/18,5		2,6	16	0,4	600×550×390	1/2"/22 mm	0,9	300×400	40
DCF-0,5-3	500	30/18,7		3,2	20	0,5	600×550×390	1/2"/22 mm	0,9	400×300	40
DCF-0,7-5	700	30/16,8		5,3	22	0,7	705×610×390	1/2"/22 mm	1,8	500×400	49
DCF-0,9-6	900	30/16,0		7,4	30	1,2	705×610×390	1/2" /22 mm	1,8	500×400	49
DCF-1,2-8	1200	30/17,2		8,9	45	1,7	705×610×390	1/2"/22 mm	1,8	500×400	49
DCF-1,4-10	1400	30/16,8		10,7	74	14,3	705×610×390	1/2"/22 mm	2,3	500×400	51
DCF-1,6-11	1600	30/18,4	R410A	10,7	79	15,3	755×610×420	1/2"/22 mm	2,5	500×400	56
DCF-2,0-14	2000	30/17,7		14,2	71	32,3	920×610×420	5/8"/22 mm	3,1	700×400	65
DCF-2,5-17	2500	30/18,7		15,8	67	13,2	1080×670×420	5/8"/22 mm	7,5	800×400	79
DCF-3,0-20-2	3000	30/17,7		2×10,6	79	12,6	1080×670×420	2×12½"/2×22mm	4,5	800×400	79
DCF-4,0-27-2	4000	30/17,7		2×14,2	80	24,6	1220×730×420	2×5/8"/2×22mm	5,7	900×500	92
DCF-4,5-31-2	4500	30/17,6		2×16,1	82	39,1	1220×790×420	2×5/8"/2×22mm	6,3	900×600	98
DCF-7,0-48-3	7000	30/17,9		3×16,2	100	13,2	1500×790×480	3×5/8" /3×22mm	8,0	1200×600	131
* with droplet eliminator

Table 3. Duct water heat exchangers with round connections

Type	Supply air volume, m³/h	Air temper. in/out, °C	Fluid	Capacity, kW	Air pressure drop, Pa	Hydraulic pressure drop, kPa	B×H×L, mm	Pipe connection	Internal volume, dm³	ØD, mm	Weight, kg
DH-125	450	10/22	Water 60/40	1,8	44	2,2	335×295×152		0,9	125	6,15
DHCW-125	450	26/18	Water 7/12	1,4	69	11,6	335×335×164		1,2	125	11,13
DH-160	450	10/22	Water 60/40	1,8	44	2,2	335×295×152		0,9	160	6,15
DHCW-160	450	26/18	Water 7/12	1,4	69	11,6	335×335×164		1,2	160	11,13
DH-200	900	10/22	Water 60/40	3,6	101	4,5	360×320×152		1,1	200	7,04
DHCW-200	900	26/18	Water 7/12	3,0	153	50,1	365×365×164		1,5	200	12,40
DH-250	900	10/22	Water 60/40	3,6	49	5,4	420×380×152	1/2"	1,5	250	9,30
DHCW-250	900	26/18	Water 7/12	3,1	77	67,6	425×425×164		2,0	250	15,37
DH-315	1600	10/22	Water 60/40	6,5	58	17,9	470×510×152		2,1	315	11,75
DHCW-315	1600	26/18	Water 7/12	5,2	90	13,4	560×515×164		3,0	315	21,60
DH-315M	2000	10/22	Water 60/40	8,1	98	3,6	480×520×132		2,4	315	14,39
DHCW-315	2000	26/18	Water 7/12	6,5	133	20,1	560×515×164		3,0	315	21,60
DH-355	2000	10/22	Water 60/40	8,1	61	28,3	600×510×152		2,4	355	13,34
DHCW-355	2000	26/18	Water 7/12	6,6	55	21,6	605×605×164		2,4	355	25,43

Table 4. Duct water heat exchangers with rectangular connections

Type	Supply air volume, m³/h	Air temp. in/out, °C	Capacity*, kW	Air pressure drop, Pa	Hydraulic pressure drop, Pa	B×H×L, mm	Pipe connection	Internal volume, dm³	B1×H1, mm	Weight, kg
SVK-400×200-2	850	0/22	6,3	37	31	480×320×100	1/2"	0,8	400×200	5,0
SVK-400×200-4	850	-23/22	12,8	69	33	517×320×130	1/2"	1,3	400×200	7,0
SVK-500×250-2	1500	0/22	11,1	70	14	617×320×100	1/2"	0,9	500×250	6,0
SVK-500×250-4	1500	-23/22	22,6	131	17	617×320×130	1/2"	1,5	500×250	9,0
SVK-500×300-2	1800	0/22	13,3	65	24	617×380×100	1/2"	1,1	500×300	7,0
SVK-500×300-4	1800	-23/22	27,2	122	26	623×380×130	3/4"	2,1	500×300	12,0
SVK-600×300-2	2300	0/22	17	73	40	717×380×100	1/2"	1,2	600×300	8,0
SVK-600×300-4	2300	-23/22	34,7	137	25	723×380×130	3/4"	2,3	600×300	13,0
SVK-600×350-2	2600	0/22	19,2	65	21	717×440×100	1/2"	1,5	600×350	9,0
SVK-600×350-4	2600	-23/22	39,2	123	25	723×440×130	3/4"	2,8	600×350	15,0
SVK-700×400-2	4000	0/22	29,6	120	52	817×500×100	1/2"	3,1	700×400	12,0
SVK-700×400-4	4000	-23/22	60,3	226	53	830×500×130	1"	6,4	700×400	18,0
SVK-800×500-2	4500	0/22	33,3	92	14	923×560×100	3/4"	4,1	800×500	14,0
SVK-800×500-4	4500	-23/22	67,9	172	14,2	937×560×130	1 1/4"	8,5	800×500	21,0
SVK-1000×500-2	5700	0/22	42,1	94	22	1123×560×100	3/4"	4,9	1000×500	16,0
SVK-1000×500-4	5700	-23/22	86	177	23	1137×560×130	1 1/4"	10,1	1000×500	25,0
* Internal fluid temperature 80/60 °C.

The technical data presented in tables 1-4 cover capacity, air pressure drop, hydraulic pressure drop at different air flows, and parameters like cooling capacities (calculated at 50% relative humidity). Weights, dimensions, and connection specifications are also provided.

Installation of Heat Exchangers

The unit is intended for indoor use only, within a temperature range of +5°C to +40°C. Coolers must be installed such that the air flow direction is horizontal. For heat exchangers, the water flow direction must always be opposite to the air flow direction.

Figure 4a: Diagram showing fluid flow direction in respect of air flow in coolers with rectangular connections. 'A' indicates water/refrigerant out, 'B' indicates water/refrigerant in.

DH and DHCW heat exchangers are equipped with a return water temperature sensor, mounted according to the fluid flow direction (Figure 4b).

Figure 4b: Diagram showing fluid flow direction in respect of air flow in heat exchangers with round connections. 'A' indicates water out, 'B' indicates water in, 'T' indicates temperature sensor.

Before installation, heat exchangers should be thoroughly flushed with water. DCF heat exchangers are filled with nitrogen gas, which must be released through a valve.

Attention! When screwing fitting pipes onto the system, hold them with a tube wrench, as shown in Figure 5a.

Figure 5a: Illustration depicting a correct heat exchanger fitting pipe connection, emphasizing the use of a tube wrench for proper installation and maintenance access.

Figure 5b: Illustration showing the installation of a return water sensor.

Attention! Fig. 5a shows correct heat exchanger fitting pipe connection. Wherever possible, heat exchanger pipes should be connected in such a way as to ensure free access to pipe work for maintenance. When carrying out installation of heat exchanger pipes, make sure that liquid (evaporative refrigerant) supply is completely disconnected.

The sensor shown in Figure 5b must be thermally insulated and connected to the controller terminals (refer to the automatic control manual for details).

Before starting up the air handling unit, working evaporative refrigerant should be injected into the heat exchangers. The heat exchanger can be filled with water and 30% ethylene glycol liquid.

Consult the technical documentation of the ethylene glycol liquid supplier for specific handling instructions. Never pour glycol down a drain; collect it in a receptacle and take it to a recycling center. Glycol is hazardous if consumed and can cause poisoning or kidney damage. Seek medical attention if ingested. Avoid breathing glycol vapor in confined spaces. If glycol gets into the eyes, flush thoroughly with water for approximately 5 minutes.

Cleaning and Inspection of Heat Exchangers

The plates of heat exchangers and droplet eliminators should be cleaned regularly to ensure efficient heat exchange between the coil surface and the air flow. Cleaning frequency should be determined by air purity and the use of in-line filters.

Always clean the heat exchanger against the regular direction of airflow. Ensure the coils are purged of air. If a droplet eliminator is fitted, remove it and clean it with water. Also, check that the condensate drain is not clogged.

Water Trap Installation

The bend of the water trap can be repositioned to the right or left. The drain line from the water trap must be routed to avoid damaging adjacent unit sections or building elements. If the drain line passes through cold spaces, it should be insulated to prevent freezing, and a heating cable may be required.

Water trap installation for a unit section mounted on the suction side

Since fans in most air handling units are positioned at the end of the functional chain and generate sub-atmospheric pressure inside the unit, correct installation of the water trap is crucial. This prevents condensate from being poorly eliminated, which could lead to condensate accumulation. Height H₁ must be at least equivalent in mm to half of the negative pressure inside the unit (measured in mm water gauge). Height H₂ must be at least equivalent in mm to the negative pressure inside the unit (measured in mm water gauge).

Figure 6: Schematic diagram illustrating the principle of correct drainage siphon installation, showing condensate flow and height requirements (H1, H2).

Precaution: The drainage siphon should be mounted on the outlet fitting pipe of every drip tray for complete condensate drainage from the air handling unit and to prevent the penetration of offensive odors from an effluent into the ventilation system.

Water trap installation for a unit section mounted on the pressure side

When fans are not at the end of the chain and generate over-atmospheric pressure inside the cooling section, condensate can be easily removed from the AHU. In such cases, there are no strict requirements for siphon installation; a drainage siphon with a minimum rake is sufficient.

RECOMMENDATION: The drainage siphon must be installed with a pipe diameter of not less than the specified size.

Service and Support

LITHUANIA: UAB KOMFOVENT, Phone: +370 5 200 8000, service@komfovent.com, www.komfovent.com

FINLAND: Komfovent Oy, Muuntotie 1 C1, FI-01510 Vantaa, Finland, Phone: +358 20 730 6190, toimisto@komfovent.com, www.komfovent.com

GERMANY: Komfovent GmbH, Konrad-Zuse-Str. 2a, 42551 Velbert, Deutschland, Phone: +49 0 2051 6051180, info@komfovent.de, www.komfovent.de

LATVIA: SIA Komfovent, Bukaisu iela 1, LV-1004 Riga, Latvia, Phone: +371 24 66 4433, info.lv@komfovent.com, www.komfovent.com

SWEDEN: Komfovent AB, Älggärdesvägen 12A, 433 30 Partille, Sverige, Phone: +46 31 487 752, info_se@komfovent.com, www.komfovent.se

UNITED KINGDOM: Komfovent Ltd, Unit C1 The Waterfront, Newburn Riverside, Newcastle upon Tyne NE15 8NZ, UK, Phone: +447983 299 165, steve.mulholland@komfovent.com, www.komfovent.com

Partners:

AT: J. PICHLER Gesellschaft m. b. H. www.pichlerluft.at

BE: Ventilair group, ACB Airconditioning, www.ventilairgroup.com, www.acbairco.be

CZ: REKUVENT s.r.o., www.rekuvent.cz

CH: WESCO AG, SUDCLIMATAIR SA, CLIMAIR GmbH, www.wesco.ch, www.sudclimatair.ch, www.climair.ch

DK: Øland A/S, www.oeland.dk

EE: BVT Partners, www.bvtpartners.ee

FR: ATIB, www.atib.fr

HR: Microclima, www.microclima.hr

HU: AIRVENT Lågtechnikai Zrt., Gevent Magyarország Kft., Merkapt, www.airvent.hu, www.gevent.hu, www.merkapt.hu

IE: Lindab, www.lindab.ie

IR: Fantech Ventilation Ltd, www.fantech.ie

IS: Blikk & Tækniþjónustan ehf, Hitataekni ehf, www.bogt.is, www.hitataekni.is

IT: ICARIA, www.icaria.srl

NL: Ventilair group, DECIPOL-Vortvent, CLIMA DIRECT BV, www.ventilairgroup.com, www.vortvent.nl, www.climadirect.com

NO: Ventilution AS, Ventistål AS, Thermo Control AS, www.ventilution.no, www.ventistal.no, www.thermocontrol.no

PL: Ventia Sp. z o.o., www.ventia.pl

SE: Nordisk Ventilator AB, www.nordiskventilator.se

SI: Agregat d.o.o, www.agregat.si

SK: TZB produkt, s.r.o., www.tzbprodukt.sk

UA: TD VECON LLC, www.vecon.ua

For more information, visit: www.komfovent.com

This symbol indicates that this product is not to be disposed of with your household waste, according to the WEEE Directive (2002/96/EC) and your national law. This product should be handed over to a designated collection point, or to an authorised collection site for recycling waste electrical and electronic equipment (EEE). Improper handling of this type of waste could have a possible negative impact on the environment and human health due to potentially hazardous substances that are generally associated with EEE. At the same time, your cooperation in the correct disposal of this product will contribute to the effective usage of natural resources. For more information about where you can drop off your waste equipment for recycling, please contact your local city office, waste authority, approved WEEE scheme or your household waste disposal service.

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