Danfoss VMTD-N-B Fact sheet

Fact sheet

Termix VMTD-N-B

District heating substation for direct heating and instantaneous domestic hot water with thermostatic control.

Application

The Termix VMTD - N - B is a complete
solution with built-in water heater and
a differential pressure controlled heat­ing system. Termix VMTD - N - B is appli­cable for single and multi-family houses
and for decentralized systems.

District heating (DH)

The substation is prefabricated with
a differential pressure controller, a fit­ting piece and sensor pockets for inser­tion of a heat meter as well as strainer
and ball valves.

Heating (HE)

The heating circuit is designed for direct
generation of heat. The differential pres­sure control sets the optimum opera­tion conditions for radiator thermostatic
valves in order to enable individual tem­perature control in each room. In order
to enable a time-depending tempera­ture control program, a zone valve with
actuator and a room thermostat can be
included.

Domestic hot water (DHW)

The domestic hot water is prepared in
the heat exchanger and the tempera­ture is regulated with a thermostatic

control valve. The patented sensor
accelerator accelerates the closing of
the Danfoss AVTB valve and protects
the heat exchanger against overheat­ing and lime scale formation. The heat
exchanger cools the DH water very
efficiently, thereby creating a very good
operating economy. The sensor accel­erator and AVTB valve also works as
a bypass keeping the house supply line
warm. This shortens the waiting periods
during summer when the heating sys­tem is in reduced operation. The sensor
accelerator helps to ensure a stable hot
water temperature regardless of varying
loads, flow temperatures and differen­tial pressure without the need for read­justing the valve.

Options

The Termix VMTD - N - B can be supplied
with built-in non-return valve and safety
valve mounted in the cold water supply.
It can also be supplied with a thermo­static circulation valve.

Construction

All pipes are made of stainless steel. The
connections are made by nuts and gas­kets. The Termix VMTD - N - B can be deliv­ered with white-lacquered steel cover in
modern design.

FEATURES AND BENEFITS

• Substation for DH and
decentralized systems

• Direct heating and DHW
temperature regulation with
a thermostatic control valve

• Capacity: 29 – 80 kW for DHW,
15 – 23 kW for HE

• DHW in sufficient quantity

• Operates independently
of differential pressure
and flow temperature

• Minimum space required
for installation

• Pipes and plate heat exchanger
made of stainless steel

• Minimized risk of lime scale
and bacteria formation

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CIRCUIT DIAGRAM

DHW

CWM

CW

DHF

DHR

41a

14

41b

9

Technical parameters:

Nominal pressure: PN 10
DH supply temperature: T
DCW static pressure: p
Brazing material (HEX): Copper

Weight excl. cover: 15 kg

(incl. packing)

= 120 °C

max

= 0,5 bar

min

Cover: White-

lacquered steel
sheet

Dimensions (mm):

Without cover:
H 700 × W 300 × D 200 mm

Water

heater

B

7

31

Connections:

1 DHF District heating flow
2 DHR District heating return
3 HFL Heating flow line
4 HRL Heating return line
5 DCW Domestic cold water
6 DHW Domestic hot water
7 CWM Cold water mains

B Heat exchanger DHW
7 Thermostatic valve
9 Strainer
14 Sensor pocket, energy meter
31 Differential pressure controller
41A Fitting piece, energy meter ¾" × 110 mm
41B Fitting piece, cold water meter ¾” × 80 mm

HFL

HRL

Connections sizes:

DH + HE: G ¾” (int. thread)
DCW + DHW: G ¾” (int. thread)

Options:

• White-lacquered steel cover
(on the wall)

• Safety valve and non-return valve
(10 bar)

• Pressure compensation valve (GTU)

• Room thermostat

• Thermometer

• Ball valves

• Zone valve, on/off function

DHW: CAPACITY EXAMPLES

Substation

type

VMTD-N-B-1

VMTD-N-B-2

VMTD-N-B-3

© Danfoss | DCS-SDGPT/ PL | 2021 . 08

DHW

Capacity

kW

29,3 60 23 10/50 20 10,5
37, 8 70 25 10/50 20 13, 6
34,7 60 24 10/50 20 12, 4
45,1 70 21 10/50 20 16 ,2

60 60 23 10/50 35 21,3
80 70 20 10/50 35 28,8

Supply flow

Primary

°C

Return flow

Primary

°C

DCW / DHW

°C

Pressure loss

Primary

kPa

AM029786470623en-010301

Flow rate

Secondary

l/min