Space saving design

Prefabricated unit

Easy to install

TTM Shuntopac® U 20-50 VÅ

Shunt unit for heat recovery system

Shuntopac® U 20-50 VÅ is a shunt unit for heat recovery systems and is available as standard with connection dimensions from DN 20 up to DN 50. The shunt unit can be equipped with components of any make and with several different connection options.

TTM Shuntopac® U 20-50 VÅ VÅ is supplied with a fire and corrosion proof housing of polyester coated aluminium sheet. Standard insulation is AF/Armaflex AF-4. The suspension system consists of brackets in yellow chromate plated iron.

The standard version pipe package consists of fully-welded pressure vessel pipe SS-EN 10216-2 and DIN 2391, rustproofed with grey primer. Pipe packages in other qualities or with another surface treatment can be supplied to order.

TTM Shuntopac® U 20-50 VÅ is CE-marked in accordance with the manufacturer’s declaration 2B according to the Machinery Directive.

The shunt unit is environmentally approved.


1. Control valve
Seat valve with threaded connection in a choice of make and type. The valve is installed in a flange joint to facilitate servicing and replacement.

2. Thermometers4 pcs, graduated -40 – +40 °C. Installed with silicon thermal transfer paste.

3. Shut-off valves
3 pcs ball valves with full throughflow and extended stem. Installed on pipe package with conical coupling.

4. Adjustment valve
1 pc in a choice of make and dimension for adjustment of total flow. Installed on pipe package with conical coupling. Make: TA STAD supplied as standard. 

5. Pump
Choice of make and type with “wet” or “dry” motor.

6. Adjustment valve
1 pc TA STAD for adjustment of bypass flow.

7. Drainage
Version with hose screw connection R 1/2”.

8. Test sockets
Type TA STAD, installed on all connections.

Special design

  • Pipe mixing loop made of e.g., copper or stainless steel of the desired quality
  • Anti-corrosive painted pipe mixing loop, e.g. epoxy enamelled


  • Floor stand


Total flow
1. Connect differential pressure instrument to adjustment valve with measuring point.
2. Set the control valve to fully open position (stem depressed, bypass closed).
3. Measure the water until it reaches the calculated value.

Bypass flow
4. Set the control valve to fully closed position (stem up, bypass open).
5. Adjust the inner adjustment valve until the outer adjustment valve achieves the same pressure drop as before.

System example

TTM Shuntopac® U 20-50 VÅ differential pressure measurement

All outside valves on the TTM Shuntopac® U 20-50 VÅ are provided with test sockets, allowing complete differential pressure measurement.

B – C Pressure drop in supply air circuit.
H – D Pressure drop in exhaust air circuit.
D – E Head over circulation pump.
C – G Pressure drop over control valve.
F – H Differential pressure measurement over adjustment valve in exhaust air circuit.

Dimensions TTM Shuntopac®  U 20-50 VÅ 

Connection DN2025324050
C285 + pump285 + pump285 + pump285 + pump305 + pump
J800 + pump800 + pump800 + pump800 + pump1050 + pump
LSpace for actuators, assembly and maintenance.Space for actuators, assembly and maintenance.Space for actuators, assembly and maintenance.Space for actuators, assembly and maintenance.Space for actuators, assembly and maintenance.
Weight, approx. kg3237525762

Max. pressure: 1,0 MPa
Temp. range: -20 – +110 °C
Specified dimensions are valid for the standard version. Some variations may occur if alternative equipment is used.

TTM Shuntopac® U 20-50 VÅ

Constant flow in exhaust air heat exchanger circuit.

Variable flow in supply air heat exchanger circuit.

The control valve is installed as a mixing valve.

01 VÅ

02 VÅ


TTM SHUNTOPAC® Green Line is a category of shunt units equipped with low-lead valves. Green Line is intended for customers with high demands for improved environmental assessments


TTM SHUNTOPAC® Dynamic gives correct regulation even in systems with varying differential pressures or where the differential pressure is unknown.


TTM SHUNTOPAC® EM is a category of shunt units equipped with ultrasound energy metering equipment according to EN 1434 class 2 and MID 2004/22/EC.


Simonsland in Borås

When Kanico created a new district in the town of Borås, they chose TTM to supply shunt units for the HVAC systems. The area is called Simonsland and contains 60,000 m2 of buildings.


TTM Energiprodukter was one of the suppliers in the construction of the prestigious Copenhagen Opera House Together with their reseller, the company succeeded in winning the deal and delivering 98 different shunt units.


NCC are building their new head office at Järva Krog in Solna. The new head office has a strategic and easily accessible position adjacent to the E4 motorway.