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  Refurbishment Kits: Non-typical Solutions

Induction Ratio - Increases efficiency of existing Induction Units, typically 30% to 75%
Cooling / heating duty - Increases cooling/heating capacity, typically 5% to 12%
Noise - Reduces jet noise emanated by existing Induction Units, typically 7 dB(A) to 15 dB(A)
Primary air pressure - Reduces primary air pressure, typically 150 Pa (0.6") to 200 Pa (0.79")
Energy consumption - Reduces energy consumption typically 30% to 40%
Increased nett lettable area - Increases Lettable floor space, typically 8% to 15%

Induction Ratio
DADANCO's revolutionary STARLINE nozzle, with it's unique properties, enables entrainment of surrounding air into the jet at a much greater rate than conventional nozzles do.

Conventional

Dadanco

Potential "core" zone of the DADANCO nozzle, with it's enlarged surface area enables more air to be entrained into the jet in the immediate vicinity of the outlet of the nozzle.

Conventional Dadanco


Cooling / heating duty
As DADANCO nozzles increase induction (entrainment) ratio of an induction unit, secondary air drawn through a secondary heat exchanger (coil) is increased for the same quantity of primary air being discharged through primary air nozzles.

Cooling/heating duty of a heat exchanger is proportional approximately to the 1/2 power of the velocity increase (secondary air flow rate increase) for all other parameters being equal.

Please refer to a table below for expected increase in cooling capacity of your refurbished induction unit (the values below depend on cleanliness of heat exchangers, thermodynamic parameters, etc):


Entrainment Ratio

5%

10%

15%

20%

25%

30%

35%

40%

Capacity

2%

4%

6%

8%

10%

12%

14%

16%

  Total cooling (heating) capacity is a sum of primary air cooling (heating) capacity and secondary air cooling (heating) capacity:
Qtot = Qpa + Qsa

 
Noise
CFD Modeling shown below shows that length of the jets are substantially different. In the case of conventional nozzle (left) jet is much longer than in the case of DADANCO nozzle.

Conventional

Dadanco
It is well known that the sound power level of the jets is proportional to the 8th power of the velocity as well as to the length of the potential core zone.

By reducing the length of the core zone, the source of the noise is being reduced and also the velocity of the jet.

When comparing the noise emanated from old induction units (Carrier, Trane, Worthington…), for the same primary air flow and pressure, DADANCO nozzles achieve dramatic noise reduction - of the order of 5dB(A) to 16 dB(A).

All tests are performed at NATA certified laboratories at The University of Adelaide, South Australia.

Get a noise test report
, prepared by the University of Adelaide

Primary air pressure
Due to increased entrainment ratio with DADANCO new technology nozzles, primary air pressure can be reduced down to 150 Pa (0.6") to 250 Pa (0.79") without any performance penalty.

For the same cooling/heating capacity required, primary air pressure can be reduced. This is due to increased secondary airflow through a secondary heat exchanger that in turn increases its cooling duty. In order to maintain the same cooling/heating duty, primary air pressure can be reduced which in turn reduces primary air flow.

Increase in entrainment ratio and corresponding increase in cooling/heating duty of a secondary heat exchanger would cater for reduction of primary air capacity.Collateral benefit of reduced pressure is reduction of energy consumption of primary a air fan and further reduction of noise (sound power level) emanated from the units.


Energy consumption
Energy consumption of a primary air fan is a major "consumer" of energy in a building. Energy consumption is directly proportional to the air flow as well as to a pressure head.

P = (Q x Dp)/h


Reduction of either Primary Air quantity (Q) or Pressure Head (Dp) that is now achievable with the novel DADANCO technology, results in proportional reduction of energy consumption of a subject fan.
Increased nett lettable area
Throughout the 50's, 60's and early 70's, considerable proportion of floor mounted (under sill, wall mounted, etc…) induction units have been installed around the World.

Those induction units occupy the most valuable area of any property - perimeter wall area - until now.

DADANCO STARLINE CM induction units have been used widely to replace Floor Mounted units of various brands.