1. MBB box
When performance matters….
Secure, Flexible and Simple

2. Background...
An independent Swedish report shows generally low accuracy on flow-measurement of plenum boxes in the ventilation market
Quotes from the report:
“For ceiling diffusers with plenum box we have found that the distance to disturbing source often has larger impact for calculation of air flow than the suppliers indicates. Even the position of the damper often has influence but that is not mentioned in the suppliers instructions for calculations of air flow... We request that suppliers correct the majority of K-values and improve the documentation and labelling”.
“If a diffuser has more K-values it provides substantially better opportunities to get correct measuring results”.
This we had to take seriously

3. Background... Why plenum box? The box shall be;
Balance ventilation system
Measure air flow
Reduce noise
Even distribution to diffusers
The box shall be;
Quiet
Accurate
Small
Simple
Readable

4. Balancing principles... 1. Rotating 2. Sliding 3. Linear
Must be perforated for noise
“Only fine-tuning”
2. Sliding
3. Linear
4. Linear cone
“0”-100 % air flow
Linear characteristics
Low noise
Dotted Line = old MBA

5. Measuring principles 1. Before the damper 2. Over the damper
Sensitive to bends or installation
Poor in low flow range
2. Over the damper
Variable k-value
3. After the damper
More pressure drop
Variable k-value for high accuracy
4. Over the diffuser
Not for high flow rate diffusers
Different k-values for diffusers

6. Air distribution principles...
1. Damper cone
Needs a certain width
No extra equipment
2. Closed perforated plate
More pressure drop
3. Open perforated plate.

7. Secure... High capacity and low sound even at high pressure
CFD-, and laboratory tested
Completely unique damper solution
Smaller box
Usable in systems with chilled beams.

8. Secure... High capacity and low sound even at high pressure =
Capacity of NS19+MBB
Example: Competitor 1 and 2 can manage about 45l/s on a 125mm connection.
Lindab about 58 l/s.
Competitor 1
Competitor 2 =
Preconditions: 100Pa and sound power level 34dB(A)
(Enquiry from main customer)

9. Secure... Money saving A traditional system of 40 diffusers
Dampers and silencers
38 dB(A)
Total cost SEK
Exchange MBA with MBB
32 dB(A)
Similar cost OK
Cost material:
Box MBA-125/160, 40 pcs.
Damper, DRU 315, 4 pcs.
Silencers, LRCA , 4 pcs.
Damper DRU 125, 4 x 5 pcs.
Silencer SLCU , 4 x 5 pcs. = 20 pcs.
Connection ducts dim 125, length 3 m, 40 pcs.
Total: 42,100 SEK (netto)
Cost mounting:
Total: 52 hours, approx. 18,000 SEK

10. Secure... Money saving Remove Silencers Remove Dampers 34 dB(A)
Total Cost SEK
Go down one size
+ 7 pa – approx. 1,6 % higher energy consumption
Still below 38 dB(A)
Total Cost SEK
Savings of appr. 37%.
Cost material:
Box MBB-100/160, 40 pcs.
Connection ducts dim 100, length 3 m, 40 pcs.
Total: 24,500 SEK (netto)
Cost mounting:
Total: 38 hours, approx. 13,300 SEK

11. Flexible... 0-100% operational area
Possible to have low flow with high pressure
20 l/s, 100 Pa LWA= 24 dB(A)
And high flow with low noise
76 l/s, 70 Pa LWA=34 dB(A)
With 125mm connection!!!!

12. Flexible... Viable for future applications
The MBB box can cope with almost any future demands
Always possible to balance it to a lower flow
Together with e.g. LKP/LCP you make sure to have unique operating range all the way down to zero also concerning air movements
Very high damping without generating a noise problem

13. Simple... Simplifying balancing Damper with readable k-values
Easy to reach and read the scale
K-values fixed to damper positions
K-values are independent of diffusers
Can be pre- and re-balanced (CADvent)
Steady high measuring pressure even at low flow
Better adjustment characteristics (No “Ketchup effect”)
100%
50%

14. Simple... Small dimensions Easy handling, mounting and cleaning
Smaller ducts because of larger capacity
Lower Carbon footprint (Less material, less transports, less packaging material)
Easy installing with Safe / Safe Click connection
Low building height
Insulation prevents sound generating from outlet (Inlet diffuser increases sound otherwise)
Dimension
Lindab
Comp. 1
Comp. 2
100/125
Height
160 mm
180 mm
220 mm
240 mm
255 mm
310 mm
340 mm
345 mm

15. MBB box When performance matters... Secure Flexible Simple
Low sound – high pressure
Less dampers and silencers – still silent
Accurate measurement – no problem with disturbing sources before the box
Reliable measurement – variable k-values
Flexible
0-100% dynamic operational area
Low flow with high pressure
High flow with low noise
Viable for future system changes
Simple
Linear damper means easy and quick balancing
Prebalancing is possible
Small dimensions – easy to handle and install
Easy to clean

16. Simplified construction…
lindab | comfort
Simplified construction…