The calculations are based on the following table with measured figures for the pipe dimensions and Silvent’s air nozzles. The cost savings in the table are calculated assuming the cost of compressed air is 1,8 pence (GBP) per Nm3 and the blowing time is 2 hours per day.
| Open pipe | ||
|---|---|---|
| Pipe interval | Noise Level | Air consumption |
| Ø mm | dB(A) | Nm3/h |
| 2 | 84 | 8 |
| 2.5 | 87 | 12 |
| 3 | 90 | 17 |
| 4 | 95 | 30 |
| 5 | 99 | 47 |
| 6 | 102 | 67 |
| 7 | 105 | 92 |
| 8 | 108 | 118 |
| 10 | 112 | 185 |
| 12 | 116 | 266 |
| 14 | 119 | 363 |
| 16 | 122 | 474 |
| 17 | 123 | 536 |
| 18 | 124 | 599 |
| 20 | 126 | 740 |
| 25 | 131 | 1159 |
| 32 | 139 | 2677 |
| Silvent air nozzle | |||
|---|---|---|---|
| Replace with | Noise reduction | Air savings | Annual savings |
| dB(A) % | Nm3/h % | GBP | |
| MJ4 | 8 43% | 4 50% | 37 |
| MJ5 | 8 43% | 2 17% | 19 |
| MJ6 | 8 43% | 3 18% | 28 |
| X01 | 17 69% | 16 53% | 150 |
| 1011 | 15 65% | 21 45% | 197 |
| 9002W | 22 78% | 37 55% | 346 |
| 973 | 19 73% | 34 37% | 318 |
| X03 | 19 73% | 65 55% | 608 |
| 705 L | 19 73% | 90 49% | 842 |
| X07 | 20 75% | 146 55% | 1 367 |
| 710 L | 19 73% | 147 40% | 1 376 |
| 412 L | 34 89% | 270 57% | 2 527 |
| 715 C | 23 80% | 225 42% | 2 106 |
| 715 L | 20 75% | 287 48% | 2 686 |
| 720 | 22 78% | 320 43% | 2 995 |
| 735 L | 22 78% | 391 34% | 3 660 |
| 780 LA | 20 75% | 927 35% | 8 677 |
In the example below, we assume you have a Ø 6 mm open pipe, the compressed air costs 1,8 pence (GBP) per Nm3, and that you have a blowing time of 2 hours per day.

Blowing time per year:
52 weeks x 5 days x X hours/day
52 weeks x 5 days x 2 hours/day = 520 hours/year
Saved Nm3 per year:
Air savings Nm3/h x blowing time
37 Nm3/h x 520 h = 19 240 Nm3/year
Saved GBP per year:
Air savings Nm3/h x compressed air cost x blowing time
37 Nm3/h x 0,018 (GBP) x 520 h = 346 GBP/ year
Sound level reduction dB(A):
Sound level open pipe – sound level air nozzle
102 dB(A) – 80 dB(A) = 22 dB(A) sound level reduction
Please contact one of our representatives if you want help calculating your sound level reduction and energy savings, when replacing an open pipe. Our representatives have extensive experience and expertise in the subject.