Greenway

  This is a rough break down of materials costs NZ$28 1 X 60 litre Sistema box NZ$30 3 X 7500CPM main fans NZ$20 4 X 6500RPM booster fans NZ$3.50 4 X Fan speed controllers NZ$30 1 X 30 Amp PSU NZ$104 5 X diffusers with 3M of duct and Y junction NZ$21 4 X 150mm 3M ducts NZ$14 2 X 150mm 1M ducts NZ$1.00 12 X 150mm PVC flower pots NZ$15 6 X 6mm Corroplast sheet 900 X 1200 NZ$ 50 Arduinos and breakouts for project NZ$!00 Wire plugs sockets misc electrical NZ$60 New tools NZ$150 Tape screws wood sundry hardware Hot glue sticks NZ$30 2 X Sitema filer boxes NZ$12 2 X Foam exercise mats NZ$30 PC Servos NZ$100 Experiments breakages re-work Total NZ$1,510

 Looking at the specifications of propitiatory systems it seems that the fans are nothing special. They typically use Axial flow fans with AC voltage motors around 60 Watts seems suitable for our house. In order to allow me to do this without an electrical certificate my system is entirely 12 volt.  The fans I have are pretty quiet to so it seems like win win to me less that US$30 each for the 60 W devices and US$16 for the boost fans. Computer fans are a good low cost option. Quiet long lived and they have built in speed controllers too. I am using two fan types in the system. I bought them cheapef than this Specifications : -- Size: approx. 120*120*38 mm -- Voltage: 12(V) -- Blast Capacity: 280.38CFM -- Current: 5.0A -- Rotate Speed: 7500CPM(r/min) -- Noise Level: 64DBA -- Wind Pressure: 24.60 mmH2O -- Bearing: High precision double ball bearing -- Operating Temperature: -10℃ ~ + 70℃ -- Storage Temperature: -40℃~+70℃ -- Power range: Plus or minus 15% of rated power supply -- Insulati