Greenway

Smart control: - reduces power costs of air handling units - adjusts ventilation to your everyday needs - provides a wide range of control options It has been estimated that smart control allows to half the average cost of electricity for ventilation.

  I wanted to avoid having the Arduino generate the 25 KHz PWM signal for the fan seed control pilot signal. Here ia a cheap as chip's wee board that I have modified to allow the Arduino to send an analogue voltage as fan speed demand. The modification is simply lifting the leg of the two trimmer pots for fans 2 and 3 and connecting that leg to the Arduino output.

  This is a 2 port flap valve allowing proportional control of the exhaust stale air extraction side of the system. We have chose two exhaust locations Bathroom and a new vent in the living room. This design allows us to have two climate zones one for the living room and one for the bedrooms and the rest of the house. Its designated Turbo because it has 60 Watt fan embedded in it to boost the air flow to help match the input flow from the inlet and booster fans.

 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 --...