Greenway

  As ever on a budget waste not want not approach. mostly stuff I had in stock Code ERV Code Six individually fused channels Power board shown in place. 35 Amp Hall effect current sensor. Driver code here  ERV Code Dashboard for ERV fan control and testing      Six controlled channels with 25Khz PWM fan speed control The first layer of the system. Two Arduinos one for control one for networking, Code here  ERV Code

  New dual rotor fans slower and quieter, lower power with better static pressure. Testing shows these to be as good in terms of flow as the faster fans but with more static pressure. I suppose they are designed for use in ducting in a car.  ERV Sensors looking good revised location to get them, deeper into the airflows. All looks good, there is a throttle valve on the bypass now with a single servo. After testing the 4 port valve is not good enough it seems, no surprise. I'm looking at a simple bypass mode with a mixed fresh and conditioned inlet stream.

A bit or research and it seems a plenum on the outlet of the heat exchanger seemed worth a try. 60 Litre Plenum on the vent side. Seems to make the vents more balanced measuring the flow I can regulate the rate more evenly with one vent having less effect on the others, I'm going to add a presure sensor to the chamber see if there is any pressure in it I noticed coupling between room vents. e.g. I set one room and move to the next then recheck the first vent and its flow rate was changed. I was never happy with all those Y junctions, a very poor manifold design I suspect. As an added bonus its made the vent even quieter too. It works well within a range I can set the vent flows independently of one another, also the living room and office flows are much improved which have the longest ducts. The flow at the office and living room are 50% higher if needed now which is great for working at home. The office got warm and sticky in the past, not anymore. More Photos Sound test My refere...

 We get around a 1C boost to the fresh air from loft heat exchange with the duct. The loft is consistently between 4 and 15 C hotter than the outside air and even at night boosts heat in the fresh air duct to the living room. An unanticipated benifit

The ERV core, source selector valve and exhaust damper valve The Duct We will re-use the vent in the bathroom ad add an additional exhaust vent in the living room. This gives us two air circuits that can be independently controlled, for when the living room door is shut. Furry User Case The cat is in the living room overnight with the door closed and may use the litter so we would want some air exchange in this room while sleeping and keeping the bedrooms fresh.

  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.

  After a few experiments I decided I wanted the following options for the input air source. 1) Fresh air from roof top. Function as a vanilla balanced ERV ventilation system, all exhaust air passes through the heat exchanger, all incoming air is warmed by the heat exchanger. 2) Loft air, typically warmer if the Sun is out even on a cold day. Reduce need for heating during the day. 3) Fresh Air bypassing the heat exchanger to reduce the need fore running the heat pump on sunny days when the air temperature is still quite low. 4) Block all four ports to prevent air moving from convection or an open window raising or reducing air pressure in the room. So the four port valve was born. ts got a dual drive now which works really well. The wooden gear was inspired by the Marble Machine i have toughened the teeth with Epoxy now which make it quite substantial.