Greenway

 Speed Control added to ERV heat exchanger fans and a recirculation/bypass valve between the inlet and exhaust fan. Flower pots hot glue and tie wraps the corner stone of any ventilation system.  Its a throttle valve in a manifold between the inlet and exhaust fan plenums. Fan speed is set using the existing Wemos D1 R2 which can output 25Khz accurately to drive the PWM fan speed demand signal. Code changes to the ERV DAS and the ERV Controller and related Hubitat drivers, now renamed,  Ventilation Controller as it manages the boost fans for the zones. Drivers Some testing with no pipes connected showing the blockage effect of the heat exchanger core Exhaust fan only recirculate open 100%

  Simple loft fan rule

 

 

More DAS Data ERV Temperature vs Rooms and Outside HVAC Activity and Cost NZ$ Bedroom Temperatures 1-11-2020 Bedroom Humidity 1-1-2020

  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. Air Quality Hubiat Prototype 1 of control system

 Matt Resinger on youtube has a lot of videos about the subject. He’s a custom home builder, so he does favor the more expensive materials. But he’s also very focused on making sure things last a long time. I find a lot of his stuff interesting. Here’s one where Matt talks ERV vs HRV Here are a couple This Old House videos on the ERV subject: Seeing it work with smoke bombs A discussion on indoor air quality

Encouraging results  from logged data. Very stable internal environment in the house.  Energy use for Greenway Room temperatures All rooms are very similar so the heat is being distributed evenly it seems.  Room humidity Very important as we are still having col mornings the humidity is also very well distributed.  

I do want to increase the maximum flow rate for the inlet so an additional fan in the inlet filter should help overcome the blockage in the filter its self and heat exchanger core. New filter fan to be placed in the inlet duct. Its in a Sistema box that fits the following filter almost perfectly Features: Double-layer activated carbon filter cloth High filtration efficiency High dust holding capacity Good temperature Resistance Economical, practical and easy to install   There is an additional mesh filter to catch larger debris like leaves  Airflow Sound level

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

  Measured Mass Flow in Exhaust Port of ERV  4.4 mS through 15cm duct = 0.0777 m/sec3  so 165m3 is removed in 35 Minutes DAS Reports 0.102 mean with the pitot tube in the exhaust duct 

I need to understand this properly I think maybe it will explain whats happening here I don't understand how I get a smaller delta T stale - exhaust than between inlet and fresh, if the temperature boost is a result of heat being exchanged? Checked for leaks and instrumentation. I saw similar phenomenon with the small scale experiment, strange. I need to know why. Given: Q l  = h we  ρ q Δx / 3600  Is it  Δx = difference in  humidity ratio  ( kg h2o /kg dry_air )   causing this reading? Seemingly double the  ΔT  inlet to fresh than stale to exhaust. Curtesy of  https://www.engineeringtoolbox.com/ Latent Heat Flow Latent heat is the heat, when supplied to or removed from air, results in a change in moisture content - the temperature of the air is not changed Latent Heat Flow - SI-Units The latent heat flow due to moisture in air can be expressed in SI-units (metric) as Q l  = h we  ρ q Δx / 3600                                  (2) where Q l  = latent heat flow (kW) h we  =  latent

Live data feed from Hubitat Cloud   

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.

Some 3rd Party Code  GitHub

 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

4 port fan working