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Habitat blog ERV related articles

 

I I really struggle with using Rule Machine...I feel like it has a steep learning curve for some reason.

Anyways, I have a PurpleAir Sensor (integrated with HE already) to measure the air quality in our house. When one of the values reaches 45, I want to switch on our ERV (it's already a switch in HE). I then want it to turn off when the value reaches 15. I don't want it to turn off if the Master Bathroom fan is on however. (I have a rule that turns on/off the ERV according to that switch state.

Should I combine these into 1 rule? How would it look? The custom attribute used for the sensor will be aqi10.

https://community.hubitat.com/t/control-erv-based-on-aqi-sensor/36656






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Mar 30

My house has an Energy Recovery Ventilator (ERV) which brings in fresh air from outdoors. It has a heat exchanger to capture heat (or cool) from the outgoing air. Until recently, it was controlled by a controller in the family room that allowed me to manually adjust what percentage of time it runs. I run it more when there are more people in the house and less when there are fewer - if I remember to adjust it. Sometimes, I forget to bump it up when we have visitors, or forget to set it back when they leave or when the house is empty for days. I never bothered adjusting it for going to work each day.

https://community.hubitat.com/t/ventilation-control/37043


Mar 29, 2020 — My house has an Energy Recovery Ventilator (ERV) which brings in fresh air from outdoors. It has a heat exchanger to capture heat (or cool) ...
You've visited this page 3 times. Last visit: 22/10/20
May 18, 2020 — The HVAC Zoning App for Hubitat controls a Heating, Ventilation, and Air Conditioning system. Single and Two-stage Forced Air Heating and ...
May 14, 2020 — Wondering if anyone has any recommendations for smart vents. I've owned 9 Keen vents for the last two years and two of them died.
When will there be Flair Smart Vents support? Is the Ecobee3 officially supported? What I am looking for is to have a room smart vent to open or close depending ...
Looking at buying some Keen Smart Vents. Can anyone that has them inform whether having Keen's "smart hub" is "required" to work with integrating to Hubitat.
Apr 21, 2019 — Can anyone that has them inform whether having Keen's "smart hub" is "required" to work with integrating to Hubitat. Or Can each individual Vent ...
1 answer
1 day ago — We have no idea whether [Nick Goodey] is a trained engineer or not. But given the detailed design of this DIY energy recovery ventilator for his ...
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Key words. Orbital habitat, environmental control and life support, ECLSS, heat and water transport, waste heat management. NSS Space Settlement Journal ...
4 days ago — Low cost quiet economical energy recovery ventilation system Arduino Hubitat Elevation based.
You visited this page on 22/10/20.

Oct 1, 2020 — A balanced home heat recovery system using Arduino Hubitat Elevation MQTT Zigbee.
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https://community.hubitat.com/t/ventilation-control/37043


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The Heat Exchanger

  Under construction It took around 6 hours to layer the core Based on a 60 Litre Sistema box with a 400 X 400 X 350 6 mm Coroplast core. The fan speed controller is mounted on the end so it takes a 12V 10 Amp supply from the power system and 2 analogue 0 to 5 V signals for speed demand. The pink foam is a NZ$12 exercise matt which insulates it for both sound and heat quite nicely. 60 Litre Plenum on the vent side See  https://greenwayerv.blogspot.com/2020/10/we-added-60-litre-plenum-on-vent-side.html

Home Ventilation Heat Exchanger

 

The Experiment

First things first an experiment. I had been looking around at various homemade ERV core designs and eventually decided to try a Coroplast design. The experimental core was tiny 12 X 12 X 12 cm  using 3 mm Coroplast Nice isn't it :) 20 80 mm PC cooling fans at a fixed speed four temperature probes. Here is the full scale one around 40 X 40 X 35 cm using 6 mm Coroplast A Wemos D1/R2 for instrumentation sending temperatures via MQTT to Node-Red. I'm was not totally convinced by the numbers but it did definitely exchange significant amounts of heat. I checked the calibration and it was good compared to my multi-meter TC probe. In any case it seems to work even at such a small scale. Never did understand why it seems to gain more heat that it lost from the exhaust steam, checked for leaks there were none. Any way  a hairdryer experiment showed it worked and heat was transferred too so I was happy that it would probably work at a larger scale.

Heat Exchanger Low Ambient 86% Heat Recovery

  Drop on exiting air 2.9C Heating of incoming air 2.5C So 86% of the heat recovered

The ERV Data Acquisition System

  Progress over the weekend with the ERV DAS The 999's are me testing the sensor disconnected response. I have a Pitot tube left over from an RC plane I think I might put it in the inlet air stream Pin assignment in the Arduino sketch DHT dht[ 4 ] = {DHT( 4 , DHTTYPE),DHT( 0 , DHTTYPE),DHT( 2 , DHTTYPE),DHT( 14 , DHTTYPE)}; There are 4 DHT22's inside heat exchanger lid, shown below. Sensor locations Arduino code #include < Arduino_JSON . h > #include < ESP8266WiFi . h > #include < MQTT . h > #define LED_PIN LED_BUILTIN //LED_BUILTIN is built in LED #include "DHT.h" // Uncomment whatever type you're using! #define DHTTYPE DHT11 // DHT 11 //#define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321 //#define DHTTYPE DHT21 // DHT 21 (AM2301) WiFiClient net ; MQTTClient MQTTclient ; const char ssid [ ] = "Network" ; const char pass [ ] = "DF@#$%" ; // the IP address for the MQTT server char MQTTip [ ...

Drivers and Arduino Sketches for ERV Fans Control Testing

  The Hookup For proof of concept seems to run reliably in the lab. I don't want to be up and down ladders to make update I intend keeping the control system in Hubitat so I can tinker to my Hearts content. Boost fan PWM control as well as start relays. The valve position is a separate driver and device in Hubitat, This will use one of the PWM Four boost fans in the ducts for each room inlet. One fan in the two way turbo exhaust valve. The valve position is a separate driver and device in Hubitat, This will use one of the PWM pins on the Wemos and its analogue input for the position pot Hubitat Valve Position Driver import groovy.json.JsonSlurper metadata { definition(name: "Greenway ERV Turbo Valve", namespace: "Greenway", author: "Nick Goodey") { capability "Initialize" capability "Switch" capability "Switch Level" command "on" command "off" } preferences { section("Device...