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Showing posts with the label data acquisition

Latent Heat Flow and Sensible Heat Flow

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

New Rapid EV Chargers Arthurs Pass

 You can get from Christchurch to Hokatika now in a 30KWh Leaf due to new rapid chargers. The elevation is around 900 meters at Castle Hill Should have plenty of range dropping down into Hokatika around 4.7KWh of gravitational potential, which is around 26 KM of range in the Leaf. Rule of thumb for a Leaf 30 is 1000meters of elevation is 15 to 20% range  from experience. Add caption https://www.omnicalculator.com/physics/potential-energy There's an online calculator for everything nowadays

Live Sensor Data - Via Hubitat cloud

Live data feed from Hubitat Cloud   

Fun fact 1 degree C additional heat exchange from ducting in loft

 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 valve build pictures

4 port fan working

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 [