Hi there not sure who might be interested, but in case someone might be here is a a little controller HVAC air exchanger system based on esp - it using the same configuration as my instant water heater only one extra Dallas digital sensor so 1 analogue and 3 digital plus 2 PWM to control two motors on 2 connected to 2 Fortek ssr-40 DA
in My climate and highly efficient house builds and extremely tight houses one needs to install HVAC air Exchange systems to keep the house air healthy. my air exchanger is connected to a small solar wall to offset heat loss during the exchange in winter months . since you have to exchange your air roughly 3 times per day.
so since my instant water heater controller worked so well- I thought I build one for my air exchanger. depending on what type of motor your system uses this may or may not work for you you need motors that are compatible with being controlled by TRIAC. in my case my system is using a basic induction motor so it work quite well with it. I can adjust down to 10% of out put and the fan will still spin though at 10% it air movement speed is about 1M/S…
here are roughly the M/S air flow rate the percentage duty rate .
10% - 1.1M/S;
70% - 4.6M/S;
90% -5.5M/S ;
it is working reasonably well but it needs more work on it scalar algorithm. as to internal solar wall start temp compared to the external outside air temp, as it differential increases so does the the step precision scale increase ( but over the next few months as it gets much colder I will graph it data then figure out a better scalar algorithm for it), in other words the colder the ambient air is out side the smaller the step increment is for the TRIAC . and the the Warmer the Ambient air the the bigger the step increment.
the reasoning behind it is I do not want to over heat my house to much on a sunny day I would prefer a much higher rate of air exchange . so it will adjust the air flow through the solar wall to match the temp differential I want IE: 10c , so if my house air temp is 22C the incoming air from the solar wall coming in at 32 C. once the the solar wall cools down the fan speed drops to it minimum to create a very low air exchange during night time periods and during Daytime periods the rate of exchange increases dramatically. I also installed a minimum temp shut off so if the output air is colder then x degrees the HVAC system will stop all air exchange until it is warmer or there is enough solar energy to maintain the basic air exchange again…
but here is the a working sketch
the digital sensors are based on the ID of the sensor it based on it hex order - number before alpha
Device 0 Address: 28FF0031211605C9
Device 1 Address: 28FF05D3701604DB
Device 2 Address: 28FFB7DA8B16034B
this is where you get what order they will come up in
good luck have fun…