if something || (or) something not working , also need a timer &&??

Projects Programming
13

The way you wrote your conditional statements actually already implemented a hysteresis -- of sorts. I'd expand on that.

const uint8_t tempHysteresis = 1;
const uint8_t humHysteresis = 5;
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  if (t > (25+tempHysteresis) || h > (70+humHysteresis)) {
    digitalWrite(Relay1, LOW);
  }
  else if (t < (25-tempHysteresis) || h < (70-humHysteresis)) {
    digitalWrite(Relay1, HIGH);
  }

Regarding cross posting in different threads -- that practice is definitely discouraged in these forums.