The heat has to go somewhere. It doesn't vanish.
Tell me how plugging in a heater is cheaper than reusing heat you've already had to pay to remove in the first place.
Well I wanted to leave it alone, but since you keep trying the same thing I guess I better explain.
A chiller doesn't make the heat vanish. It only moves the heat from the water into the air. You still need to get rid of it the heat or reuse it. Just like with a radiator. All tests I've seen with cooling have shown that putting in effort to cool the COBs more to gain efficiency costs more enrgy for the cooling. A chiller is just about the most expensive way of moving heat around. For what? 5% extra light for cooling the COBs by 25 degrees C. How about adding 5% more light to begin with and letting the COBs run at a more normal temperature?
If you have some actual numbers how much power chiller is using and that it's actually cheaper than adding 5% to the lights I'd love to hear. Based on just the marketing talk, I'm really not seeing it being more efficient.
You can name a whole list of applications where you might be able to use some excess heat, but lets be serious, you use none of those right? You'd need a load more tech to use it for any of those. Apart from heating the room and a radiator will do just fine for that.
I reuse the heat from the lights for the plants. There is very little left after using that for heating up the whole grow room to the same temperature instead of just the canopy. So no, I don't plug in a heater.