i plan on running a 4x1000 watt hps grow with 30 plants hydroponically in 4 gallon buckets. I was wondering what size dehumidifier would i need for this space or if i can avoid a dehumidifier and use other tricks to keep the humidity down to 40%. My grow room is going to be completely sealed. Also is there a way to keep the dehumidifier out of the room so i dont have to deal with the heat it creates? Will the dehumidifier effect my co2 i have running?
I was wondering what size dehumidifier would i need for this space? Because the plants transpire about 99% of the water/nutrients, the amount of water/nutrient your plants recieve is approximately the amount that needs to be removed each day. For example 30 plants recieving 1/2 gallon each is 15 gallons total. 8 pints per gallon * 15 gallons is 120 pints. Assuming the A/C handles 15% of the moisture (30% lights on, 0% lights off), we are down to about 102 pints remaining. If you feed every other day, we can cut this in half to 51 pints per day. Because your room is sealed we cannot use ventilation, as ventilation would reduce CO2. Also, these numbers should be calculated at the peak of the plants growth or the final 2 weeks of flowering. Plan for the worst and you will have the right equipment under all circumstances.
Is there a way to keep the dehumidifier out of the room so i dont have to deal with the heat it creates? Yes and no. No - The heat a dehumidifier creates is a by product of condensation and electricity consumption. A more energy efficient dehumidifer will create less heat because it uses less energy. Yes - A clever trick is to install the dehumidifier overhead or duct it into the top of grow room. Not only does this open floor space and valuable lumens for plants, heat rises and will stay above the plants, but humidity equalizes rapidly. Because warm air can hold more moisture than colder air, the dry heat above the plants will attract moisture. Air conditioners and dehumidifers also work better in warmer air. Long story short, the overhead installs of both air conditioner and dehumdifier will keep excessivley cold and hot air away from plants, but deliver cool dry air to them.
