VDL Mini Dehumidifier 250ml/day – Compact Dehumidifier for Indoor Grow Tents

Frequently asked questions

• What is the VDL Mini Dehumidifier 250 ml/day actually for?

  To be honest: it's a support unit for occasional use in very small spaces, not a climate control system. It works well in a very small propagation or cutting cabinet, in a drying tent that's already nearly finished, in a storage box, or in a damp corner of a storage room. For a flowering tent it falls short: 250 ml/day is what a single medium-sized plant transpires in just a few hours.

• Why is it so quiet and uses so little power?

  Because it uses Peltier, or thermoelectric, technology, with no compressor. Without a compressor it doesn't vibrate or start and stop with bursts of noise, and its power consumption stays at 23 W. Its noise level is very low, which makes it comfortable if the space is inside your home.

• Can I connect a drain hose or set a target humidity?

  No. This model has no continuous drainage or hygrostat, so you can't set a target humidity percentage, and it doesn't have wheels either. It runs until it fills its 0.9 L tank and shuts off automatically; after that, it has to be emptied by hand. We prefer to be upfront about this before you buy.

• Why do you publish the 250 ml/day figure along with the measurement conditions?

  Because liters/day figures aren't comparable between brands unless they're measured the same way. These 0.25 L/day are measured at 30 °C and 80% RH, very favorable conditions, which is how VDL and Cyclone publish their figures. Quest uses the American AHAM standard at 26.7 °C and 60% RH, which is much more demanding, and the same unit gives a noticeably lower figure under those conditions.

• Can I use it to dry buds?

  No, and it's best to know that upfront. Drying requires maintaining a stable 55 to 62% RH for 10 to 15 days at 18-20 °C with a constant water load, and the Mini has no hygrostat to set that target nor continuous drainage, on top of being limited to 250 ml/day. For drying you need a unit with a hygrostat and continuous drainage.

• How do you size a grow room dehumidifier?

  The most reliable rule isn't square meters, but irrigation water: an indoor grow evaporates almost all the water it's watered with. If you water 10 L a day, the room needs to be able to remove around 10 L a day from the air through extraction and dehumidification combined. Always size it based on liters of irrigation, then adjust for the manufacturer's measurement conditions.