Hey I've been reading all of these great posts on bud dryers...however i have a question about the heat...is it really necessary?
No, not totally necessary. However, the dryer will work
MUCH faster with a temp controlled warm air source than without.
I mean theoretically if you have no humidity(not a lot) could you keep it in a cooler environment and still have good clean dry bud? and exactly what is too much humidity?
The amount of water that air is carrying out of the percentage it COULD carry at any given temperature is called relative humidity (but you knew that from your research, didn't you?
).
If air is at 100%RH at a given temp, it can pick up no more water (which is why we say it is at 100%, maximum capacity). If you want 100%RH air to be able to pick up water from your buds, you need to drop the RH. The easiest way to reduce the RH is to raise the temp. Graph courtesy of Wikipedia:
Air at even 80%RH is
much more able to pick up water out of your buds than air at 100%. It only takes a rise of a couple degrees C in humid, room temp air (100%RH @ 24-25C) to drop the RH dramatically. The lower the RH and the higher the temperature of the air running through the dryer, the faster it will work. Of course, we must limit temp to 29C to prevent breakdown of THC into non-psychoactive cannabinoids.
i plan on drying in a box setup that will maintain about 65F with around 30% humidity very similar to your setup,
If your dryer's intake air was
always @ 30%RH, a heaterless dryer would work rather quickly, every day of the year. If your dryer is in a place where there is climate control (heating & cooling), it could get by without a heater, no worries. However, drying times increase as temperature drops. It might take a week at 0C/30%, but it'd still work.
I'm not so lucky. Not even the living spaces in my house have any permanent heating systems- just don't need it at the subtropical latitude where I am. However, the place where my op is located usually has higher RH than outside air. A heater for my dryer was necessary in my case, where RH is commonly >80-90%.
though im using 2 small 400cfm intake fans and one 8000cfm exhaust,
Check those figures. Something's wrong. My main exhaust blower for my grow op (250W, 250mm dia centrifugal) shifts 600CFM. 8000CFM would be a wind tunnel!
im hoping for the best without the heat element....I cant imagine it would be any slower if the temps were down, i would have thought the added heat would cause evaporations of the water in the bud and raise humidity....so cooler air would possibly dry it faster....
No, cooler air will not dry faster than warmer air. If it would, clothes dryers would not have heating elements- they'd more closely resemble air conditioners. The reason RH does not build up within the dryer is because the fans are busy shifting moist air out of the thing. Obviously, the dryer would need access to a large free airmass to work properly. You could not shut it in an unventilated closet and expect it to work well.
In a hypothetical case, if you had your choice between drawing air in at 24C @ 50% as opposed to say 16C, also @ 50%, the air at 24C would dry buds mucho faster. Air at 24C can hold much, much more water than at 16C (see graph). Energy applied to water molecules causes them to vibrate faster and separate from other water molecules more easily.
The more energy you apply, the faster the rate of evaporation. This energy can be in the form of heat in the air or motion of air. Fast moving air at 100%RH will still knock some water molecules off of anything damp, but much more slowly than air that has been only very slightly warmed. It really takes very little heat energy to drop the RH of a given sample of air at common room temps.
A few people have built heaterless copies of my dryer. They work, albeit much slower than those with controlled temp heater units. Commonly, folks report that a heaterless bud dryer will take about 6-8 days (dependent upon ambient RH) to finish drying freshly trimmed buds.
