I'm in the same boat as the heater is always on lately due to single digit temperatures (and now 8+ inches of snow adding to it). My bug room humidity can range from 20% to about 45% depending on if my humidifier is running.
I use coconut substrate in my nymph cups and was keeping it well misted to ensure the mantis nymphs humidity was always at good levels. Turns out they actually had too much humidity and some of the cups even developed mold. I've since kept the coconut substrate near dry, besides what it soaks up from the mantis misting, and have not had problems with mold or nymphs not having enough water.
Its really strange the nymph cups had too much humidity even in the dead of winter. Too bad there is no way to do a direct probe for humidity like what can be done with a infrared digital thermometer for spot temperature readings. As having hydrometers to know the room humidity even beside the cups is of no use, as I have two.
Best of luck to you working out your humidity.
I really need to get a vaporizer myself... I really do not know if the hot or cold would make a difference.. because once it hits the air.. I think it would cool it anyways...but that is just my opinion... I don't know how much I am off point...
maybe someone else has better insight...
A vaporizer and humidifier are two different things, at least the older models, and depending on which models/brands you buy still.
A vaporizer basically just throws out water as tiny droplets which promptly land nearby and soak anything close to it. The only way it can help with humidity is by the water it throws out slowly evaporating.
A humidifier turns the water to steam allowing the moisture/water to stay in the air, as it turns the solid water to vapor, and really does help with humidity.
I know with my humidifier, the water is turned to a continuous steam cloud instantly. If I fill it with hot water the mist will be very warm, but if I use cold water the mist will be cold as well. It's strange as I would think the steam heat plate would make all the mist come out the same temperature - perhaps it is just the ambient temperature of the water that changes the mist temperature as it leaves the humidifier.
