Flame suite on.. I realize this is normaly a bad idea but hear me out.... electric dyer FWIW

We burn wood so our house is aways really dry in the winter. Whole house humidifier is out due to cost and complicated install. Small humidifiers are a real PITA to deal with. My dryer has a very long vent and would likely dry much more efficiently if vented inside. My vent setup lends well to a simple bypass system that allos some of the vented exhaust inside while leaving the outside vent open so it would be more like a split venting system with some coming inside and some going outside. I figured I could kill 2 birds with one stone.

Yes, I realize that there are down-sides like lint getting in the house and humidity (possibly mold) problems. I plan to mitigate those by making a box with a true airfilter in it so the outcoming air is filtered, not just screened like the dryer. To mitigate the mold I plan to run hygrometers in a few strategic locations (incluidng in the laundry room) to closely monitor humidity levels. If levels get too high I will close off the inside vent, forcin all of the exhaust back outside.

Thoughts?

If you have a lint box on the end of the vent tube you should be good to go, but you may see that there is too much humidity in the house which could promote mold growth.

You're looking for something like this

Dryer heat keeper

They are only for electric dryers since venting gas could result in fumes being pumped into the house.

Not sure how bad the threat really is considering your NG gas range doesn't need to be vented, but there it is.

Yup. I'm renting an ooooolllldddd house, and there is no external dryer vent.  So, we have it exhausting into one of those little lint boxes.  You put like 1 inch of water in it occasionally.  Keeps the lint out of the basement.  We'll see how the humidity levels are in the winter.  So far, we haven't noticed the basement seeming muggy or anything.  But, the AC has run pretty much constantly since we moved in July.

There is no practical way for me to install that in my setup so I will likely just make a box that has a HVAC air filter in it and has a damper that I can close and open. Thats about my only option...

Just add a dehumidifier if it's too damp in the house.  No reason to throw away perfectly good heat.

I just take the hose off the outside vent and clamp a pair of panty hose to the end of it, instant lint trap!!

There used to be a fitting sold exactly for this, but I have not seen one in 20+ years.
It was a flapper style diverted that send the air outside in one position and in the other it went through a 24" X 24" furnace filter, then back into a 8" duct.  You need to route it way from the laundry room, or the humid air will get sucked back into the dryer and prolong drying time (as well as get hotter than hell in there).  
Seem there was an option for capillary tube/bulb to allow it to divert back outside if the house got too warm.

Saw this on the show Shark Tank.
But the valve above is cheaper.
Ive been thinking of doing this.
But we dont have really bad winters in FL.
But every $ saved on the electric bill.......

Yep



 

I do it all the time in the winter.  Sometimes I vent it out for the first 20 min or so thinking the bulk of the moisture is gone by then.  
Of course its also an electric.  It makes me feel better to use that heat and not throw it outside when its 10 degrees out and the furnace is running.

I was going to say the same

I've never owned a dryer, but what about an old cast iron pot full of water near the fire or on top of the wood stove?

This is what my parents used years ago.

It just doesn't put out enough moisture... I've tried it... just doesn't work... Our home hovers around 20% humidity in the winter. The only time I've gotten it near the recommended 35-45% is when we had a bunch of clothes hung up in front of the fireplace to dry. The increased surface area of the clothes brought the humidity up to a perfect level... for a few hours and it just dropped back down as it all redistributed and was absorbed by the home contents...

My current front loading washer spins the crap out of the clothes and they are much closer to being dry.  I dont think there would be too much moisture.

However, growing up my father tied this and we had condensation dripping off all the walls.  I think that was a case of reasonable humidity in the house to begin with and clothes that contained a lot of moisture going into the dryer.

Yeah, HE washers are MUCH better at this... As a matter of fact, if you look at the fine print, there really is no such thing as a HE dryer. The dryer is only HE when PAIRED with an HE washer because the spin cycle on the washers get so much extra water out in the spin cycle...

NOT GONNA WORK

Well darn.

I should have guessed you would have already tried it.