Hi All,
I had once seen dryer vent kits that were switchable so during colder weather it could be switched to indoor venting to save the heat and humidity inside the house.
I went looking for one of these kits but then found out that they should not be used for gas dryers then I did the forehead slap and said "of course, duh!".

Is there anything available for gas dryers that would help for retaining the heat safely? The dryer is in the basement which is also being converted into some living space and conserving some of the heat in the winter would be helpful as long as it can be done safely.

I think I will be doubling up on the carbon dioxide detectors also.

No, sorry: Only with electric dryers can you get some extra heating inside.

In my opinion, and its only an opinion, but unless you do laundry around the clock seven days a week, bothering with one seems rather pointless.

For example, if I purchased one, it would get used probobly 3 hours out of the week. Considering the heating hours in a regular cold week. I just didn't seem worth it to me.

I may be a little bit hillbilly here, but my idea of how to heat a basement room would be to install a wood stove, then cut a grate in the ceiling of the basement (floor of the ground level) to let that heat travel upstairs.
But that's just me, you know what they say, "different strokes for different folks".

Andrew has a good point. I have a gas dryer and gas hot water. My July gas usage is only a small fraction of my January bill*. Look at CF or therms, not dollars. The gas company recovers as much of their fixed costs regardless of how little gas you use. It seems a shame to blow that warm air outside, and many houses could use the extra humidity too.

Far better to let it go and put your time and money into meticulously sealing up your basement. Run 3 beads of caulk clear around the house. One between the foundation and the plate, and one at the top and bottom of the band joist. Patch any cracks in the foundation. I sealed mine with a cement based paint. Carefully caulk or instant foam around all the pipes and wires that go through the wall. Cold air from the attic can flow down around you pluming vent stack. Seal it and all other pipes and wires where they go through floor above and the where they go through the ceiling to the attic. This will also help reduce condensation in the attic.

I actually have a crawl space, but it is warmer and drier than many basements year around. Water doesn't condense on the pipes down there in the summer.

*Do a search here, and you will find where I claim I use so little gas in the summer that I could never pay off a tankless water heater.