Carpentry and Woodworking - vent free gas heater installation

Hey,I have 3 gas lines that are capped off in separate bedrooms and living room.living room & my daughter's have a flare with nut screw on the end of it on the gas pipe.The one in my room is just capped and when I measure this cap across the top it is 1 inch so therefore the pipe should be 3/4 right?.So I am assuming all lines are for heaters and same size.What I would like to know is do i just screw the flares off,clean the threads and apply gas compound and screw on a shutoff valve then connect my heaters? also my line is situated in closet(older home),closet probably constructed later, the cap is very close the floor so I will need to add about 33 inches of pipe.Is all I do is screw off the cap and then add a black pipe or galvanized elbow and drill a hole thru the side drywall and put the pipe thru it and then screw on another elbow and nipple,my gas shutoff and then my flex pipe? will this be acceptable by code instead of going beneath into the crawlspace.If i decide to let the gas company do it will they make the installation that way? It will be conveinient so I can hang it on the wall in that area.Last,can you not just hook the heater up to the flare that is already on the pipe but I assume is a no-no without a shutoff but just asking anyways?

Most areas allow the live-in homeowner to do a lot of things on there own, with permits of course. One thing that many do not allow is alteration or repair to gas lines by the homeowner.

That said, I do not like unvented gas heaters. If not adjusted correctly, they may emit carbon monoxide, deadly. Even if working correctly, they emit carbon dioxide and water vapor, and consume the oxygen in the room. Over a prolonged period, this can be bad.

!/2" gas pipe is usually large enough for a room size heater, but all gas feeds require a shutoff valve close to the appliance.

It is true that you will have code restrictions on doing this yourself.
If you do it anyway you would invalidate your homeowners insurance.

I also agree that unvented appliances are a serious potential danger and are not permitted to be used in many jurisdictions.
There are also restrictions on how they are to be used and most have a requirement that they are not to be used unattended.

These appliances are very cheap considering they are claimed to not need a chimney but I would not consider the life of any family member worth saving a few bucks.

Do a search using "unvented space heater dangers" and you will in addition to finding manufacturers claiming they are safe, several government and inspection agency sites warning of the hazards.

Don't use galvanized pipe for gas, use black pipe only. The coating inside galvanized can flake off and clog things up.

I strongly recommend against you doing this yourself. it's just too dangerous working with gas lines without some knowledge and experience. Hire a competent handyman/woman or a pro, or risk suffocating yourself and daughter or blowing your place up!