Why not see if it is practical to put the basement on a separate zone from existing system?

Just a thought.

IMO

You mean mini split heat pump? I don't see why it would not work. Look at Mitsubishi, Panasonic (was Sanyo) and Toshiba web sites for starters.

when I had my new Trane system installed a few years back they said it would not be practical to try to add a zone down there. I think the slim jim is sort of a heat pump but with one fan...correct. I am just unsure if the heat it supplies would make it over the other end of the basement...or what it costs,,,

"when I had my new Trane system installed a few years back they said it would not be practical to try to add a zone down there."

I think it would be wise to go back and revisit this possible solution.

Ductwork modifications might be needed but comfort would likely be better than a mini split considering the L shaped living area. And then there is cost. Hold on tight when you get the price of the mini split.

IMO

that's what I feared...they wanted something like 2K+ if I remember correctly...something about electric dampers, new lines etc etc..I was fearfull the split system would cost as much!

(Maybe some sort of small propane fireplace or something...we have a tank.

I tried fin radiators...if baseboards behave like them then it took forever to heat up. I tried a ceramic fan...that seemed to work better...or I should say it made the area it was pointed at feel warm in minutes...no idea if there is some sort of large scale fan type thing...made me think of slim jim thing...

Propane will be as costly to run as electricity. There is no reason that a mini split can not work well. There are many options. Search on "mini split" or "mini split" and Mitsubishi, Panasonic (or Sanyo) and Toshiba. Look at the equipment, high wall, ceiling cassette, ceiling mount, floor mount.

Cost is difficult to determine, because it depends on installation issues and living costs in your location There is nothing so special about a basement installation. I'd say $2500 minimum. Finding an experienced installer might be difficult. Definitely revisit adding more air flow to the existing system. Adding a "zone" is much more complicated, and expensive than adding more ducts and registers to the area. It would be great if you can find some installers that will look at both both options.

As for L-shaped rooms, I have one room inf my home that has a larger part that is about 15 x 15. There is one 9000 BTU heat-pump, high-wall unit there on wall that you can visualize as the upright part of the L. At the opposite end there is an extension of that room that is about 8 x 8 with two outside walls. The heat pump does not face straight into that extended area. but towards the short wall. In other words, it is not in the corner of the L but halfway down the vertical line. I have no problems heating or cooling that entire area for the last 2 1/3 years. I can get exact measurements if you want.

One advantage of mini splits is the inherent zoning characteristic. You only need to run a particular system, or part of a system when you are in that area. That will save on operating costs. Another advantage is high efficiency, up to SEER ratings in the mid 20s and HPSP 10 and above.

If you go the mini-split route, be sure you get inverter-based equipment. It adjusts to partial load better.

I will look into that system. Thankyou.