Unless you install a direct vent insert into your fireplace, which is expensive and probably overkill for the climate in southern California, gas logs will send most of the heat they produce up the chimney. DO NOT let anyone talk you into a ventless system. They should be outlawed all together, and building codes in many places prohibit them in sleeping rooms. Without a vent, air quality in your indoor space is adversely affected; fumes build up and oxygen is depleted. You might look into the Eiklor brand of vented logs. When we first shopped around before deciding on a direct vent insert, we were most impressed by the Eiklor logs. They produce the most beautiful realistic looking flames, and they have more gas jets than most, which will probably run up your gas bill. If you call their 800#, you might get Mr Eiklor himself to take the call. Because they produce a bigger flame, they probably will throw off more heat into the room, but most of the heat will still go up the chimney. Check out the Eiklor website. If you are intent on really producing some serious heat from your fireplace, a direct vent insert is the way to go, but that will run you at least $4000 installed. Good luck

Assuming your fireplace draws properly, smoke shouldn't be a problem for the existing wood fireplace - though I can appreciate your concern with the new TV, etc. If you're getting smoke in the room; the fireplace isn't functioning properly: learn about draft at http://www.highschimney.com/articles/chimney-airflow-problems/ As for gas logs, you can use vented logs all day vs a limited burn time for ventless logs. The fire will likely be adjusted to have a yellow flame (vs a blue one like your kitchen stove might) so as to look more like a wood fire. That necessarily means that you will have somewhat incomplete combustion. You'll want CO detectors around because if the exhaust isn't going up the chimney as it should be, you won't get any warning (ie no smoke to choke on). You have to put something in place to insure the fireplace damper can never close 100%- a clipboard clip on the damper plate is often used. Your fireplace has to still work for wood, so don't let anyone suggest you have a smaller liner. This is not something you install yourself; a plumber will run the gas line. I'd suggest getting your log set in a hearth store, where they'll cost more no doubt, but you'll also get knowledgeable people and access to professional installation. And you are right: you do lose heat with an open fireplace. I love the official expression for it: "negative heat gain." Here is a link that might be useful: Types of gas firepaces

As part of a livingroom remodel, I converted my wood-burning L shaped fireplace to a gas fireplace. Unfortunately, I didn’t realize until after I had purchased a set of vented gas logs that the logs are not finished on the backside. While the log set looks great from the front, it does not look good or like a real wood fire from the side. The seller of the log set has offered to give me my money back; however, I have been unable to find a log set that is finished on all sides. What kind of vented gas logs do other homeowners who have L shaped or peninsula style fireplaces use? Are there logs that are designed for these types of fireplaces? Any suggestions would be most appreciated.

Blocking those vents is not a good idea in the first place, particularly with a wood mantel. It renders the fireplace unusable. Although I am not aware of any particular building code that states it as being a safety issue, I would think any building inspector would deem it so. Regarding ventless logs, they put out a tremendous amount of heat. So not only is that mantel going to get blasted from behind with heat to those vents, it is going to bet hit with heat flowing directly from the fireplace opening. Here's a clearance chart for mantels for a popular ventless log set that our company sells. I suggest you print this out and do some measuring. I don't think your mantel will pass muster. You may need to replace it with a Non-Combustible Steel Mantel: I can help you with the steel mantel and the logs as well as a way to safely cover those vents that is not noticeable. Let me know if you would like me to present some ideas. I'd do it right now, but it will take more time than I have at the moment.