We put in a direct vent during a remodel several years ago. On the day I turned it on, it smelled and smoked quite a bit, but I expected that. What I didn't know was that our GC cut corners in the installation and didn't install the "firestop." So what I was smelling was actually smoke and burning from a fire in the walls. But, I had no idea and opened the windows to air it out, which fed the fire and our entire addition burned down! Luckily everybody was safe. I am repeating this story because, yes, it can smell, and it is a good idea to run it at a time when you don't care about the smell --- it should be an oily burn off smell, not sure how to describe exactly. If you smell fire though, and have excess amounts of smoke, you might actually have a fire somewhere! I would ideally have it run / tested by the installer / GC.

Andrelaplume2, a few comments. You do not state where you live. I have a similar situation. I have a 20 year-old, 1700 square-foot, all-electric, split foyer home in Baltimore. I have been in the house for 5 years. The heat pump is original Trane (we should count our blessings that they have lasted 20-plus years). I have a masonry fireplace in the below-grade family room. I have allergies (dust, pollen, grass, weeds, cats, etc - I get an allergy shot every 3 weeks and have been doing so since childhood). I have been using my fireplace w/one-of-a-kind wood-burning insert to suppliment the heat pump. The insert raises the temperature of the family room from 65 to 72 degrees. The thermostat is in the living room and set at 68. The layout of the house is not open so the heat does not directly go to the second floor living area (where the thermosat is located) and bedrooms, but it does add BTU's to the house and heats the floor of the living room. The fireplace does not affect my allergies. Neither does mowing the lawn. Are you so sure of the effects of wood-burners on your allergies that you write-off the best sources of heat from your masonry fireplace (wood/pellet insert or stoves)? Propane and electric resistance heat are the most expensive sources of heat - and by a large margin as compared to other sources of heat. I run the house fan in the summer only. This does 2 things. First, it helps to move air in the summer (I have ceiling fans also). Second, the wife doesn't know when the A/C compressor cycles off so there is less of a chance that she is playing with the thermostat. You can run your house fan in the winter with your new heat source and see how it works. I find that there is cold-feeling air blowing out of the vents in the winter time when the firepace is going in the family room (there are no return vents in the family room in the ceiling). Is there a return vent in the ceiling near your fireplace? I agree with Bob Brown from the HVAC Forum that your basement heating should be done with your current HVAC system. When you replace your current heat pump, you can increase it's capacity if needed and add ductwork to your basement. My opinions.

First, DO NOT get a ventless system. Many building codes actually outlaw them. I think they all should because the build up of fumes can be dangerous. Therefore, the choice is between a VENTED gas log system and something called DIRECT VENT system. A vented system works pretty much like your present conventional wood burning fireplace. It will provide some heat, but most of the heat will go up the chimney. It is not an energy efficient system. A direct vent system is comprised of a sealed firebox equipped with 2 vents that go up the chimney -- one to exhaust the fumes and the other to bring in fresh air to feed the combustion. It is very energy efficient, and can give off some serious heat. Direct vent systems are costly and take close to a whole day to install, assuming you already have a gas line in place. You really should consider this option if you want more than just the pleasant appearance of a flame. One more consideration: Since direct vent system can get very hot, it's a good idea to get one with a remote thermostat. Otherwise you'll wind up turning the thing on and off over and over again. But if you live in a climate zone where a kit of heat is not the primary consideration, for instance in Florida, a vented gas log system would be a reasonable option. If a really DRAMATIC dancing flame is what you're looking for, I think the Eiklor brand is the gold standard. But it will use a LOT OF GAS, and most of the heat will go up the chimney. So you're almost literally burning money with that one. I'm partial to direct vent. We have one here in North Carolina, and we love it. Make sure you find someone with a good local reputation to do the installation. Otherwise you'll wind up with buyer's remorse.

Below is a post from 2 years ago on this subject: "posted by: renron on 12.19.2006 at 07:28 pm in Fireplaces Forum First, DON'T install a ventless fireplace!!! Even though the MFG.s will tell you the exhaust fumes are OK, do you really want to breathe them? Many people end up with Major Headaches and chronic breathing issues. Does it sound like a good idea to breathe burnt exhaust gasses? B type flue(vent) pipes are dual thickness pipes. A pipe inside another pipe, suitable for use at 1" or more to flammable materials. Outer casing pipe is sealed and will not conduct air. D (Direct Vent) type flue(vent) pipes are also dual layers but they are capable of exhausting burnt gas through the inner pipe and importing exterior(outside) combustion air for burning. Think of a straw inside a larger straw. Inside straw blowing, outside straw sucking outside air for combustion. A fan is usually used to help exhaust the burnt gasses. Details below: B-Vent (Natural Vent) gas fireplaces are designed primarily for decorative use. Generally they produce a larger and more realistic yellow flame. B-vent fireplaces are sometimes available without a glass window, so many homeowners are attracted to this design because of the open, realistic flame effect; some models do have a glass window so the existence of a window on a fireplace does not define its product classification. Natural vent gas fireplaces use room air for combustion and vent fumes through a vent or chimney that must terminate vertically above the roof line. The key to determining whether a B-vent fireplace will meet your heating needs is to check the manufacturer's listed efficiency rating (gas consumed x efficiency = heat output). While efficient, heater-rated B-vent fireplaces do exist, many lower quality "builder grade" fireplaces have no efficiency rating and, therefore, will not supply substantial heat. In fact, this category of fireplace will often use the greatest amount of gas at the lowest range of efficiencies. If you live in a warmer climate where you want the aesthetics of a fire without much heat, this may be the appliance for you. Likewise, bedrooms and smaller rooms may be a good candidate for a b-vent fireplace, but please check building codes to see if this class of fireplace is approved in your locality or for installation in the room where you'd like to use it. Local/national codes in some areas prohibit the use of b-vent rated appliances, especially in colder climates. Be aware that very "air tight" houses can cause performance problems with b-vent rated appliances, so please consult an experienced fireplace installer who can advise you on the proper installation and use you are considering. Direct Vent Fireplaces offer the most features with respect to gas consumption, efficiency ratings and venting options. A direct vent fireplace will always have a glass window because these fireplaces are sealed systems using a double walled venting system. Combustion air enters the appliance via one section of pipe while fumes and moisture are vented through the other pipe. Most often, a double wall "pipe within a pipe" system is used. Subject to each model's requirements for distance and offsets, direct vent fireplace venting may be terminated either horizontally or vertically. Efficiency rating will average 65% to 84%, similar to ratings on gas furnaces. Keep in mind that these appliances must "waste" some of the heat produced to create a draft of rising warm air to evacuate the fumes produced without aid of a forced air exhaust system. Think of direct vent fireplaces as a decorative furnace: the beauty of a realistic flame with high efficiency. This appliance is great for primary or supplental heating and for emergency backup heating as most work without aid of electricity. Because this is a sealed system that uses outside air for combustion, direct vent fireplaces are usually the favored choice among those in the fireplace industry because of their greater efficiency and exceptionally reliable performance. Hope this info helps, I am a General Contractor. Renron" Good luck. -Gary G