Susan: Your cheapest source of heat would be a pellet stove but the use of these may be prohibited by the condo association. You have to figure out how much electricity is used per year by the baseboard electric heat to determine your payback time for the cost of a direct vent gas fireplace or pellet stove. Typically, the spring and fall months exclude the use of heat or a/c so these are your baseline months that you can compare to the winter months to see how many additional kilowatt-hours were used for heat. You'll have to include the duration of the entire heating season plus some months where the heat is used only a percentage of the time (you need kw-hrs for the whole year). Once you have all of the additional kw-hrs used for heat, multiply this number by the price of electricity for your area ($.08 per kw-hour in Baltimore). This number is now the price that you paid to heat your condo for the year. Divide the installed price of the gas fireplace (or pellet stove) by the yearly cost of your electric heat and you'll come up with the payback time in years. I'm going to guess that 5 years will be the time that it takes for the gas fireplace (or pellet stove) to pay for itself. Note that the price of natural gas or wood pellets is not included in the above calculation.

Speedmaster- By opening those flaps, you are dumping carbon monoxide into your home. These fireplaces are completely different than the ventfree fireplace you previously had. You should stop that immediately! The cold air is likely caused by lack of proper insulation around the fireplace. It's okay to cover the lower grille when the fireplace is off but the grilles need to be exposed when the fireplace is being used. Not doing so can be a potential fire hazzard. Who did the installation? If a new home, contact your builder who will in turn contact the fireplace subcontractor and insulation contractor for a service call. What specific model do you have? MPD3530.. or MPB3530 etc...What is the room size the fireplace is in? Flat ceiling or Vaulted? Does it vent through the side wall or up through the roof? It's very unusual to hear a direct vent gas fireplace does not produce some level of heat?

Follow up - We finally selected a Mendota model called the Full View 41 (FV41). Most fireplaces have the controls and adjustments on the bottom under the firebox, so there is about a 4"-5" wide piece of trim on the bottom to hide all the mechanicals. However, the Mendota FV models move the controls to the left side, so that the base of the firebox is only about an inch off the floor underneath. It looks much more like the placement of a colonial masonry fireplace. Bruce

Any metal vent pipe from a fire exiting upwards must be enclosed in a X drywalled chase, at a minimum. It’s a vocabulary leap to call that a ”chimney” as it isn’t masonry. But it could be decorated with thin brick or stone to resemble solid masonry. So this could be a ” colloquial terminology” dispute, rather than an actual dispute as to construction details. Always design to the manufacturer’s specific requirements. https://codes.iccsafe.org/content/IRC2015/chapter-18-chimneys-and-vents