Hansen's disease, also known as leprosy, is a chronic bacterial disease that primarily affects the skin, peripheral nerves and upper airway.ansen's disease, also known as leprosy, is a chronic bacterial disease that primarily affects the skin, peripheral nerves and upper airway.
1 Direct-vent gas fireplaces cost $1,000 to $3,500, plus $500 to $1,000 for installation. 2  The cost of a ventless gas fireplace is $500 to $2,500, and while there are additional installation costs, you may pay extra for finish work (such as a mantle, marble surround, etc.). The cost of a ventless gas fireplace is $500 to $2,500, and while there are additional installation costs, you may pay extra for finish work (such as a mantle, marble surround, etc.).
Homeowners interested in installing a gas fireplace may need to have a gas line installed. The cost of this can range from nothing, in cases where the gas company installs a line for homeowners purchasing new appliances, to as much as $1,000 for professional installation on a complex project, according to CostHelper.nother conversion method uses top-vented gas fireplace inserts, which may include fans and thermostats. These cost from $1,200 to $2,900, plus another $600 to $1,000 for professional installation.