• Most chimneyless fireplaces are small and cannot provide heat to an entire home.fireplace image by Ekaterina Sidorenko from Fotolia.com
  
  Furnaces that don't use chimneys can save you money in installation and energy use because these systems are generally more efficient in burning wood, gas or propane. Chimneyless furnaces are also the only option for those who live in an apartment building or in a house that does not have a working chimney. These furnaces can either be used to supplement a home heating system of they can provide all of the home's heat.
  
  

High-Efficiency Furnaces

• Almost all modern, high-efficiency furnaces do not require the use of a chimney. Today, these furnaces simply use a small fan to push fumes from the furnace to the outside. This small, but high-powdered fan replaces the chimney and makes the furnace more efficient. Furnaces that are 78 to 82 percent efficient use a steel pipe to push the fumes through, while furnaces that are over 90 percent efficient use a plastic pipe, according to Kansas State University's Engineering Extension.
  
  

Gas and Propane Fireplaces

• Gas or propane fireplaces are ventless, which means that they don't require the use of a chimney to vent smoke. This is because natural gas or propane fires are more efficient than wood burning ones as they produce less smoke. Homeowners install gas or propane fireplaces in rooms that previously couldn't have a fireplace such as in apartments, or in bedrooms or basement dens. Because they don't need to be hooked up to chimneys, ventless fireplaces are easier and cheaper to install.
  
  

Gas and Propane Fireplace Safety

• One common concern for gas fireplace safety is its failure to vent to the outside like wood-burning fireplaces or high-efficiency furnaces. Because of this, it is possible for odorless but toxic carbon monoxide to seep into the home. This is especially possible if you leave the fireplace on for too long or if you have installed it improperly. Homeowners who are concerned about this but who want to own a gas fireplace should install carbon monoxide detectors in their home to help maintain a healthy air environment.
  
  

Gel Furnaces

• Gel fireplaces are much like gas or propane fireplaces except that they burn gel fuel. This gel fuel is made from an alcohol gel and burns so efficiently that no gas or smoke will seep into your room. Get fireplaces produce enough heat for a small room but are not designed as a sole source of heat for a home. Like gas and propane fireplaces, gel furnaces can be placed anywhere in a home and can even be moved from room to room.