Remodeling? Building? How to Choose the Right Gas Fireplace

By Fran Marengo

Just as cars are available in many versions to suit different lifestyles, so are gas fireplaces.   It’s a no brainer” to realize that a two-seater sports car would be unsuitable for a young couple with three children. However the pros and cons concerning the various types of gas fireplaces are not always obvious. Homeowners should thoroughly research the subject in order to choose a fireplace which best suits their long-range needs.   

    Perhaps the first issue would be to decide between a vented or ventless (vent-free) model.  At first glance, the ventless method appears to have all the advantages:

Vent-Free Advantages

■ 99.9% efficiency. All the heat stays in the home – none escapes outside.

■ No pipes to buy, no hole to cut, so the purchase price and installation cost is lower.

■ It is easy to add a fireplace virtually anywhere in the home, even where a vented fireplace would be impossible (for example, on a lower level where there is a bathtub directly overhead).    

    Unfortunately, as in most cases when something seems too good to be true, there is usually a “catch:”

Vent-Free Disadvantages

■ Keeping all the heat in the room is, unfortunately, like keeping the bathwater along with the baby. The exhaust, which is clean as today’s technology permits, still produces measurable traces of carbon monoxide and other residues which remain in the room to be breathed in. (That’s the .1% not accounted for in 99.9%) Those with sensitive noses can smell an odor (fumes other than carbon monoxide). This exhaust may be problematic for those with asthma, allergies or other breathing disorders, and even pregnant women and those with heart conditions (as stated on the vent-free data plate included with every unit by law).

■ Running a vent-free fireplace as a primary heat source 24/7, particularly in today’s tight homes (not recommended), can cause a yellowish sticky film to form on walls and ceilings, and the excess moisture produced can encourage growth of mold and mildew.

■ A malfunction, even something as simple as a log that gets picked up but is not replaced in exactly the correct location, can cause soot to form, which can spread throughout the home, as well as cause dangerous levels of fumes.

■ In order to pass the required clean burning tests, the flame patterns on vent- free is usually not considered as realistic as that on vented models. 

   Although many homeowners prefer vent-free for their low cost and ease of installation, it is a product that will not be suitable for some applications. They are prohibited in bedrooms and bathrooms unless they are 10000 BTU’s or less and are tested and certified for such use. Vent-free manufacturers actually do not recommend using their products for primary heat. Rather, vent-free is recommended only for supplemental or emergency use, and still may not be the best choice in households with either pregnant women, infants, the elderly, or those with chronic illness.  For a detailed article on this subject, see the following website, which also has a link to a related article by Consumer Reports: www.gascoals.net/Default.aspx?tabid=313

What’s the Alternative?

   The alternative  - vented fireplaces – will obviously get rid of all issues related to having to breath in exhaust. However, many consumers shy away from even investigating the possibility of a vented fireplace because they have heard they will lose most of their heat.

Three Methods of Venting

What likely is overlooked here is the fact that there are three distinctive venting methods. Two are mainly “for looks” where for the most part, the heat does escape up the vent pipe.  The first method, called “dual fuel,” is where a vented gas logset is added to a fireplace already capable of burning wood. Typically these models offer the most incredibly realistic flames, but are gas guzzlers. Both the damper and glass doors need to be left wide open while the logs are operating. Since operating costs are high, this inefficient method would be best used  mainly for special occasions, such as Christmas, holidays and family gatherings. The second inefficient method is called either “B Vent” or “Natural Vent.” A firebox is designed around a set of logs which cannot be switched, less gas is burned, and with only a few exceptions, the doors must remain open which also pulls already heated air up the chimney.

Direct-Vent Fireplaces are Efficient

    However, the third method -- called “direct-vent” -- reclaims most of the heat, delivering efficiencies ranging from 75% to 85%. Some “furnace-rated” direct-vents go the extra mile and are actually tested and listed as a gas furnace. Realistically, most of the furnace-rated models should be considered as a “mini-furnace” since few have the capacity to heat homes beyond 1500- 2000 sq ft.

    Direct-vents are glassed in and sealed airtight, with hidden gaskets and seals and use a double vent pipe. The center pipe carries out exhaust, while the space between the two pipes pulls in fresh air to feed the fire.  They can either vent directly to out the wall, if located on an outside wall, or go up though the roof as usual.  The vent pipe typically needs to project only two to four feet out of the roof, and can make long horizontal runs in the attic without affecting the draft.  All in all, the direct-vent method appears to be the method preferred by informed consumers who have done their research .

Direct-Vent Pros

■  No air already heated by either the fireplace or central system can escape through the sealed glass.

■ All exhaust fumes are vented outside and cannot seep into the room.

■ They can be installed in any room, and operated continuously without restriction, with no possibility of creating a film in the home. 

■ Furnace-rated models radiate additional heat into the room with a ceramic glass front.  (Tempered glass is standard).

■ Flames and logs usually have a more realistic appearance than vent-free.

■ Direct-vents have the widest range of optional trims and finishes available, some of which are very upscale

■ If installed on an outside wall, they can vent directly out. This costs less than venting through the roof and works great to add a fireplace for a remodeling project.

Direct-Vent Cons

■ The logset is part of the package and cannot be changed.

■ The glass stays in place for viewing (although various decorative screen door accessories are available, which camouflage the glass)

■ Direct-vents cost more than vent-frees.

    Whichever method you choose, be sure to find an informative fireplace contractor who seems willing to take the time to answer your questions. If you are a do-it-yourselfer, find out if the dealer volunteers technical support as needed after the sale at no extra charge.   If you want to hire out the installation, make sure the installation crews are factory trained and certified.

For more details, contact Fran at Custom Fireplaces & More at 1611 E. Spring St (Hwy 70N), in Cookeville at 800-264-8181.  Hours from 9:00AM to 5:00PM Mon – Sat and by appt, after regular hours.