American Hearth and Home


With so many gas products on the market today, it's difficult at times to make the right choice.

At American Hearth and Home, we believe that you should be well informed before making your final selection, whether you purchase from us or another company.

Study the information below and read our Frequently Asked Questions (FAQs) section. You'll find a wealth of knowledge in both sections that will ultimately help you make the right choices.

American Hearth and Home  
1905 Boulevard  
Colonial Heights,  VA  23834  

American Hearth and Home

Vented vs. Vent-Free

If you're looking for maximum heat output and realism that requires no electricity, then vent-free should be your choice. If "looks" are all you want to achieve then vented is your best option. Keep in mind that many of our Vent-Free, Remote Ready & Remote Controlled Log Sets are cross-approved as partially vented or totally vented gas appliances.  This cross approval gives you the best of both Vent-Free and Vented.  Also, and this is important, vent-free gas heating appliances have safety features built-in that will shut the appliance off automatically if something goes wrong—vented do not.

However, some people have justifiable concerns about vent-free. This is partially due to outdated or erroneous articles that have been written about the hazards of indoor air pollution when using a vent-free heating appliance. With all the hype about the dangers, most readers overlook what usually appears in the last paragraph of the article, "Size the BTU output to your needs." This is what most retailers fail to tell you. Most simply give you the maximum dimension requirements for your firebox and that's it. Or they tell you, "Vented or direct vent is the only way to go." If you hear this, look around. Is most, if not all they sell vented or direct vent? I once had a customer tell me that another hearth store told them, "Vent-free will give your dog a headache." We're not sure how to tell if your dog has a headache, unless it asks you for an aspirin.

Over the years we've had many customers who were shopping around - come into our showroom wanting to see a 24" log set. They've measured their firebox and have been to other retailers who told them that a 24" log set is what they need.

Perhaps the first log set they're shown is a 24" Vent-free model with a maximum heat output of 40,000 BTUs. The usual response from the customer is, "That's the one I want and can I get a blower with that?" . . . WRONG!

The first question our staff will ask is, "How many square feet is your home?" Second, "Is your home one story or two?" Followed by, "How old is your home and how well insulated is it?" Then they'll be asked, "How large is the room that your fireplace is in and how many openings (doors) from that room to the rest of the house?" And finally, "Do you have any other gas-fired appliances?" With this information we can properly size the BTU output to the customer's needs.

More than once we've been to a customer's home to evaluate their needs only to find that the fireplace is in a 10' x 12' room with only one opening 36" (doorway) to the rest of the house. Not a good application for a vent-free gas log set that has a minimum output of 24,000 BTUs and a maximum output of 40,000 BTUs at 99.9% efficiency. The old expression, "If a little is good . . . more is better," does not apply here.

With that in mind, here is an explanation and simple formula for determining the right BTU output for a vent-free, gas-fired heating appliance.

Because a vent-free gas heating appliance uses interior air for combustion, the size of the home (square footage), it's age and tightness, and if other gas-fired appliances are used, all play a role in determining the proper size. One final point: if there are other gas-fired appliances but they are in areas of the house that have doors that can be closed, they do not have to be included in the calculation.

Here's an example of how you can calculate the proper BTU output for your application: Three rooms in a house are adjoining with interconnecting passageways but no doors, or the doors will remain open while the vent-free gas heating appliance is in operation; each room has an 8' ceiling. One room is 16' x 12', one is 12' x 12', and one is 10' x 14'. The total volume of the three rooms is 3,808 cu. ft.; (8'x16'x12'), plus (8'
x12'x12'), plus (8'x10'x14') equals 3,808 cu. ft. To be considered unconfined space in this example, the total maximum aggregate input rating of all gas-fired appliances installed in the 3,808 cu. ft. space must not exceed 76,160 BTU per hour; (3,808 divided by 50) x 1,000 equals 76,160 BTU per hour. Obviously, if you do not have any gas-fired appliances, the maximum BTU rating for your application goes up. But this can be a trap that too many people fall into. Remember, more is not better.

Normal air infiltration into a confined space will be adequate to supply the necessary fresh air for proper combustion and ventilation if the building is not constructed unusually tight. If it is tightly constructed, simply opening the fireplace damper approximately one inch will provide adequate combustion and ventilation air. Doing so should still maintain 75% to 85% efficiency of the vent-free gas log set. Furthermore, in those few areas that have yet to approve vent-free gas logs, operating the log set in this manner should meet the code requirements.

Now let's get back to determining the proper log size. The illustration below will show you the three most important measurements.


And finally, if you're not confused enough there's one final element that you must consider: clearances and extensions. But hold on! This is an easy one!

Look at your fireplace. If it's a masonry (meaning "brick") fireplace with a brick chimney and you have a wooden mantel or wood trim or other combustible material surrounding the top of the firebox opening, measure the distance from the underside of the wood mantel to the top of the firebox opening. If it is less than 28", you'll need a heat deflector/hood that attaches to the top of the opening of the firebox.

What's that? Your wife says, "No, it would be ugly!" Not to worry . . . heat deflector/hoods are also quite decorative. They come in flat black, polished brass, and antique brass. They stick out about 4" and deflect all that wonderful heat you'll be getting down and away from your combustible wood mantle or trim. If you have a manufactured firebox and wood mantel or wood trim, a hood is also required if the manufactured firebox does not already have one. Plus, it's a code requirement in most states. The brass hoods DO NOT require polishing—just an occasional dusting.

Hopefully, you've taken the time to read all of the above information, as well as our Frequently Asked Questions  (FAQs) section. Now you're ready to make the correct choice in selecting a Vent-Free Gas Log Set. However, should you have any further questions please e-mail us (it's the fastest way) at

Measuring a typical solid fuel
burning fireplace

a: opening width
b: opening height
c: depth
d: rear wall width

Measuring firebox