Fireplaces have changed a lot over the years, and modern packaged fireplaces have become a common addition to high end amenity type areas and/or personal residences.

Before I move on - it is worth pointing out a newcomer to the market called a "water vapor technology" electric fireplace. If you have not seen these then you have to take a look - they only require a water connection and have no venting requirements (not to be confused with a ventless fireplace). Check them out HERE. These things are new, so I do wonder if there will be any kind of space humidity issues long term. If anyone has experience with long term installations I would love to hear about it.

For a standard gas fireplace appliance there will need to be gas, electricity, and venting. The MEP engineers on the project will very likely stay away from specifying or showing any of the venting on their Drawings. Here are some common questions and answers.

What type of fireplace is recommended?

A direct vent type appliance is recommended. Direct vent just means that the air for combustion is ducted directly into the fireplace, and the flue gases are ducted directly out. No air is taken from the surrounding space, and no products of combustion are discharge the space. The "ducting" is typically a concentric round vent that goes to the fireplace. A concentric vent is a round duct within a duct (air can go in/out the inner/outer layer).

Why will the engineer not show/do the venting on their design Drawings?

Direct vent appliances are product specific. The code (International Fuel Gas Code) references the manufacturer recommendations (length of run, number of bends, etc.). Therefore every installation's requirements is unique to whichever fireplace is specified. You should still ask your engineer to show the vent routing on their Drawings once it is determined - it can be dashed and noted as "by others" but it will at least help with coordination in the field.

Are there any guidelines for direct vent appliance termination locations even if a model hasn't been chosen yet?

Yes, the code does cover that, but still look at the manufacturer recommendations once a model is eventually picked. Here is a link to the CODE SECTION WITH A DIAGRAM showing termination clearances.

What if I want to put a fireplace somewhere and the vent will have to go far?

Many of the appliance manufacturers offer a booster fan option. You will need to coordinate the location for the booster fan. It will end up somewhere inline on the vent routing and will need to have power and be accessible. The booster fan will let you vent further.

Why can't we just use a ventless fireplace? That sounds way easier...

You can, however if you ask your engineer to go on record they will likely not recommend it. If you recall in the first question we discussed where the air came from and where products of combustion went... in a ventless fireplace it is all happening within the room. These appliances have been utilized successfully, however I have also heard bad things. Folks have some strong opinions about it, check out the post and comments in this other BLOG.

If you have any questions about this - or anything MEP related please email me at tlong@engr3.com

ABOUT TREY LONG