Looking to convert from vented to ventless - Double sided fireplace

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Ansky

Member
Feb 18, 2013
121
central CT
We currently have a vented propane log set and we want to purchase a ventless unit in hopes that it will be more efficient and put out more heat. Most of the vented sets I see for sale are designed for a traditional one-sided fireplace. Does anyone know of a product that would be more efficient for this application?

Thanks in advance. Here's a pic of current set up.
 

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Speaking as a now retired gas appliance repairman---- DON'T DO IT!

IF EVERY PERSON who uses an unvented fireplace were to READ, UNDERSTAND AND FOLLOW ALL the warnings and limitation routnely described in the installation and operating manuals of unvented equipment, they could be operated safely.

But I never encountered a single installation that could say that. In most cases, people were operating equipment in ways that were unsafe.

The margin of safety with unvented equipment is far more narrow than with vented equipment.

Once I encountered a brand new unvented fireplace that had just been installed by a contractor. The firsttime the brand new homeowner fired it up, they wound up unconscious in the hospital with carbon monoxide poisoning.

I discovered that the contractor had installed the gas logs in an attractive manner, but not in the rather complex way specified in the installation manual. The way it was done generated quite a bit of carbon monoxide.

I wound up giving a deposition when the new homeowner sued everyone in sight.

Before you go further, READ ALL the warnings and limitations on how the fireplace should be operated. Decide if you and your family are willing to follow ALL of those directions ALL the time.
 
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Speaking as a now retired gas appliance repairman---- DON'T DO IT!

.

Thanks for your input. What would you recommend, then, in my case, as a safe way to heat my home using that propane fireplace?
 
The SAFEST way is with a DV gas insert.
Depending on the depth of your see-thru, you may be able to install (2)
inserts in there, back-to-back. There are vent caps available that can
be used to vent (2) units without issues...
If you can't fit (2) in there, pick the side that faces the room where most of
the heat is needed, or the side that allows heat to be moved thru the
rest of your home more easily. The other side can be Temporarily blocked
off with sheet metal, or concrete board or completely bricked up.
 
Daksy's idea of installing direct vent units back to back is an interesting idea. I've NEVER seen such an installation! That would make some fireplace salesman's day, I would suppose!

Gas log sets aren't designed for efficiency at all, they are designed to have an attractive flame appearance. So you have a fireplace that isn't designed with efficiency in mind at all.

See through fireplaces are relatively scarce. Your existing fireplace is very like a "B" vent system, a double wall metal; pipe designed to vent gas appliances. There are probably other see through fireplaces designed to burn gas and use a B vent system that would be more efficient than what you have and safe to install and operate. I'd start by looking among those offering to see if there is something there that you would be happy with.

These would be more efficient than what you have, which is probably something like 10% efficient. But most such gas fireplaces aren't designed to put out a lot of heat, they are usually designed to use a small amount of gas efficiently.

How much do you operate your current gas log system? How much would you like to operate a new fireplace? Unless you are really hot to operate a new fireplace much of the time, I doubt that it would be worthwhile to upgrade considering the expense.

There are gas fireplaces designed to be reasonably efficient and with a big enough burner to provide a good deal of heat. I don't know if you could find such a fireplace in a see through style.

I'd be concerned that you might spend a lot of money taking out something that has an attractive flame and installing something that really wont add all that much heat to your living space. But no harm in shopping around ----there might be something out there that would do a good job for you.

I'd be concerned about some sales rep selling you something that wouldn't be all that much of an improvement, though.

If you find something you like, you might want to post the maker and model here and get some additional opinions on the appliance.
 
Although not the cheapest option. Have you considered ripping that fireplace out and installing a DV zero clearance fireplace?
 
Here's some information which might be accurate and of use to you in making plans:

Usually gas logs are installed in fireplaces designed to burn wood. To burn wood they must have chimney or vents designed to deal with the very high temperatures wood fires can produce.

However, it's possible you have a fireplace designed to burn natural gas fired gas logs, which would then likely be vented with "B" vent, which is designed to vent gas appliances at lower temperatures and lower cost than all fuel class A chimney's for wood stoves.


Your fireplace is almost certainly a manufactured fireplace. It should have a rating plate with the make and model on it. If you post that information we can likely provide you with more information about the fireplace you have and what you can do with it.

Direct vent gas stoves use a pipe within a pipe to bring air for gas combustion into the appliance and then vent the burned combustion gasses out the middle pipe. Direct vent appliances are relatively new form of gas equipment If you were to install a direct vent fireplace you would be abandoning the current venting system in favor of installing a new, two pipe system.

I don't know if there are direct vent see through gas fireplaces. I've never seen one, but they may be out there.
 
I have a similar setup in the house I just bought minus the gas logs and trying to figure out the same thing you are. Just curious, I noticed in your pic that the doors were open and wondered if it makes a difference if you close the doors and adjust the damper?
 
I have a similar setup in the house I just bought minus the gas logs and trying to figure out the same thing you are. Just curious, I noticed in your pic that the doors were open and wondered if it makes a difference if you close the doors and adjust the damper?

Gas logs are installed in a fireplace designed to burn wood. Part of installing a gas log set involves removing or permanently wiring the damper open. The reason for that is to prevent hazardous combustion gasses from being able to enter a dwelling if the damper were closed. With a wood fire, clouds of smoke coming into the house would warn you to open the damper ----that's not the case with gas logs, which can still produce hazardous combustion gasses and water vapor.

So the damper is open!

The glass doors can be good at reducing heat losses up that continuously open chimney. But that only goes so far. They still need to let air in to burn the wood or gas, which means heat losses up the chimney 24/7 whether the fireplace is being used or not.

The only real reason for installing gas logs is that they usually have attractive flames and are a LOT less work than wood. As a heating appliance, they range from being slightly efficient to worse than nothing at all ----primarily because of all that heat loss up the vent.

Every cubic foot of warm air that goes up the chimney has to be replaced by a cubic foot of cold air infiltrating the living space from outdoors.

Fireplaces are almost always miserably ineffcient at heating. The only exceptions are if a wood stove inserts, pellet stove inserts or gas stove insert is installed, which gives you much greater efficiencies of these engineered appliances.
 
Yep totally get the efficiency thing...been heating solely with a BKK in the middle of an open floorplan house for a decade. Found myself in kind of a strange place with a NG line and that double sided fireplace. Don't know whether I should take my primo stash of firewood with me and torch it for firelight or sell it and buy a set of gas logs. Seems like you should just be able to install an outside air kit and put solid pieces of glass on either side.