Improve gas fireplace efficiency

[ratzfatz]

Hi
we bought a house with an old open-vent wood fireplace in which a gas heater was installed. How can I determine whether I have a ventless or vented gas heater?

Assuming it needs to be vented, how can I improve its efficiency without investing a huge sum and without affecting its look too much? The current system looks nice but I assume most of the heat goes up the chimney.

Is it worth installing a metal reflector or heat exchanger? Should/can the damper/throat be configured differently for a gas heater ( I assume it produces less exhaust than a wood fireplace).

I am reasonably DIY competent. I have the tools to cut metal and could imagine doing some simple welding as well.

thanks, Heiner

 

[DAKSY]

Technically, you have a gas log set, not a gas fireplace. It is very inefficient, about - 10 on a scale of 1 - 100. It’s equivalent to having a campfire in your living room. It will give warmth, not heat. There is not an inexpensive means of improving the efficiency. Ceramic glass doors are costly, as is replacing it with a DV gas insert. As far as determining whether it’s vented or vent free, we need to better see the pilot assembly.

 

[ratzfatz]

Technically, you have a gas log set, not a gas fireplace. It is very inefficient, about - 10 on a scale of 1 - 100. It’s equivalent to having a campfire in your living room. It will give warmth, not heat. There is not an inexpensive means of improving the efficiency. Ceramic glass doors are costly, as is replacing it with a DV gas insert. As far as determining whether it’s vented or vent free, we need to better see the pilot assembly.

10% efficiency seems about right! With a ceramic glass door, where does the oxygen get sucked in? Through the chimney? What is the efficiency gain of an inlet over just glass doors? I assume the difference makes the heat exchanger provided with the inlet, right?

The gas logs I have do not have a pilot, I manually light them with a lighter. Anything else I can show you?

If it was vent-less and I close the throat, would it still be as inefficient? (although I don't like the idea of breathing the exhaust)

 

[DAKSY]

10% efficiency seems about right! With a ceramic glass door, where does the oxygen get sucked in? Through the chimney?

No, the combustion air enters thru the pyroceram doorframe.
You need pyroceram to withstand the heat in the firebox.

What is the efficiency gain of an inlet over just glass doors? I assume the difference makes the heat exchanger provided with the inlet, right?

I can't give you an actual number...The door glass is pretty much the heat exchanger via radiation.
That glass can get to 450 Deg. F even in a gas unit. Plus as the fireplace surround material absorbs
heat...

The gas logs I have do not have a pilot, I manually light them with a lighter. Anything else I can show you?

Show me the pilot assembly & the gas valve

If it was vent-less and I close the throat, would it still be as inefficient? (although I don't like the idea of breathing the exhaust)

Vent -free units are misnamed. They are actually ROOM vented. EVERYTHING that gets burned in that unit's
combustion air is also room vented. They are very efficient, but I won't burn one in my home.
There are plenty of others in here that use
them & I'm fine with that.

Hope all those answers make sense!

Edit: if you DO decide to go the pyroceram door glass, all the heat built up in
the firebox might be detrimental to the gas valve...