Throat Damper or Top Lock Chimney cap?

[Tim(CT)]

Hi All!,

First timer here... Seeking opinions on which direction I should go. I have an existing fireplace with an existing propane gas line coming in. Fireplace currently has no cap on it and the throat damper is missing the plate. I guess I have two possible directions: 1) Put a mesh cap on the top of the chimney and try and install a new plate (looks like the infrastructure of the throat damper is OK - just missing the plate and the handle) or 2) Install a top lock chimney cap... Our heating fuel is propane so the fireplace gas line is already tied into it and would like to continue to use it. Previous owners took their gas fireplace insert but cannot afford a new one at this point. Was thinking of just putting in a vent-free gas fireplace log set. Much cheaper solution but I do have a small concern about leaving the chimney open (i.e. no throat damper plate) if I go the top lock chimney cap direction. Will I lose all the heat from the gas log set? Any opinions are welcome! Thanks all

 

[DAKSY]

First you will have to size the house-vented log set to the room to ensure adequate combustion air is available. Talk to your hearthshop to determine the correct size. If your room is too small, you will have to leave the damper open BY CODE. Secondly, you will be adding a GALLON of water vapor into your home for every 1000 BTU you burn. If the damper is closed & your home is tight, you will have trouble with windows and doors absorbing that water vapor. They will swell & may not function. Third, if you have any pets, the open flame will burn any shedded hairs & dander & you WILL smell them as they are burnt. The same goes with flammable aerosols...Fourth, people with asthma, other breathing conditions or any pregnant women should not be exposed to home vented appliances.

 

[Tim(CT)]

DAKSY, thank you very much for your reply. But.... what are you telling me? Not sure if you're suggesting to go with a top lock chimney cap or put a plate on my damper. Btw, I had a local fireplace company come into the home and has suggested some different fireplace log sets. And, I they did mention the water in the propane and the humidity levels rising (not the burning of the pet fur and smell though).. Btw, the room is a about 20 x 25 with a vaulted ceiling and open to both a sun room and the kitchen ...

 

[DAKSY]

What I'm saying is that I don't recommend ANY household vented appliance, but it's YOUR call.
Here is a page from a gas log install manual that gives the formula for calculating the size of the
set based on the air volume of the room it is to be installed in.
A lock top damper will probably be the cheaper option & the installer can do that job when the log set is installed...