MGA I would love to see a pic and details of your unit. I have a heatilator and want to improve upon it. Sealing the doors is of interest to me. I am also interested in the grate you refer to. Any internet links?
let's see if i did this ok.....you can see the rope around the door edges. you can get that just about anywhere and it just glues on.
the grate inside is where the logs sit. in the last picture you can see where i added my little invention i'm trying. where the flex pipe ends, there used to be a blower there to blow air inside the grate and thru the pipes the logs sit on, then out thru the bottom under the glass doors.
i didn't like hearing the blower, so i removed it, ran the 4" flex thru the wall and into the basement.from there i hooked up an inducer motor and ran extra flex line to the far bedroom, where i put two wall openings with grills on them.
so....i'm drawing air from the bedroom, under the house and back into the fireplace. the negative air pressure in the bedroom draws the warm air from the room where the fireplace is. i'm just doing the same as a furnace, but in reverse.
the small yellow wire is hooked up to a digital temp sensor and i have another inside the 4" flex so i can monitor the temps in and out. not that i had to, i was curious what they were. normally, i'm pulling 65 degrees into the fire place and the air coming out varies depending on how big the fire is. i've had the air coming out over 350 at times....but the room gets too damn hot...middle of winter and i have to take my clothes off...lol so, i try to keep the fire controlled and often let it almost die out before adding new wood.
the 4" flex is my experiment and if i'm happy with how it works, i'll come up with something a bit more cosmetically pleasing. i'm also working on the blower CFM's. i'm going to try a bigger blower soon that has more CFM's and see if that does any good or not.
the switch to turn the blower on is mounted near the fireplace, so i can turn it on/off at any time. that heat stream has been in service for almost 30 years..believe it or not...has not burned thru at all and is still solid. best investment for the fireplace i ever made.
the glass door frame is also insulted and sealed around the outer edges. i put 1/2" foam insulation so that they would seal tight against the bricks, and there's fiberglass insulation inside the door frame all around.
i sealed the bottom of the door with clear high temp rtv silicone to also eliminate air leaks.
on the negative side, the glass doors will get dirty...more than usual, so, if you like your fire place looking pretty, you might think twice, but i clean mine once a month. they say not to burn a fire with the doors closed, but 99% of the time, my doors are closed and sealed tight.