Maine Residential Custom Fireplace – Custom Case Study

VGF Custom Fireplaces was approached about designing and fabricating a custom fire feature for a house in Maine. The original design called for a three-sided feature with two linear lines of fire about forty inches long. The visible openings were to be about four feet long on two sides and about two feet on the short side. The unit needed to be glassed-in to facilitate the venting, but there was to be no visible framing around the glass, nor any corner support posts.

The venting for the feature was to come off the top of the structure above the middle of the back wall of the visible enclosure and go straight up approximately twenty feet in a stainless steel tube.

With four feet of an unsupported collection hood and the venting coming off the top, our first challenge was to create an adequate interior support structure. This was accomplished by designing a skeleton frame of steel behind the opening, which was to extend through the hood above the opening. This frame was to be bolted down to the floor. The cantilevered hood had to remain absolutely rigid to not affect the finish applied over it.

The burner footprint was designed to accept the installation of stone slabs so that the flame would look as if it were coming through two slits in the floor. We had to ensure an adequate balance in the supply of primary and secondary air up through the burners to achieve the delicate look of the flame. Once we were set to go, we submitted our shop drawings, schematics and specifications.

After a few months of back forth on the venting support, which the client wanted to be moved directly over the opening, it was ascertained that the cost and complications of adding this additional venting support were problematic. And then, ”Oh by the way, can we vent off the back of the unit, down through the floor, out about twenty feet to a chase, up about fifteen feet into an attic, then another twenty feet out to a side wall?”

We could have worked out the vent and power vent requirements for this but were concerned with creating a trap with the down, out and up path. We suggested a drain trap for this set-up and it was cleared with the project installer.

Finally cleared to go, we went into fabrication and shipped the unit a couple months later. Once the unit had been received there was another slight hiccup. We had designed the unit and burner for use with natural gas and written the specifications accordingly. In fact, the supply fuel was propane and with all the discussion about exhaust and intake venting, this fact had been overlooked. We sent some new orifices with valves that were site adjustable for use with propane.

The VGF custom fireplace team heard nothing for about seven months, then we started hearing from the contractor who was having issues getting the unit to stay on. We initially thought it was a case of venting too fast, pulling off the pilots. We designed a baffle which would slow down the flue gasses exiting the enclosure, but this did not seem to work.

They sent us pictures and we tried a few other things, but frustration was mounting on both sides. In the pictures of the installation that showed the venting and the control set up, we saw some of the best installation work we had ever seen in our years of dealing with installers across North America and beyond. Our discussions revealed their thorough understanding of the set-up. Finally they sent a set of pictures taken from beneath the feature which showed a large shaft leading up into the base of the fireplace and the fresh air make-up being powered into an opening in this shaft.

We ascertained that this sealed-off shaft was creating a pressurized environment: instead of a balanced amount of air being sent into the unit, the unit was being pressurized and the pilot and the flame were being overwhelmed by the pressurized environment. This was rectified and the rest, we hope, is history.

When we saw the pictures of the fire feature and the house, the VGF custom fireplace team could not help being impressed with the obvious quality of the finishes and the clean design. We supply many custom units to projects but when we look at these pictures, we are especially proud of having been part of this project.

Thinking about a custom fireplace?