Improving air flow in Heatilator

[hpcbmw]

My 1970s house has a Heatilator built into the fireplace. It has a small fan that blows into a large open area, then eventually into some pipes that exit the top of the fireplace. It seems that if I got more airflow into the pipes at the top, I would get much better heat transfer from the fireplace into the room. I have pretty limited access to this space without tearing apart alot of the rock facing. I think if I can get a flexible tubing that would attach to the fan, I could then exit the tubing near the pipes at the top of the fireplace. This would force alot more air through the pipes at the top, extracting more heat.

Here's my question- what type of flexible 3" or 4" piping can I get that will hold up to the heat of the fireplace? This old post of mine has pics of my fireplace.

Thanks!

Older fireplace with built in fan and tubes

I just moved into a house that was built in the 1970s. It has a good size fireplace 33wx27hx24deep with some tubes that run through the back and top of it, to blow air out the top, via some cutouts in the fireplace facia. It has 2 small fans, one on each side, on the bottom of the fireplace. One...

www.hearth.com

 

[jetsam]

If you want the fireplace to be a heater, you may be better served by figuring out what kind of insert you can put in it than by trying to get the old heatilator to work better. Even when it was brand new, it was a poor cousin to a wood burning insert.

 

[hpcbmw]

Jetsam, I agree that this is less efficient than an insert, but an insert is going to cost in the $2,000 to $3,000 range or more (used insert, chimney liner, cutting out the old heatilator, etc). This is outside my budget. My utility bill in the winter here in Northern California, using the heatilator, is rarely over $200 per month, so it would take me many years to recoup the cost of an insert.

I have an almost unlimited supply of wood, so efficiency isn't terribly important. The way I use the heatilator, it puts out quite a bit of heat. I hang a small fan in front of the heatilator exhaust tubes to blow the heat into the room. I can easily keep my kitchen and living room at 70 degrees this way. I go through 2-3 cords of pine per year, but as I said, I have plenty of wood to burn from trees I have taken down. I'm just looking for ways to recapture as much heat as possible from my existing fireplace.

Anyone have ideas for flexible piping I can use?

Thanks

 

[jetsam]

Well, they do make flexible chimney liner in 4".

I don't know the internal plumbing of that thing so I can't speculate as to what fan forcing air through it will do.

@bholler has probably seen the insides of lots of them.

 

[hpcbmw]

I found some 3" x 36" piping at Home Depot that says it's rated to 400 degrees for about $12.00. I'm going to give that a try and see if it makes a difference.