Hi Jim;

We have discussed your e-mail and the multi-sided fireplaces, that you included - and are recommending the following flue sizes (all measured inside the flue) and the proper size EXHAUSTO Chimney Fan.

36"x32" see-thru - Use 12" flue - Use EXHAUSTO Chimney Fan model RS14
4' wide see-thru - gas - Use 12" flue - Use EXHAUSTO Chimney Fan model RS14
4' wide see-thru - wood - Use 14" flue - Use EXHAUSTO Chimney Fan model RS14
36"x30" 4-sided - gas - Use 10" flue - Use EXHAUSTO Chimney Fan model RS14
36"x30" 4-sided - wood - Use 12" flue - Use EXHAUSTO Chimney Fan model RS14
60" see-thru - Use 18" flue - Use two (2) EXHAUSTO Chimney Fan model RS14 (or 1 RS16)
Corner 36"x24" - Use 10" flue - Use EXHAUSTO Chimney Fan model RS12
Three-sided 3'x3' - Use 16" flue - Use EXHAUSTO Chimney Fan model RS16

As you can see from the above, we're not completely sure about what to recommend for the 60" see-thru fireplace. The RS16 appears to be sufficient, but we want to make sure that this is correct. I will get back with you in regards to this.

Our engineer suggests that you consider using Selkirk-Metalbestos SS-2 pipe (or similar). Do you always recommend clay flues?

We are a little concerned over the small damper opening, which may create turbulence and/or problems with noise. We have had great success in the commercial market with in-line barometric dampers that are interlocked with our fans. However, we do not know whether this installation will meet code requirements for both wood and gas applications.

Sleepy Hollow Chimney Supply manufactures a "spider" damper that works really well with our fans. You can check them out at this link: http://www.bellfiresusa.com/spiderdamper.html

Jim, I hope this answered your questions - but please don't hesitate to call or e-mail if you need additional information.

Regards,

Gitte
EXHAUSTO, Inc.