Welcome to my first blog.
This first one is about an old topic regarding what size liner do you need for that new oil fired boiler or furnace or hot water heater. Nineteen years ago I was pretty excited to see there were situations based upon combustion efficiencies and chimney height where the metal chimney liner could actually be reduced from the size of the appliances actual breech. We all know that the safest practice is to match the size of the breech with the connector and the liner. A no brainer. Well, there are times when reducing that size of a 7" or 6" breech to a 5" liner is real handy. Or how about a 5" breech to a 4" liner. Not only easier to pull but less expensive too!
Back in 1997, the last time I purchased an NFPA 31, there were some combinations that would be applicable to installing a four inch liner for something being fired up to 1.0 gph! How cool. That would work for almost everything that I sell. Guess what? The NFPA folks have changed the charts in Appendix E 2016. I don't know when or why. Apparently something didn't work out. The bottom line to this blog/sermon is to keep up on the codes. I have included the link address if you want to take a look. They let you look at the book online for free. www.nfpa.org (Sorry, the link vanished. IT is just wonderful ,he said sarcastically)
I wonder why? I think everything that was ever known about combustion and condensing was old news in 1997 and subject not change.. So the subject of the blog changed from selling a whole bunch of 4" liners and making everyone's life easier and cheaper for the homeowner to keeping up of the freaking codes. However, if you do have a little .5 gph furnace @ 100 psi making rain in the chimney, check its afue, measure the connector and chimney height, then go to the APPENDIX E NFPA 31. You may be able to use a 4" liner and by golly, I just happen to have a bunch of them.
Thanks for dropping by. I will try to come up with other tidbits from time to time for the good of the order.