90 degree flue

Ive read on the Internet you can't attach a 90 degree connecter and a flue pipe straight up. Is this correct ??

Stuart Ogden : We few. we Proud We merry band of brothers and sisters , only have a few rules to follow , Welcome to Permies.com,and a big welcome to the Wood Stove
and Rocket Forum Threads ! With over 20,000 members, you can come here 24 / 7 and talk to someone who wants to talk about what you want to talk about ! Rule #1 is
play nice ! Usually asking someone to quote their source is regarded as a challenge, a Whisper of ''I don't trust that guy and I am braying it out into the world !''

This really is a limited case, there may be a very special point the person on the internet was trying to make, or poor sentence structure or a moments inattention may have
caused a miscommunication !

I can not think of any reason for such a sentence to be crafted, and I am Soooo glad we have spell check and I can come back and see my deathless prose printed out, often
I have found garbage where I was striving for clarity!

In this one instance I can only say, that I know of No Known reason to worry about stove pipe made-up this way, and could you please quote your source ! I doubt you will ever
be asked to do it again ! For The Good of the Craft ! Big AL !

stuart, a good rule of thumb is no more than 2 90 degree bends for a regular style wood heater, a wood stove (I sometimes call interchange the words too) should really have the best draft possible so trying to limit it to only one 90 degree bend in the flue pipe is a thing to strive for. These are by no means hard and fast rules and as long as your stove will draft, you can tie the flue in a bow knot haha.

the issues I can see (aside from slowing down the draft) is making the flue harder to clean and that you would need to support the flue pipe if it had a horizontal run supporting a vertical run.

when you slow down your draft too much in a conventional wood heater, the smoke can cool before it reaches the end and that will cause quicker buildup of creosote in the flue and a heater/stove that will smoke the house up from time to time.

hope that helps, and no I can't quote my sources haha, just a lifetime of heating with wood and being in one too many homes with a poorly plumbed heater