Commercial Boiler Code Question

RayWohlfarth

I have a customer looking to replace their low pressure steam boilers. My competition is saying a chimney liner is required by code because it's an old brick chimney. The chimney looks to be in good condition. Do you know of a code that says a linear must be used? I have looked through every code manual I have and have found nothing that requires it.
Thanks in advance.

MikeGordon

Hello Ray;

I believe the International Mechanical Code (IMC) requires all masonry chimneys to be lined. As an example, please take a look at Section 801.16 of the current Michigan Mechanical Code. The Michigan Code, as are many local codes across the country, is modeled after the IMC.

Link to exact code language is here: https://up.codes/viewer/michigan/mi-mechanical-code-2015/chapter/8/chimneys-and-vents#8 Scroll down to section 801.16

In any event, even if it wasn't code required, in my opinion, a masonry liner is a REALLY good idea and best practice. I'd never recommend a modern gas/fuel oil boiler be operated with an unlined chimney.

Hope this helps!


Mike Gordon

EBEBRATT-Ed

When you say brick chimney does it have a clay liner? Or is it a really old unlined chimney? Inside chimney or outside? Oil or gas?

RayWohlfarth

Mike
Thank you so much Thats what I was looking for
Ray

RayWohlfarth

@EBEBRATT-Ed Its an old outdoor chimney

jumper

Can you measure velocity and temperature at top of chimney?
If there is no chance for liquid to condense on surface.....

Mad Dog_2

In NYS, Chimneys with a direct exposure to the outside elements and temperature require a "liner."  Some inspectors say an intact terracotta clay liner suffices. Others will tell you, they want a sleeved "slinky" inserted down the existing chimney and to the breech. Interior chimneys (very old hones usually) if terracotta-clay lined will suffice.  In general, I'm usually going to recommend and insulated stainless steel "slinky."  It can only help.  Mad Dog

RayWohlfarth

@jumper I would need a really big ladder and I would never be able to go that high LOL Thanks
@Mad Dog_2 I think they are looking at a liner or sidewall venting. Thanks

jumper

RayWohlfarth said:

@jumper I would need a really big ladder and I would never be able to go that high LOL Thanks
@Mad Dog_2 I think they are looking at a liner or sidewall venting. Thanks

May be easier to abandon chimney. Blow exhaust through recuperator and new flue.

SteamingatMohawk

Or rent a towable lift that can reach that high ($$$).

RayWohlfarth

@jumper Thats what I was thinking. Just sidewall vent the boilers through the wall next to the chimney
@SteamingatMohawk Can't imagine the price for that

Steamhead

RayWohlfarth said:

@jumper Thats what I was thinking. Just sidewall vent the boilers through the wall next to the chimney
@SteamingatMohawk Can't imagine the price for that

Sidewall venting might be easier said than done. That looks like a walkway next to the building, which IIRC would require a sidewall vent to be 7 feet above grade. At that level you're well into the first floor.

Then there are the additional moving parts required for sidewall venting, which always break down in the middle of winter.

A stainless-steel chimney liner has its merits.

Mad Dog_2

Venting the Rinnais, or any tankless or wall hung boiler is the worst part of the job.  Mad Dog

RayWohlfarth

@Steamhead Good points thanks
@Mad Dog_2 The good part of this is I won't be installing it. I will just sell the boilers

SteamingatMohawk

Hey, maybe you can get a good deal on one of those Chinese spy balloons for an afternoon. Bad joke...LOL

jumper

SteamingatMohawk said:

Hey, maybe you can get a good deal on one of those Chinese spy balloons for an afternoon. Bad joke...LOL

Good joke. Get a guy with a drone to measure temperature & air velocity at top of chimney. If there is enough draft CO2 blows right out without condensing or condensate blows out without eating bricks? I really don't know but I do know that there were unlined chimneys that last decades. Maybe soot protected the masonry then?

Another thing to worry about is ice when boiler is too efficient. How much help is lining for that?

RayWohlfarth

@SteamingatMohawk LOL
@jumper I was told this is over 80 years old.

hot_rod

A building like that may cry out for an engineered flue design. Or a design produced by the manufacturer of the vent material being considered. Selkirk for example.

Intplm.

@RayWohlfarth

Maybe look at a new chimney? Something like a Selkirk type exposed chimney. Abandon the old one.
Might be more cost affective?

RayWohlfarth

@hot_rod Im leaving it up to the owner now. He hired an engineer and I believe they are going with a new flue liner
@Intplm. The owner hired an engineer. Last I heard, they were installing a liner

RayWohlfarth

Thanks everyone I do appreciate it