Speaking of messed up venting...

Mike_Sheppard

How about this one. I ran this call last year. Boiler was dumping exhaust into room. CO monitors going off. They had another company come and replace the boiler and water heater vent piping. Comes out of smoke box as 10 inch single wall, connects to the outside wall of 8 inch double wall and runs horizontally all the way out of the building. They cut an opening in the double wall and installed an exhaust fan. I shut them down last year for unsafe conditions. I work for another company now and once again I am back here. Nothing has changed. They fired the boiler back up and ran it all winter.

Steamhead

And your bosses won't let you walk away from that job? That's what I'd do. If the owners don't want to spend the money to do it right, I wouldn't touch it. Too much liability.

Mike_Sheppard

They are on board with walking away from it. I will not leave this boiler running.

The last company I worked for had the contract for these 30 properties. Now the new company I work for has the contract. I am visiting each site evaluating their equipment and operation.

I am going to suggest trashing this boiler and installing two condensing. Perfect application, water source heat pump system. Plenty of room for direct venting right on the other side of the wall. No windows around.

If they don't do that or fix the venting before winter, I will not be turning the boiler on.

Timco

Keith M

Does the water heater actually fire for more than 3 seconds or so?

Mike_Sheppard

Here’s a terrible drawing of what they have there now.

Trying to work this out with the fuel gas code book for vent sizing to see if it can even been done with these sizes and lengths.

Steamhead

Same installers as on those Weil-McLains you posted about earlier?

Mike_Sheppard

@Steamhead I highly doubt it. Today was nothing but messed up systems.

Picture this. Burnham boiler, water source heatpump system. Used a boiler circulator pump and a 3-way valve piped “primary secondary”. 3-way valve maintained 140 degree return temp on boiler. Burnham boiler gets removed, two Lochinvar copper fins get installed. Boiler loop with circulator and 3-way valve left in place, and copper fin boilers piped primary secondary into the other primary secondary. And the closely spaced Ts about 20 feet apart.

Picture attached.

Also, the venting done incorrectly on those copper fins as well. Common vented. No barometrics. Horizontal run longer than vertical. Both running with positive draft. If only one heater is running combustion exhaust flows backwards out of the other. And no rain cap on the top of the vent. Every time it rains water comes out of the casing on the heaters.

Jamie Hall

That's not a terrible drawing, @Mike_Sheppard -- that's a very good isometric. Rare to find anyone who can draw one these days!

Steamhead

Mike_Sheppard said:

@Steamhead I highly doubt it. Today was nothing but messed up systems.



Picture this. Burnham boiler, water source heatpump system. Used a boiler circulator pump and a 3-way valve piped “primary secondary”. 3-way valve maintained 140 degree return temp on boiler. Burnham boiler gets removed, two Lochinvar copper fins get installed. Boiler loop with circulator and 3-way valve left in place, and copper fin boilers piped primary secondary into the other primary secondary. And the closely spaced Ts about 20 feet apart.



Picture attached.



Also, the venting done incorrectly on those copper fins as well. Common vented. No barometrics. Horizontal run longer than vertical. Both running with positive draft. If only one heater is running combustion exhaust flows backwards out of the other. And no rain cap on the top of the vent. Every time it rains water comes out of the casing on the heaters.

Look at the bright side- it is possible to fix that mess, but you can't fix stupid!

STEVEusaPA

Mike_Sheppard said:

Here’s a terrible drawing of what they have there now.



Trying to work this out with the fuel gas code book for vent sizing to see if it can even been done with these sizes and lengths.

I agree, nice drawing.
Are you considering an actual power venter in that drawing or more of a draft inducer, maybe even a chimney top one would do?

EBEBRATT-Ed

@Timco is that combustion air and flue tied together?

EBEBRATT-Ed

It's a mystery why more are not killed by bad venting. Luck?

Mike_Sheppard

> @EBEBRATT-Ed said:
> It's a mystery why more are not killed by bad venting. Luck?

Well when you never enter your boiler room to look at your equipment the CO can’t get ya. Lol

Mike_Sheppard

> @STEVEusaPA said:
> Here’s a terrible drawing of what they have there now.
>
>
>
> Trying to work this out with the fuel gas code book for vent sizing to see if it can even been done with these sizes and lengths.
>
> I agree, nice drawing.
> Are you considering an actual power venter in that drawing or more of a draft inducer, maybe even a chimney top one would do?

To be honest, I don’t know yet. The boiler and burner are old and in bad shape. I’d like to see them agree to install condensing boilers. Perfect application (60-80 degree water) and there’s actually plenty of clearance from windows on the other side of the wall for the venting.

If they don’t go for that then I guess I need to figure out the venting. I’ve been studying the IGFC to prepare for master gasfitting test, I guess this is the time to study venting and figure it out. I’m pretty certain a rooftop exhaust fan would have to be used, Exhausto/Enervex etc. Costly option. The boiler vent piping will have to be changed.

I spent my week vacation at the beach this year reading the IGFC. Need to read it again because I didn’t retain enough.

Timco

EBEBRATT-Ed said:

@Timco is that combustion air and flue tied together?

Yessir, indeed it is. Homeowner attempt at concentric venting...

Mike_Sheppard

> @Timco said:
> @Timco is that combustion air and flue tied together?
>
> Yessir, indeed it is. Homeowner attempt at concentric venting...

Exhaust is warmer so it travels along the top of the vent. Intake air is cooler so it travels along the bottom. Basic physics 🙄🙄🤷‍♂️🤷‍♂️

Henry

According to code, the main vent where the boiler joins with the DHW boilers, should be 14 inches. The draft inducer is a band aid. Is there sufficient combustion air as per NFPA 54?

Henry

Also, we have a 2/3 rule which means your horizontal can only be 2/3 in length of the vertical. The two DHW boiler are supposed to be joined by a 12 Y connection.

Mike_Sheppard

Henry said:

According to code, the main vent where the boiler joins with the DHW boilers, should be 14 inches. The draft inducer is a band aid. Is there sufficient combustion air as per NFPA 54?

@Henry did you size that with the IFGC? If so would you mind elaborating on how you sized it? Trying to understand this better.

There is indeed sufficient combustion air. Surprisingly.

Zman

Mike_Sheppard said:

Here’s a terrible drawing of what they have there now.



Trying to work this out with the fuel gas code book for vent sizing to see if it can even been done with these sizes and lengths.

The drawing is great, I wish I could draw that well.
The content is horrible! I am not sure it is appropriate for the internet

Please keep this post updated when and if you come up with a solution. That's a tough one...

Mike_Sheppard

> @Zman said:
> Here’s a terrible drawing of what they have there now.
>
>
>
> Trying to work this out with the fuel gas code book for vent sizing to see if it can even been done with these sizes and lengths.
>
> The drawing is great, I wish I could draw that well.
> The content is horrible! I am not sure it is appropriate for the internet
>
> Please keep this post updated when and if you come up with a solution. That's a tough one...

Hope you’re being sarcastic. A straight edge a few straight lines lol.

As soon as I fully understand vent sizing out of the IFGC I will come up with something.

I still think losing the boiler and putting in a couple condensing running at 70 degrees would be perfect.

Henry

B149.1 is similar to NFPA 54. The size of the common vent connection must be the same area of both or more vents. Your picture shows a T connection which is not permitted. It must be a Y.

Mike_Sheppard

@henry the connection actually is a Y. I didn’t know how to draw it properly.

Can an exhaust fan and addition of a barometric damper on the boiler make up for the undersized venting? (Venting from boiler to common vent would have to be changed either way).

Henry

The copper fin have a T connection as per your picture

Mike_Sheppard

@Henry oh my bad. I was thinking of the boiler connection rather than the water heater connections. You’re right, they’re both tees. Now that I think if it, I almost never see Y connections anywhere. It’s always T connections.

Steamhead

Mike, that may be because Y connections are not required in your area, as long as the cross-sectional area is big enough. That's true in Baltimore as well- we've never had an inspector call us out on a T connection.

Solid_Fuel_Man

With condensing boilers now, I pretty much have to laugh at those who still want to use high temp boilers on low temp systems and mess with return protection. There are a few exceptions, but very few.

Steamhead

If a cast-iron boiler is piped properly, it will outlast a condensing boiler by at least a decade. I'm sure that figures into a lot of decisions.

Henry

Our code does not permit T nor does your NFPA54. All chimney vent manufacturers will design with Y connections. With an undersized chimney it is easy for combustion gases to come out of an appliance not in use specially with T connections. Been there, seen that, rebuilt the whole vent system.

Mike_Sheppard

I see new installs all the time with T connections that pass inspection like Steamhead mentioned. I’ll have to do some digging on this one.