Hvac intake

Originally Posted By: Kevin McMahon
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The gooseneck is the freshair intake for the High Efficiency Furnace. The metal pipe below is the Exhaust for the HWH. Behind the gooseneck (not shown clearly) is the Furnace exhaust which extends a few inches above the top of the gooseneck.


Any comments? Just learning the ropes, but this doesn’t look good to me.


What would your suggestion to the owner be?


This is just a test home for me.






ABC Home Inspection, LLC

Originally Posted By: Susan
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Hi Kevin,


You are absolutely correct, this is wrong. The WH is venting right back into the furnace by way of the fresh air intake. Bvent termination looks too close to chimney etc. The bvent is too close to the FAI as well.

I don't want to be presumptuous, but are all three in the same chimney flue?

Your bad hunch was a great catch....dangerous situation!!

SC

Ps. Most FAIs exit the building horizontally. All the furnace specs. I have seen call for this intake to be installed horizontally. Also, most are PVC (yours in the pic. appears to be also). The bvent may not be far enough away from the PVC? Needs a clearance.)


Originally Posted By: rmoore
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Kevin…


No big deal, but it's better referred to as a combustion air intake rather than fresh air.

First...efficiency (to get it out of the way): The oxygen and other gases content of the combustion gases exiting the water heater flue are definately different than the furnace was designed for. Looks like they would be sucked in for combustion air and drastically affect the effeciency of the furnace. For that reason, I would recommend reversing the goose neck away from the water heater vent.

HOWEVER...that's not the main problem here. It appears that the furnace's plastic inlet and exhaust share the chimney with the water heater flue. I'm pretty sure that the plastic is regarded as a combustible material and it's very doubtful you have the required clearances. This set-up looks very wrong to me. Where was the furnace and why couldn't they vent it through a side wall?

Finally, there is the question of how the chimney is sealed from rain etc. Looks like it's not.

You say this is a test house...friends or relatives? Anyway I think you should advise them to get a HVAC techie around to take a look at this...and not the same one that installed the furnace.


--
Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com

Originally Posted By: Kevin McMahon
This post was automatically imported from our archived forum.



Thank you for the comments.


Here’s a pic of the entry into the chimney flue of the HVAC exhaust vent, HVAC combustion air intake and WH exhaust vent in the basement.


Here’s the story. The original furnace heat exchanger which was installed in 1981 went bad (Lennox pulse G14 of which there was a recall of sorts) so a new furnace was brought in to replace the old. This is basically what drew me to start investigating things about the system.


The house is 65 years old, and the new owner has been living there about 2 years.


I asked the tech about side venting, and he said they vented it out the chimney because the chimney was right there (30" away). Otherwise the vent would be sticking out of the front of the house (eyesore and 8’ away from the furnace). I asked him about the exhaust so close to the intake, and he didn’t think it was any problem. icon_question.gif I didn’t ask about two exhausts side by side with one being a combustible plastic though.


I do have a question. I’ve been trying to locate where it says you cannot have two exhaust flues side by side, nor about the type of material required. I was reading the HVAC Code Check book and it shows a “common vent” system with the WH and Furnace sharing a pvc vent via a wye connection. If they can share a common vent, why can’t they go side-by-side up a chimney flue? icon_question.gif





The spec shows the FAI can be vented directy, indirectly, vertically or horizontally.
And this home is for a close relative.
Thanks again.


--
ABC Home Inspection, LLC

Originally Posted By: ekartal
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Kevin,


The pitch on thte HW vent looks marginal at best from the photo. Also looks like PVC and CPVC used together for a vent?

Erol Kartal
ProInspect


Originally Posted By: rmoore
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Quote:
HVAC Code Check book and it shows a "common vent" system with the WH and Furnace sharing a pvc vent via a wye


Kevin...I think I'm looking at the same picture right now. Does kind of look like a plastic joint. Doesn't say anything about being PVC on mine and I think I can guarantee that it's intended to depict a common metal flue.

It's possible that there will never be enough heat built up to melt or set the plastic pipe on fire. Possible, but I wouldn't want to risk it. It would seem unlikely that they used b-pipe for the WH inside a masonry chimney. Ask the HVAC guy how he has ensured the minimum clearance to combustibles all the way up the chimney. Venting just below and into the intake is a no-brainer. Wrong!


--
Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com

Originally Posted By: ekartal
This post was automatically imported from our archived forum.



Hey Kevin,


Since it's too hard to tell from the photo, I retract my opinion about the HW vent pitch. You had the best look! ![icon_wink.gif](upload://ssT9V5t45yjlgXqiFRXL04eXtqw.gif)


Erol Kartal
ProInspect


Originally Posted By: dvalley
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What’s up with those wide open holes at the chimney penetrations? The insulation is stuffed into those crevices to fill the huge gaping cavities? Not good!


These exposed holes need to be filled back in with brick and sealed tight with surrounding mortar.


--
David Valley
MAB Member

Massachusetts Certified Home Inspections
http://www.masscertified.com

"Some cause happiness wherever they go; others, whenever they go."

Originally Posted By: Rich Clos
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Kevin, I know that this is an old topic, but I had to post this for your education for the future.


FIRST and only, this violtates the Gas Code. You cannot vent the plastic pipe in the same chimney with an atomospheric appliance unless they have an approved B-Vnet material all the way through it. In other words, the Hot water tank needs to have a double wall B-vent before you can do what is done there.

SECONDLY, the code strickly prohibits the combustion air being contaminated. A building inspector or the gas company inspection would red tag this job immediately, and possibly turn the gas off at the curb in our area.

Thirdly, this contaminated combustion air from the Hot Water tank will void any furnace warranty if the factory found out about it.

Rich


Originally Posted By: kmcmahon
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Rich, what if all three came out the top?



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Originally Posted By: Rich Clos
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Hi Kevin,


That I'm not sure on, but I think, not sure, but I think the code states that it would no be legal because the two appliances have to be so far apart when it comes to combustion or fresh air. I have to think this one out or try to get some others to give me data on this.

Rich