Intake/exhaust

[RoBoTeq]

The minimum distance of the vent and combustion air termination is not as important as is the maximum. Do not think that it is best to separate the two more then the specs call for. They need to be in the same pressure zone with the vent above the intake (hot air rises). Even the configuration of whether the terminations point down, up or sideways is not that important as long as vent gases are not directed toward the combustion air intake.

The best way to terminate is with a concentric kit and I must agree that the Trane concentric termination is the nicest looking.

Other issues to consider are things such as wind conditions that can cause pressure into the venting pipe. This can be eliminated by using a "T" at the termination instead of an elbow or by putting a diverter plate across the vent opening like Rheem/Ruud does.

[dx]

No, Robo, apparently the exhaust does NOT need to be above the intake. Read the above posts again. Carrier specifies the exhaust on the bottom, pointed down. This keeps the intake out of the snow and dirt. And the exhaust out of the face of passers-by. And works very well.

[RoBoTeq]

Well, I suppose whatever works. Carrier must have changed its way of venting since I was a Carrier dealer a few years back. I'd like to see the Carrier install manual that shows that configuration.

[coolwhip]

The exhaust points strait out on carriers not down on side wall term. This is on the mvp, mca, mxa models.

[Edited by coolwhip on 08-06-2005 at 08:57 AM]

[RoBoTeq]

There seems to be some confusion about Carrier venting requirements. Does anyone have a link to their instruction manual?

[troyorr]

One of the problems we have in this trade is the reluctance to read manufacturers instructions. Or you could be one of the techs that can't read. For some reason, we are leaning towards a tendency to try and boiler plate everything into one way. A perfect example is the procedure of soldering or brazing linesets. You may be one of those individuals that never learned how to braze. Just because you have been soldering for years, and haven't had a leak, you need to actually open the new installation instructions and read them. LEARN HOW TO BRAZE. I'm the guy that comes behind you and fixes that solder joint you did. As for the question about termination and location of PVC piping, inspectors here want to see the manufacurers installation instructions for proper intallation. If you haven't followed them, no pass. Of course, you have to have an inspection. If you do a retrofit, and don't pull a permit, good luck. I learned the only way to do a job is the right way. The manufacture spends big bucks for engineers to design the system. Why would you think you know more than them? Less liability if installed according to the manufacturer.

[coolwhip]

Originally posted by RoBoTeq
There seems to be some confusion about Carrier venting requirements. Does anyone have a link to their instruction manual?

All which I have mentioned is right out of the installation manual 1994 carrier corp. 58mvp, 58mxa, 58mca.

[RoBoTeq]

But coolwhip, what you have stated is being disputed by dx who feels he is absolutely correct because other posters seem to back up what he has stated. In the meantime, no proof whatsoever has been posted for any Carrier method.

Here is a Goodman installation manual; http://securenet.goodmanmfg.com/pdf/...Lit/IO-244.PDF

Can someone post a similar Carrier installation manual for all of us to look over?

[coolwhip]

Originally posted by dx
Coolwhip is correct. Carrier Weathermaker 58, cca 1992. Exhaust points down, intake points away from wall. Minimum one foot separation (mine is about 18 in.). This is the correct configuration per Carrier. No freezing, no intake contamination, no issues whatsoever. Does not even have screens on either intake or exhaust.

DX, Your installation is incorrect. There is no configuration in venting for the 58mxa, mvp, or mca where the exhaust terminates toword the ground. Whomever piped your system did not follow carriers instructions. I can send you a jpeg if you wish.

[dx]

This is a Carrier 58SXC, cca 1992. If someone has a link to the instructions for this model, we can all see what is correct and what is not.
Without data, it's just an opinion.

[RoBoTeq]

Some opinions are a bit more credible then others, wouldn't you agree?

[Jultzya]

Originally posted by dx
Coolwhip is correct. Carrier Weathermaker 58, cca 1992. Exhaust points down, intake points away from wall.

That is not what coolwhip stated! He said it was the other way around. His post follows....

Originally posted by coolwhip
On carriers, the exhaust is vented with the the elbow pointing strait out and the intake elbow points down.

Originally posted by dx
This is a Carrier 58SXC, cca 1992. If someone has a link to the instructions for this model, we can all see what is correct and what is not.
Without data, it's just an opinion.

Well, I would take a TECH's opinion over a HO'ers opinion most days. And beings that my equipment has never allowed your configuration... I will take coolwhip's opinion!

[vern p]

here is a link I found to Carriers equipment.
http://www.xpedio.carrier.com/idc/gr...lic/documents/

if you know the model # in the technical data you can view as pdf.

[RoBoTeq]

Damn! How is anyone supposed to know what to look at?

I will reiterate my point that vent/combustion air terminations must all follow the laws of physics. In this case there are thermodynamic laws and laws of relative pressure relationships that must be considered.

Aside from it seeming that manufacturers engineers are competing against one another to produce the ugliest termination configurations, they all must still abide by the prevailing laws of physics in their design.

DX; what exactly is it you are trying to accomplish with this thread?

[Jultzya]

RoBo... no kidding!

But, this document show the somewhat normal termination designs.

Which all show the opposite of what dx has stated he has on his unit.

[troyorr]

dx, what answer are you specifically looking for? You aren't an HVAC contractor, just curious, as you have stated and you have been given the proper answer. Follow the furnace manufacturers instructions. That is the only proper answer. Is there anything else you might be curious about that you would like to beat to death too?

[dx]

Yeah, that link Vern gave is a mess. Vern, I did give the model, it's 58SXC (full model #58SXC080-GG). It's not on the link you gave, there is only 58SX files, no SXC. I feel sorry for you if that's where you have to get your literature.
RoBo, the point of this thread was to find out if there is a code provision for how the intake/exhaust should be set up. Most posters have suggested that code simply says to follow manufacturer's instructions. I have no problem with that.

My own system is quite possibly backwards from the Carrier instructions. When it was done (1992), I did verify it against the Carrier drawing, and it did look like they did it right. But it could have been backwards (swapped intake/exhaust) and I may have missed it. Since it's worked flawlessly all these years, I am only curious from the viewpoint of "should I ever hire this HVAC contractor again?"

[Jultzya]

Originally posted by dx
But it could have been backwards (swapped intake/exhaust) and I may have missed it. Since it's worked flawlessly all these years, I am only curious from the viewpoint of "should I ever hire this HVAC contractor again?"

Everybody screws up once in a while, it's how they handle and rectify the situation that would answer that question for me (if, I was in your shoes).

[dec]

I remember years ago when Heil first came out with 90% sealed combustion furnaces . I put in a ton of them in the summer and vented as the manuel said. When winter hit and the temperature got just right one night I had a ton of units that the intakes iced up from the exhaust cristalizing and sticking on the steel screens they gave with them at that time. Got all of them running that night and called the factory the next morning and they informed me to separate the vents a lot farther away then the manuel said. What a pain that was redoing the venting and patching one hole. Kinda of made you look stupid to the homeowners, like you had no idea what you were doing. Im not really big at having them too close together but at least with exhaust aiming out with no elbow helps. Im definately not in favor of going out the roof with both pvc vents. If they do ice up its a lot harder to unplug on an icy roof.

[RoBoTeq]

Originally posted by jultzya

Originally posted by dx
But it could have been backwards (swapped intake/exhaust) and I may have missed it. Since it's worked flawlessly all these years, I am only curious from the viewpoint of "should I ever hire this HVAC contractor again?"

Everybody screws up once in a while, it's how they handle and rectify the situation that would answer that question for me (if, I was in your shoes).

I consider this a perfect answer to the question posed. If we had more builder/contractors as aware of the work being done by their subs as dx is, we would have more consistantly, properly installed HVAC systems.

Dx, there are a lot of installations out there that have been working despite their improper install. I hear it all of the time; "well, it's been working right all of this time so why should it be changed?" The answer to that of course is; "No, it has not been working right, it has been working despite its wrong installation." Some procedures will not show a problem in 99% of the applications and so that 1%er seems to be unique.

Bottom line; install as per the manufacturers installation literature and you will always be within any local code.

Now! Let's not forget concentric kits which seem to defy some of the physics points I have noted, but in reality are a bit of a different animal where the thermaldynamic laws of physics simply behave differently.