Intake/exhaust

[dx]

Vern, I am in Michigan also, and dealing with building departments and inspectors does occasionally remind me of Pluto (not the planet, the other one). And Goofy too.

Don't take it personally. Plenty of bad in my profession also. Based on client comments and what I see, probably a lot more bad contractors than good.

Perhaps things are better in your part of the state. Let me know where and I'll move there

[vern p]

I don't take anything personal dx, I'm in the S.E. part of Mi., north west of detroit, about 40 miles. You haven't updated your profile yet to allow us to know where your at.

[mayguy]

Originally posted by dx
My own house has it with the exhaust pointing down toward the ground and the intake about 18" above it and pointing away from the house.

DX,

Did you mean the other way around??? If your intake is above the exhaust,, you are going to take in the vaper/gas and may freeze inside that pipe.

[coolwhip]

On carriers, the exhaust is vented with the the elbow pointing strait out and the intake elbow points down. It must have a 12in. seperation between the bottom of combustion air and bottom of vent. The intake must be 12in. above the highest anticipated snow level or grade. Whichever is greater. Also 12in. from a overhang or roof. This is for a side wall termination of 12in. or more.

[redcell]

Interesting thread. My new system, installed 1 month ago, has the exhaust pointing down (elbow), and the intake is the sraight pipe. There are 2 bends from the furnace to the wall, but Im sure I have traced them correctly. They are level with each other and aprox. 8-10 inches apart. Do I need to call my installer about the downward pointing exhaust? Did he make a mistake, or is this OK??

[james mo]

There is a good chance your exhaust will recirculate and cause combustion problems and potentially cause an ice buildup on the intake pipe. It was probably an unintentional mistake.

[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.

[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.