Amount of vapor plume in side-vented mod-con

[LakeWhitney]

In replacing an old system in a condo (ca. 1200 sqft), gas boiler with baseboard, we are comparing some mod. con. systems (with indirect HW) and EK's system 2000. A neighbor had a bad experience with a condensing boiler a few years ago.

Our units have no side wall to vent from (you can't vent into your neighbor's basement, right?). It has to vent out the back (condo rules), right under important windows for our view (a major value here). Our neighbor's vent plume drove them to distraction, to the point that they ripped out the condensing & put in a mid-efficiency unit that vented out the flue.

None of the contractors who talked about side-venting mentioned the plume as a potential problem, although when asked about it, they say it's there. A couple of manufacturers, when asked, replied that there is a plume.

How much of a plume would there be? We're in CT, outside New Haven. I imagine it would be more than a dryer, and much more frequent.

Is this a problem that contractors should take note of & draw attention to? I'm surprised we had to chance on a neighbor's experience.

Thanks for your help.

[beenthere]

If the vent is under our window. During low modulation, you will see it.

Why can't you run the PVC up your existing chimney. Then you won't see it.

[LakeWhitney]

Why can't you run the PVC up your existing chimney. Then you won't see it.

Our condos were first apartments, with chimneys shared between pairs of units. We're looking into a liner for EK sys 2000, but running into concerns, e.g., how will a 5" liner affect other possible changes in the future? E.g., what if our neighbor put in a similar unit? Also, a plumber said that such a liner would need a building permit -- first we heard that.

So, while the chimney is possible, it has its problems and we're exploring the side vent.

Can the side vent have its own pvc pipe up the side (perhaps 20-30' but below or at roofline) to avoid windows?

Thanks.

[beenthere]

Shared chimneys have a whole other list of restrictions. So forget lining it, because your neighbor would almost need to also.

The vent can be ran up some on the outside wall. But then you have freezing concerns.