Condensing point, modulating boilers and outdoor reset

RS_2

High Efficiency Plume

Can anyone speak to the amount of vent discharge (smokey plume) from wall vented boilers? How close to a neighbor's house would you want to be if he had one?

Mike T., Swampeast MO

It's not smoke--it's water vapor.

The exhaust plume from my Vitodens 6-24 is generally "lazy", e.g. just wafting up from the screen cover.

In extremely cold weather it seems to project about 3'-4' out from the vent.

Above with still conditions or very light wind. In windy conditions, it's carried away from the wind and the vapor cloud tends to dissipate rapidly.

Extremely quiet and in most conditions truly silent. Observed the exhaust on the coldest night last year from about 8' away. It was launching out well and for the first time I actually heard something. (About 4:00 a.m. and VERY still and quiet outside.) I could however hear the nearest neighbor's side vented furnace more loudly and it's about 80' away.

RS_2

Aidan,

Don't you think manufacturers and their engineers would add to value of this forum? They are the ones who have facts to support many of the assertions made here. If you think this group collectively has more info than the manufacturers' engineers and product managers then you are lost. For example, in light of electronic board failures with high efficiency boilers, do you know which board brands and models are most reliable? Do you also know which brands have the lowest MTBFs? Wouldn't that be great info for installers to know so they can minimize installing products that fail rather than merely relying on their limited experience. In fact, I think the Wall should start a spreadsheet that categorizes and saves this kind of data. This would force manufacturers to make better products and fully test products before they are released to the field. There is nothing more lame than field testing products in a customer's house.

Constantin

Don't forget...

... a number of manufacturers have strict policies prohibiting their employees from posting on public furms. This is not limited to the heating sector either.

As for boiler board failures, etc. I suppose we could start a measurement system. However, how to keep it statistically relevant is another question. Not everyone here matains the equipment they install and vice-versa. Furthermore, how to account for installation and maintenance quality? Oh, the questions...

I personally like the current approach better where systematic failures are recognized by several installers, reported, etc. For example, the rash of blower-motor failures in the HTP Munchkin series was eventually resolved by HTP replacing failed motors free of charge and extending the Munchkin warranty.

Plus, no matter how well you test things in the lab, the real world can have some nasty surprises. Note the CPSC recall of 1,700 early WM Ultras because (IIRC) a gas piping connection could have come undone during transportation, for example.

If you only want tried and true hardware, then I suggest you use brands that have been on the market for several years and that have remained largely unchanged in that time. Chances are, the bugs have been worked out.

Trevor Baptista

I am using a WM Ultra boiler which modulates, condensates and uses an ODT reset to adjust outlet water temperatures. The boiler supplies hot water to a hydrocoil in a Trane variable speed air handler. It also provided hot water to a WM Ultra Plus indirect DHW tank. So far the heat has been great. What is anyones opinion on matching this boiler with hydro-air heat?