Dew point & altitude

Tim Potter

I was reading the “How to obtain the highest amount of condensing!” post
& the corresponding PDF: http://www.fcxalaska.com/PDFs/AshraeCondensingTechnology.pdf
& it got me thinking.

I have an injection mixed, in-floor radiant heating system with a cast iron boiler installed at 9000+ elevation in Colorado. I use the ESBE Thermic valve & 140* element to control return water temps to the boiler.

After reading the post & the PDF, page 40 stood out for me. It shows the condensing temps are lowered from 135* to the 120 - 122*range at 9000’.

My question is: would I see an small increase in efficiency (I realize its not a condensing boiler) by changing the thermostat element from 140* to 122* or would the efficiency stay the same but just lower the supply water temps to the injection system?

Thank You:

Tim

Tim McElwain

I am not clear on what you are asking? Is this a condensing boiler?

nicholas bonham-carter

I believe this in regard to a cast iron boiler, so the condensing may be the kiss of death, due to rusting on the sections.
There are other possibilities for saving ful, however.--NBC

KC_Jones

I think what is being asked is since at their altitude condensing needs a lower temperature, could the cast iron boiler be turned down lower and NOT condense. I don't know the answer, but that is my interpretation.

Zman

I am following your thinking,
I would be careful of playing with the lower end of that one.
If your vent is not in a conditioned space, your boiler may not condense, but the flue sure will. I have seen quite a few rot out when the boiler is set that low or is short cycling.
Carl

Tim Potter

Thank You all for the input.

Zman, The boiler is in the conditioned space, & I do have a boiler buddy, so cycle times are long.

NBC, you summed it up, just pondering "how low can you go"

For the first 15 years of its life, this boiler always condensed being it was directly connected to the infloor radiant. I added the injection & Boiler Buddy