Mod-Con with Convectors?

re8

Will a mod-con gas boiler work well with in-wall fin-tube convector cabinets? I have seen some posts that say that the low temperatures will cause problems, but perhaps that is with something else?

Robert O'Brien

Common misconception

http://www.bnl.gov/isd/documents/28709.pdf

Mark Eatherton

Elitist attitudes...

There are a BUNCH of old school misinformed plumbing/heating contractors out there who don't take the time to study these systems that are under the mistaken impression that the application of a mod con appliance to a traditional high temperature hot water heating system is a gross misapplication.



They are wrong.



When properly applied, installed and programmed, these systems will see a minimum 30% reduction in fuel. If they tell you their experience goes counter to that, they didn't take the time to do the installation right. Plain and simple.



ME

Zman

How low can you go?

I know there are to many variables to be exact. What kind of numbers are you guys using for the heating curve with baseboard. I am assuming the coldest day would be 150 to 180. Are number like 100 working on the warmest?

Jean-David Beyer

What kind of numbers are you guys using for the heating curve with baseboard.

I run 110F into my baseboard until it gets down to 50F outside. From there it slopes up to 135F when it gets to 6F outside. This is a very close adjustment of the outdoor reset curve. I run 2F setback at night and it takes 2 to 4 hours to recover in the morning. If I used that zone more, I would not setback at all. Design temperature is 14F around here. When it is 14F outside, it runs at 131F water.



I could go somewhat lower at the warm end, but then the boiler cycles too often because my modulation will not go down far enough. Runs between 80,000 BTU/hour down to 16,000 BTU/hour and that is not low enough.



I had 14 feet of baseboard installed to replace the 3 feet I used to have in each of two rooms so I could run these lower temperatures.

veissman_Bob

I'm running a mod con w/convectors and finned tube

I'm still dialing it all in but the system is running fine.  1st floor and 2nd floor each have convectors and finned tube on their circuits, basement is all finned tube.  Haven't had any trouble yet other than a flow problem with the second floor...but that was a result of too low system pressure that Icesailor solved for me.  Most times I'm running water temps between 120 and 135, and until last week I wasn't running any night setback - just a straight 68 degrees on all three floors 24/7.



I'm still comparing gas usage against prior years (and correlating it with degree days) but I'm using about 25-30% less gas and the house is much more comfortable than its ever been.  The only donwnside is my electric bill seems to be up about $30 a month, I think because the boiler loop pump is running nearly constantly.  I'm going see about programming it "off" when the boiler isn't running to see if that helps.  The primarily heating loop is a Taco Bumble Bee running at 6-8 watts so that's not a big energy hog.