To get email notification when someone adds to a thread you're following, click on the star in the thread's header and it will turn yellow; click again to turn it off. To edit your profile, click on the gear.
The Wall has a powerful search engine that will go all the way back to 2002. Use "quotation marks" around multiple-word searches. RIGHT-CLICK on the results and choose Open Link In New Window so you'll be able to get back to your results. Happy searching!
In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
3x Oversized ModCon with Concrete Slab, New Home
I'm designing my new ICF home. 2900 ft2 slab heat 3-zones with master/slave zone synchronization.
I did a ResCheck DOE heat loss estimate with my proposed plans & got UA = 400
Location is Cripple Creek Colorado so my design Temp is about -30*F, thus at 70* indoor, my Delta T is about 100* 400 x 100 = 40,000 BTU/hr.
I have a new in box Buderus GB142-45.
Looks like this boiler is about 3x oversized after being derated for 10,000' altitude.
I did the math on my slab, 40yds concrete x 3,800#/yd (with rebar) = 152,000#
With a Specific heat of .2 it will take 30,400 btus to raise the slab 1*f
So at -30* my boiler duty cycle will be about 33%, at freezing (this is a guess) possibly a 10-15% duty cycle?
So my question is: Should I sell the Buderus & buy smaller ModCon OR will slab act like a large buffer tank & Buderus will perform fine with low duty cycles?
0 · ·