kstills wrote:Kaa2 output is ~76k net, which is right about near his current radiation.
I like Keystokers a lot, but to me it looks like there is an inconsistency in the ratings for the KAA-2, as presented on the "Products" page of the Keystoker website, that might explain some of the problem discussed in this thread. For all boilers other than the KAA-2, the "gross" btu/hr value presented corresponds precisely to the values in the "Total Capacity" columns. For example, the 144,000 gross btu/hr shown for the KA-6 is precisely equal to 600 s.f. steam x 240 btu/hr/s.f. steam (i.e., the standard heat transfer rate for steam), and also to 960 s.f. hot water x 150 btu/hr/s.f. hot water (transfer rate for hot water). The same correspondence exists for all of the bigger boilers. This indicates that the "gross" values being reported for those boilers are gross output
For the KAA-2, however, the listed total capacity of 480 s.f. hot water would translate to only (480 x 150=) 72,000 gross output btu/hr. Applying Keystoker's 1.18 pickup factor, the net btu's available to the installed radiation would be about 61k btu/hr. Alternatively, Keystoker's recommended load of 400 s.f. hot water would translate to 60k btu/hr. Either value is quite a bit lower than the 90/76 values appearing in the table, which I haven't found a way to reconcile with the listed capacity values. If, for example, the 90k value was an input value rather than an output value, the rest of the information provided indicates the functional capacity of the unit is around 60k. That would seem to account for much/most of the observed problem.