It must be remembered that normally the mean rad temperature is conveniently taken as (flowtemp+returntemp)/2, this in turn infers that there is a gradual fall in temperature between the flow and return which can be seen quite clearly in the sketch in both the BOE & the TBOE cases but not in the BTOE case where several temperatures are only in the 40s. To put it another way, when I average the 15 readings in both the BOE & the TBOE and compare them with their mean temps based on (flow+return)/2, one gets (BOE) 60.9 vs 61 & (TBOE) 59.1 vs 59, very close in both cases.
If one compares these numbers in (BTOE) one gets 51.5 vs 60.5, a huge difference (obviously because of the non linear fall in the actual rad temps).
If one accepts this reasoning, then the BOE is the best performing rad and is a (61-20) "41 deg rad"(partly because of the low flow temp of 65C), the next best is the TBOE, a (59-20) 39 deg rad, almost identical (apart from slower warm up) than the BOE.
The BTOE rad is only a (51.5-20) 31.5 deg rad so its performance using the BOE as the bench mark is only outputting (31.5/41)^1.3, ~ 71% of the BOE output?.
If one compares these numbers in (BTOE) one gets 51.5 vs 60.5, a huge difference (obviously because of the non linear fall in the actual rad temps).
If one accepts this reasoning, then the BOE is the best performing rad and is a (61-20) "41 deg rad"(partly because of the low flow temp of 65C), the next best is the TBOE, a (59-20) 39 deg rad, almost identical (apart from slower warm up) than the BOE.
The BTOE rad is only a (51.5-20) 31.5 deg rad so its performance using the BOE as the bench mark is only outputting (31.5/41)^1.3, ~ 71% of the BOE output?.