On Mon, May 20, 2013 at 8:30 PM, Jed Rothwell <[email protected]> wrote:
You can do that from the numbers in Table 8. With average emissivity, > radiation is 460 W and convection is 282. Throw out convection completely > (ignore it; pretend it did not happen) and you get: > > 460 W / 283 W = COP of 1.6 > Here you've used average emissivity. I think a rock-bottom lower bound (or something along those lines) would use ε=1. I do not readily see a way to extract such a calculation for the March 2013 run from the data presented in the paper. Saying there was no heat lost to convection goes beyond conservative. > > Every estimate in this paper is conservative. > Understood. Sometimes its helpful to get a lower bound that is beyond conservative, unless there is universal consensus that an estimate is truly conservative. If there is such consensus, then it will do fine. If reasonable people could cavil, then a lower bound that goes beyond conservative is also useful to have. Eric
