13cu kenmore chest feezer real-world energy efficency

This 13cu ft. freezer (model 16342) was sold by sears in 2013, but does not currently seem to be in their catalog. It is/was made by Frigidaire; as far as I can tell they were the only one's to make a 13cu freezer; other company's just put their name on it. So far I like it, but that may be rather moot for you, if it's discontinued.Here I'm interested in how much energy it uses as a function of the ambient room temperature in our enclosed patio (much higher in the summer than winter), which presumably will generalize to other similar models. 

So, for the summer of 2014, which in San Diego was hot, hot, hot (80-90 highs), I measured it at 37 watts/hour, averaged over 33 days). That's 324kWh/year, should the efficiency stay the same year round. I'm betting, however, that it will need less electricity in the winter months, when the room is cooler, though.  The EPA estimate is 326kWh; I'm impressed that they are reporting what seems to be the upper bound. In 2014, however, when I measured over 82 days of summer, I found the watts/hour to be 54, or 476 kwH/year. Much less impressive.

In San Diego, with current electricity prices, that means the freezer will cost about $50 a year to run. I'll update this post once I've been able to test performance at lower temperatures.