Kenneth Elwell wrote:Your idea of insulating the floor maybe cuts off a resource?
Let's say floor, roof, and walls all have equal surface area... each 1/3 of total, and the floor is insulated. Now the roof is warming up because of the Summer heat, now it is effectively 50% of the area determining the temperature of the room.
There's a man I know in New Hampshire, who just the day before I saw him this one year, had been cutting ice and stocking the local museum's ice house. He was proud of all they had cut and put up, since they had more to do to replace the ice on the floor (ground?), which had been lost over the past year, owing to the previous Winter being too mild to cut much ice, if at all. Ordinarily the ice on the floor stayed year after year, he said.
I guess I'm seeing the floor (and all the dirt below the wofati) as a drain, not a resource. As long as it's warmer than your freezer, it's working tirelessly to melt your freezer. It's not able to work as hard as the summer heat above, but it's still there, sapping away at your frozen ground. At least that's how I am seeing it.
Let's take that same example you give but change from percentages to real made up numbers... Let's say summer heat from above generates 100 units of melting heat, summer heat from the sides generate 40 and the deep earth does 10. At first blush you'd say the floor is only contributing 1/15th of the heat to the freezer. But you insulate the ceiling and walls (umbrella outside the mass) which cuts those numbers by 2/3rds. Now the ceiling of the freezer experiences 33 units from above, 13 from the side and 10 from the floor. Now the ceiling and walls are only heating it during maybe 8 months of the year, in Montana. But the floor is heating it year round. So the annual heat load is 368 (ceiling/walls) plus 120 floor. If the floor was also insulated, it would cut that year round total of 120 down to 40. So the annual total drops from 488 to 408 (20% better). Of course these are made up numbers, and I'm typing this when I can't sleep so I probably did the math wrong, but I think it shows that even a colder floor with constant heat load from below would still contribute a possibly deceptively large amount to heating the freezer.
I wish there was a museum with an ice house around here (need to look in case there actually is). That technology seems pretty cool to me.