Thinking back to my education on heat flow and such really makes me want to "nerd-out" on the subject. However unless someone here was going to build things for real, I'm not sure how much into detail I would want to get. I find it challenging, because I don't have lots of rabbit experience, so I would have to talk with "rabbit people" to come-up with a compromise design that would be "rabbit compatible" and be a good thermodynamic design.
I would also suggest the the first step before getting too involved in such a setup is to measure the temperature underground. I found temperature probes for 1$-3$ on eBay. If you don't mind long delivery time you can get quite a deal by ordering a bunch. The cheep ones are Celsius only, but you can get a converter app on your phone. You would need to bury a PVC pipe for the probe. Or I suppose you could just make a hole with a t-post and use that hole for the probe.
Preitler":15tw9occ said:
I see two reasons for the cone shape, first is that the less surface area the less heat in the room beneath. The second is that if you make the cover of something heavy so it doesn't heat up fast a big cover might get really heavy. Both issues could be countered if you use something like that sheet metal lined foam used in construction, I use those as hutch cielings.
Err, I might be a person who is pedantic, In saying that I agree with your first statements. However you worded in in a way that makes me cringe. (please don't take this as an insult).
warning: NERD TALK/ENGINEERING SLANG
Warm blooded creatures need to loose heat to live. If a mammal can't loose it will die. If heat loose is not fast enough, the creature will defiantly feel uncomfortable. The ground acts as sort of a way to average temperature out. The ground is cooler in the summer and warmer in the winter (generality speaking). So in the summer, the ground acts as a sort of "heat sink" that the rabbits can dump heat into. In the pyramid design there is greater surface area in contact with the soil, so that could increase the effectiveness of the cooling. I'm just not sure that the increase is great enough to make a real world difference.
I agree with Preitler, I would definitely make the covers white/reflective and possible use insulating material.
From the
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dfr1973":15tw9occ said:
Also, I live in south Florida, so heat will play a large factor in breeding.<snip>not all shade is equal. Have your bunnies under trees if at all possible, as trees' "breathing"/transpiration does actually make a difference.
This is a good reason to grow plants on the embankment. I might even suggest growing (rabbit edible) weeds that cast shade on the cover. Although the underground structure might get in the way of plants getting enough water. So you might need to water the plants during the hottest summer months.
My dislike of the shape is purely a "how to I clean this thing?" point of view. I just imagine having to bend over to clean out "rabbit gunk" Where as removable boxes to me means "pull it out and dump it". Possibly use a ship vac to remove bits that get outside the box. Again since I don't have lots of rabbit experience I would defer to someone with more experience cleaning up after rabbits.
If someone here is seriously wanting to build one of these I would be glad to add my thermodynamic expertise. If no one is planning on building it, the whole discussion is sort of a thought experiment.