Firstly, let me say that I'm not an expert in Cryogel Z so the only information I can give you is the experiences that I've had with the Cryogel Z. In answer to your questions:
1) I can't confirm the exact R rating however to give you two examples of the results we have had:
(a) When the cold plates were first installed in both the fridge and freezer
compartments, prior to the countertop or lids being fitted, the compressors were run for approximately 90 minutes to check the system was working correctly. In that time, both the fridge and freezer
plates began to freeze and the temperatures in the base of the cabinets were approx. -10 to - 12 celsius. The next morning (13 hours later) both plates still had heavy frost over them and both cabinets were still around -8 celsius. Given they had no countertop or lids we thought this was a pretty good example of just how little cold could leach through the base of the cabinets. This was in late Oct so late Spring here in Sydney
(b) The second demonstation of just how well the Cryogel Z works for us was after a 12 day holiday on the boat we emptied and cleaned the fridge & freezer comparments then left the lids open to prevent mould/smells etc. When we returned to the boat the following weekend (6 days later) the freezer plate still had heavy condensation
on the lower half of the plate and the bottom of the cabinet was about 6 degrees (celsius) colder than the ambient temperature. This was in mid summer.
2) We, knowingly, used much more Cryogel Z than we perhaps needed to. We used 10 layers on the base of both cabinets, 6 layers around the fridge walls, 8 layers around the freezer walls, 6 layers dividing the two cabinets and 4 layers in the countertop and lids. We used large amounts of it because we're moving aboard our boat this year as our retirement
and plan to cruise
the tropics for the foreseeable future. Given a rebuild
of our old fridge/freezer system was unavoidable, we decided to do the best insulating job we could. As it stands at the moment, once we've brought the temperatures down to 4 degrees celsius (normal fridge temp) our fridge compressor
doesn't come on for days (6 is the record). In the beginning I would turn temp knob to make the compressor
come on as I thought it wasn't working properly. Our freezer gives us deep freeze temps (-15 to -18 celsius) with no effort (we have no problem keeping ice cream) and no condensation
on the countertop. Both systems together use about 30 amps per day and we have left the system running for several days, while our boat's on it's mooring
, with just the solar panels
and still have full batteries when we get on board.
3) In answer to your question 3, half the thickeness of Cryogel Z would provide substantially better insulation
leaving you with a larger cabinet volume. The Cryogel Z is hydrophobic so condensation doesn't affect it's performance at all and finally, it loses about 2% of it's thermal properties in over 40 years! Most other insulating materials lose about 15% in 5-7 years and continue to lose their thermal properties as time goes on and lastly, any moisture affects their performance substantially.
I'll further add that here in Australia
the Cryogel Z is substantially more expensive than in the US. About AUD$100 per square metre and even given this price
, we have no regrets about using it. Our fridge/freezer system will no doubt out live us (providing we don't sink the boat that is
Sorry that's so long winded, hopefully it's of some help.