We have a Regin airbed that we have had for several years. The current comfort layer is 2 1/2 inch convoluted foam. I believe long term, that we would like to get a memory foam mattress. We would like to dip our toe into memory foam by replacing the convoluted foam with a memory foam topper.
My question is should we go with a 2 or 3 inch memory foam topper? I do see a few 2 1/2 inch toppers, but there are many more choices in the 2 or 3 inch size. Is there an issue with slightly compressing the 3 inch to fit into the 2 1/2 cavity or would using less air in the bladder allow more space for a thicker topper?
This would be a matter of personal preference but thicker memory foam layers would isolate you better from the firmness of the support underneath it and if you only have a choice between 2" or 3" I would probably go with 3" which “should” still fit inside your cover although compression may make it a little firmer.
I would also make sure that the memory foam was good quality and suitable for your weight and has the properties that you prefer (there is more about the different properties of different types of memory foam in post #9 here and post #8 here).
Post #3 here and the topper guidelines it links to has more information about choosing a topper (or a comfort layer in your case) and includes a link to a list of the better sources for components and toppers I’m aware of. Some of these should also be able to provide you with a 2.5" topper that may be a better fit and won’t need to be “squished” inside your mattress.