Summer Heat & Winter In Cab Heat
FWIW, From Experience:
1. Solid, 100% Aluminum Foil tightly sandwiched between two (2) layers of plywood, carpet, steel, cardboard, dense sound materials, or any other solid, opaque material cannot reflect heat and cannot prevent emitting heat without an adjacent air space.
2. A three-quarter inch (3/4") minimum air space immediately adjacent to this aluminum radiant barrier is required for reflecting 96% of the radiant heat or preventing emitting of 96% of this heat. (Can be researched under "Radiant Barriers" ..... this is vintage 1920's technology ...... but aluminum foil was expensive back then.)
3. Aluminum duct tape, securely fastened and taped to the under side of Model A floor boards can reflect about 96% of the heat from a muffler ....... and this same aluminum duct tape taped to the under side of Model A floor boards can also prevent a minimum of 96% of heat emitting from inside the cab in winter.
4. If the undersides of floor boards are thoroughly cleaned and freshly painted, Home Depot Aluminum Duct Tape, (found in A/C Department), securely adhered to this smooth, sanded, and painted wood surface should last for years ..... my duct tape looks like it was applied yesterday ..... but it has already been on the underside of my Model A floor boards for 10 years.
5. Added thermal protection can be provided with an inexpensive thin layer of commercial carpet padding provided and fitted under the floor mat to further prevent muffler heat ...... and further prevent losing inside heat in winter ........ and ..... this carpet padding also provides noticeable engine and roadway sound attenuation for a quieter enjoyable ride.