Most want 450-CFM per ton on a heat pump or 1350-CFM on a 3-Ton HP. Install extra large filter racks on the inlet of both Return Air ducts & remove the furnace filter. It is a good idea to Size the Filter Rack(s) for a Free Air Area resulting in a Velocity of 300-fpm or less through the filter area. The large area filter racks are key to adequate airflow. Keep air velocities through the RA Filter(s) as low as possible. Velocity in FPM = Known designed CFM to room divided / by Sq. feet of duct, or open air area of the filter rack area. My Excel ductulator says a 22" or 380-sq.ins., of Return duct for 1350-CFM result is 512-FPM Velocity. However, plenty of airflow is key to proper performance. Use manual D to size the return to meet the 0.5" ESP of the blower for 1350-CFM! Use your own judgment & your tech's judgment, NOT mine! Here is a link that might be useful: Duct Sizing & More

They say the width should be half the size of the table width. Height is not an issue.

Fuzzy, it is true that you can get a counter depth fridge that is 24 cu ft. but since the volume is a product of height, width and depth, if you reduce depth you must increase height and width to keep the same volume. For example, a 36" wide Miele counter depth fridge is 80" tall, costing you the storage you'd have above a standard height fridge, but still has only 18.9 cu ft of storage. To get more volume, you have to go wider, sacrificing cabinets on the sides of the fridge. If you recess a full-depth fridge, you can get the volume without giving up cabinet space. If your kitchen is very large and there aren't space constraints, then it's not an issue.

Currently, we have planned the following for a 4,100 sq ft home (does not include basement). -3 ton ac unit (Lennox 13ACX) -66,000 btu furnace - 96% afue (Lennox EL196UH) -50 gallon water heater - 80% efficient (Bradford White) Who has done the HVAC planning? There seems to be a disconnect between the size of your house and the HVAC equipment. Did the HVAC contractor explain how he came up with these sizes and why only one system for a 2-story 4100 sq. foot house? Bradford White makes several gas hot water heaters. The RC2PV50H6N is 50 gallons with a 0.80 uniform energy (efficiency) factor. It has a 76,000 BTU input, which is more than the proposed furnace. It can produce out 120 gallons of hot water in the first hour. A very nice but expensive hot water heater. You should never run out of hot water with this beast.