Temperature selection: 140F vs 190F vs 210F
The KHT100SS adjustable thermostat covers 140-210F via a knob on the under-sink tank. Temperature selection: 140F is appropriate for warm drinking applications (mulled cider, warm water for health purposes). 190-195F is the standard range for tea preparation (most teas steep optimally at 170-200F depending on tea type) and instant coffee. 210F (near boiling) is for applications requiring actual boiling: pour-over coffee with a gooseneck kettle, instant oatmeal, vegetable blanching. Note that water at 210F is not fully boiling at typical home water pressure -- 100C (212F) boiling at sea level requires the full boiling point. At 210F from the KHT100SS, water will boil in an open container within seconds of being dispensed. Do not dispense at 210F into plastic containers -- use ceramic, glass, or stainless.
Tank recovery rate and household sizing
The KHT100SS 1/3-gallon (42 oz) tank is appropriate for 1-3 adults making 3-5 hot beverages daily. At 210F and 3-cup-of-tea daily usage (each cup using approximately 8 oz of hot water), the 42-oz tank provides 5 cups per full draw-down. After drawing 3 cups (24 oz), the remaining 18 oz maintains the remaining thermal mass and heats the replacement cold water faster than starting from empty. For households making more than 8-10 hot beverages per day, a larger tank (InSinkErator F-HC3300S with 2/3-gallon tank, or Grohe Red with 4-liter/1.06-gallon tank) may be more appropriate.
Energy cost comparison
The Kraus KHT100SS tank maintains temperature in standby mode by cycling the 1500W element. Standby energy consumption: approximately 0.25-0.5 kWh per day (the tank has 0.5-inch foam insulation that reduces heat loss). At $0.17 per kWh, standby cost is $0.04-0.09 per day ($15-32 per year). This compares with boiling an electric kettle twice daily (approximately 0.1 kWh per boil x 2 = 0.2 kWh/day = $12 per year) -- the standby energy cost is similar to daily kettle use at comparable hot water volumes, with the convenience advantage of instant hot water at the tap.