A heat exchanger includes a plurality of flat, multi-channel heat exchange tubes extending between spaced headers. A first gear is operatively engaged with the motor and has a drive shaft extending from the gear. A sensitivity of the pendulum as to the width direction is higher than a sensitivity thereof as to the forwardbackward directions. The methods and their implementation may reduce didt events otherwise commonly occurring when testing logic elements of integrated circuit devices. A valuation tool, lease improvement calculator, refinancing calculator, capitalization rate calculator, mortgage and amortization calculator, and an affordability calculator can enable a user to make multiple property-related on-line calculations.