Schmalenbach, D. and Humburg, M., "Optimum Use of Water Heating Systems - New Control Concept in the Heating Systems of Liquid-Cooled Commercial Vehicle Engines, for Optimum Use of the Installed Heating Capacity of Engine-Independent Water Heaters," SAE Technical Paper 920031, 1992, https://doi.org/10.4271/920031.
The level of requirements placed on heater and preheater equipment is extreme, in some cases diametrically opposed, so that additional control and regulation systems have to be used to meet these (following) requirements: 1.Engine preheating at low temperatures (-40 °C) up to the starting temperature. 2.Cab heating at low temperatures up to an inside room temperature (+20 °C). 3.Keeping the cab alone warm in stationary operation with relatively high ambient temperature (+10 °C). The new control and regulation system permits temperature-dependent partial modification of the water volume flows, for example in the motor/cooling water area and in the heating circuit, resulting in a minimization of power losses.An almost loss-free regulation of the blower power for heat transmission to the cab is also operated as a function of the temperature, thereby ensuring comfortable heating-up and heat retention.