Motor vehicle air-conditioning system with coolant circuit circulates coolant by compressor through condenser and heat exchanger to bleed heat to atmosphere from circuit depending on engine and terrain needs.

摘要

When not used to cool the compartment the coolant is circulated through the condenser for increased engine cooling. Heat withdrawn from the coolant in heat exchanger (21) is bled to atmosphere in part at the condenser. The coolant circuit compressor (22) is used to circulate the coolant, with the coolant choking stage ahead of the vaporizer (25) being largely halted. A second choke point upstream of the vaporizer is used to greatly reduce the heat transfer to the coolant by the vaporizer (25). In extreme engine cooling requirements the coolant through the condenser is set so the coolant leaves the condenser above ambient temperature and so transfers heat to the passenger compartment.