Based on an analysis of different characteristics between the space-heating load and the domestic water-heating load,a new type of solar combined system is investigated.

Design and analysis on the solar living hot water system in a central heating house;

The pre-conditions and approaches for the recycling of the exhaust heat of air conditioners are expounded and conclusion is drawn that it is feasible to make living hot water by recycling the exhaust heat of air conditioners.

Indicates that the heat pump water heater have obvious energy-saving advantage in supplying living hot water and air-condition.

A solar energy assisted heat pump system for air conditioning,hot water supply and heating are introduced,the experimental work on spring condition to produce hot water is specially discussed.

With the development of the people s living standard, household air-conditioner and hot water have become an indispensable part in our daily life.

The design scheme for preparing domestic hot water by using condensation heat from centralized air-conditioning system is analyzed with engineering example.

With the retrofitting project example in Shanghai area, which adopts the electrical boiler with heat storage system to supply domestic hot water, the paper analyses the initial investment of the retrofitting equipments, operating cost and the recovery period.

The extension of heating period and supply of domestic hot water are a way to improve the economic benefit of heating enterprises,but more heat loss may be caused and stronger alternating thermal stress shock may be produced in the heating system using district heating boiler room or heat and power plant as heat source of centralized heat-supply system.

The economic analysis of centralized hot-water supply mode and the decentralized supply mode by that domestic hot-water is supplied to all consumers with small gas water heaters is made.