This paper presents a new rural energy usage mode based on biomass briquette boiler,which integrated cooking, water heating Kang, water heating bed, water heater into a system. The biomass briquette boiler produces hot water with high efficiency and low emission, the hot water can be sent directly into the heating system for room heating, sent into a special water heater for domestic hot water, and sent to water heating Kang or water heating bed for heating and ensure the comfortable of Kang's or bed's surface after reductions of temperature through mixing valve. In order to verify the feasibility and the comfort of thisnewsystem, Airpark software was used to simulate these two living rooms based on the measured data. Simulated the indoor temperature of new heating system room and traditional heating room, analyzed PMV and PPD of these two living rooms, and quantify their thermal comfort. Simulation results show that the average PMV of traditional heating room is around -1.19, while the average PMV of new heating model room is -0.10; and the average PPD of traditional heating room is 39.8%, while the average PPD of the new heating model room is 13.47%. It is obviously that the room with new heating system is more comfortable than the room with traditional heating system. In addition, comparing the economy analysis of these two heating systems, the new one has better economic performance through the life cycle. If this new system be widely used it will produce huge social and economic benefits.

The negative impact of indoor formaldehyde pollution has become a growing interest, especially in severe cold areas, since most residential buildings do not have enough ventilation and people are unwilling to open windows. In order to explore the status and the influencing factors of indoor formaldehyde pollution in severe cold areas and predict the formaldehyde concentrations in these areas, a study of 60 residential buildings in Liaoning, China, was carried out using the method of phenol reagent spectrophotometry. While testing the formaldehyde concentration, the infiltration air change rate of the room was also tested using CO₂ as a tracer gas. The correlation between formaldehyde concentration and its influencing factors was analyzed by SPSS software. Multiple linear regression equations were established for the linear regression analysis. The measured data were used to assess the formaldehyde cancer risk of residents in Liaoning. The test results showed that the most serious rates of average formaldehyde pollution occurred in summer with a concentration of 0.097 mg/m³, and the bedroom was the room most seriously polluted by formaldehyde in autumn with a concentration of 0.104 mg/m³. According to the correlation analysis, the formaldehyde concentration was significantly correlated with the indoor temperature, years of decoration, and the infiltration ventilation rate. The linear regression equation for predicting the formaldehyde concentration was established. According to the risk assessment of the test results, residents in Liaoning are already at risk of cancer caused by formaldehyde.

At present, the most common way for rural heating is conjunction coal-fired boiler with Kang. Due to the economic restriction, the boiler's operation time is limited, which lead to low indoor temperature and poor indoor air quality. Base on this situation, the paper presents a new rural energy usage mode based on biomass briquette boiler, which integrated cooking, water heating bed, water-water heater exchanger into a system. The new model meets the functions of cooking, domestic hot water, heating etc., improving the convenient and efficient of daily life. In order to analyze the feasibility and performance of this new system, a contrast experiment has been made on two houses with basically the same size and structure in Chifeng, to test the bed's surface temperature of new mode, Kang's surface temperature under traditional heating system and their indoor temperatures. The test data show that the bed surface temperature of new mode is 4.2̊C higher than traditional Kang; Indoor temperature of the room with new mode is 5.1̊C higher than the room with traditional heating system; The cooling speed of new mode room is 1.4̊C/h slower than the traditional Kang heating system room during night. The experiment results indicate the thermal performance of new mode is better than traditional mode. What's more, the water-water heat exchanger in new system can satisfy the basic domestic hot water demands, which has a strong practical.

The whole system was simulated by TRNSYS software, and the most suitable volume of the hot water collection tank was first simulated, and then the energy consumption of the system and the COP of the sewage source heat pump unit were analyzed according to the simulation data. The results show that the proportion of energy provided by solar energy in one year is 16.6%, and the proportion of sewage source heat pump units is 58.4%. The energy consumption of gas boilers accounted for 69.3%, the energy consumption of sewage source heat pumps accounted for 29.7%, and the energy consumption of solar sewage source heat pump systems was 174,804.7kWh, with an average energy saving rate of 74.8%. Compared with the original gas boiler system, it saves 375,000 yuan in operating costs, 1263 tons of standard coal and 3473 tons of carbon emissions per year. Outstanding performance, far better than the original gas boiler system.