Improving the airtightness of doors and windows is the key to reducing building energy consumption

With the continuous improvement of people's living standards, the environmental requirements for each family room are also getting higher and higher. The use of air conditioners for cooling in summer and heating or electric heaters in winter has become a necessary condition in people's lives. Therefore, there are about six months of cooling and heating costs in a year, which is a considerable economic expenditure for each family. The energy-saving effect of the airtight performance of the building's exterior windows will directly affect the economic expenditure of your family.

We take the indoor space of a single bedroom as an example to calculate the air permeability. The indoor space has a volume of about 40 cubic meters (length 4,500 × width 3500 × height 2600mm), and the area of ​​the building's exterior window is about 2 square meters (width 1500 × height 1350mm). Calculate the energy consumption of different grades of plastic windows according to the airtight performance grading index value in the national standard GB/T7101 "Airtight performance classification and testing methods for exterior windows of buildings":

The air permeability Q 2 per unit area of ​​a plastic window with Class 1 airtight performance is 18 cubic meters/(m 2 ?h), and the air permeability of a 2 square window per hour is 36 cubic meters. Basically, the indoor air can be made in one hour. Replace all at once.

The air permeability Q 2 per unit area of ​​a plastic window with level 4 airtight performance is 4.5 cubic meters/(m 2 ?h), and the air permeability of a 2 square window per hour is 9 cubic meters. It takes four hours to make the indoor air Replace all at once.

　　 Grade 5 air-tight performance Per cubic meter per hour Q 2 ≤1.5 per hour, while Grade 4 permeability Q 2 ≤4.5, Grade 4 has twice the permeability of Grade 5.

At the same time, we have done the analogy test of different grades of 1# and 2# plastic windows: In a room with a space volume of 48m3 (4m×4m×3m), a refrigeration and heating 1300W air conditioner is used, and 1# sliding window (specification 1500×1500) , Airtight performance level 1, measured penetration rate 16, heat preservation performance K value 3.6) and 2# energy-saving sliding window (same specifications, air tightness level 5, measured penetration rate 1.2, heat preservation performance K value 2.7) respectively. test. In an environment with an indoor temperature of 32°C, and the indoor air conditioner is set to 20°C (normally entering and exiting the office wall without heat preservation), it runs for 8 hours, and the 8 hours power consumption of 1# window airtight performance is 10.73 degrees. And the 8 hours power consumption of 2# window airtight performance level 5 is only 6.1 degrees. It can be seen that the higher the airtight performance, the lower the power consumption. On the contrary, the worse the airtight performance, the higher the power consumption. Energy-saving experts emphasized three years ago that the energy consumption of building doors and windows accounted for 50% of building energy consumption, and the author believes that 50% of the energy consumption of doors and windows lies in airtightness. It can be seen that the real key part of energy-saving doors and windows is air tightness. Increasing the air tightness also improves the sound insulation performance, and greatly improves the water tightness, safety, pollution and dust resistance.

　　 The above data analysis shows that compared with the airtight performance of plastic window grade 1 and grade 4, the penetration rate has increased by 4 times. In other words, the energy consumption of air-conditioning equipment differs by at least 2 times (minus the heat transfer coefficient of the wall). Calculated by a small 1000W air-conditioning equipment, the main body can waste a few dollars in a few hours a day, a small amount of money. The bedroom wastes 200-300 yuan in one year. The temperature difference between indoor and outdoor in the cold northern areas is generally above 30°C (commonly known as: pinholes, big winds), and energy consumption is even more serious. From the perspective of the price difference, the price of ordinary single-glass civil windows is between 150 yuan and 180 yuan per square meter, the price of medium-blank glass engineering windows is between 220-240 yuan per square meter, and the price of patented energy-saving windows is 360 yuan/m 2 , Each square user needs to spend more than 100 yuan, but high-quality energy-saving windows are rarely maintained for 30 years, and inferior windows need at least 200-300 yuan for maintenance. The choice of low-cost, non-energy-saving plastic windows is purely due to small losses.

In the reality that it is generally difficult to improve the energy-saving effect of sliding doors and windows, Jiangsu Province's high-tech product manufacturer—Huai'an Xingfu Doors and Windows Co., Ltd. focused on independent research and development of "health brand" doors and windows and obtained four national utility model patents: "High-strength energy-saving plastics “Profile sliding window sash”, “energy-saving plastic sliding window”, and even the patented energy-saving products used in the overall component profile of “Healthy Brand” sliding window. The assembly is tight, and its wind pressure resistance, airtight performance, watertight performance, and sound insulation performance are all in Above level 4, heat preservation performance is above level 7. The product meets the technical requirements of 65% building energy saving. Tests have shown that in a room using this door and window, each air conditioner can save 2 kilowatt-hours of electricity per day. Based on the national average of 180 days of cooling or heating each year, with two units per household, each household can save 720 kilowatt-hours × 0.6 yuan/kWh per year. It saves 432 yuan in electricity bills, and the quality of energy-saving windows is about 30 years. Each household can save more than 12,960 yuan in electricity bills for 30 years.