As people's living standards continue to improve, the environmental requirements for each family's living space are also increasing. Using air conditioning for cooling in summer and heating with radiators or electric heaters in winter has become a necessary condition in people's lives. Therefore, the cost of cooling and heating for about six months a year is a significant economic expense for every family. The energy-saving effect of the airtight performance of building windows will directly affect your family's economic expenditure.

Taking the air infiltration of a single bedroom as an example, the indoor space volume is about 40 cubic meters (length 4500 × width 3500 × height 2600 mm), and the area of the building's external window is about 2 square meters (width 1500 × height 1350 mm). Now, based on the airtight performance grading index values in the national standard GB/T7101 "Grading and Testing Methods for the Airtight Performance of Building Windows", we calculate the energy consumption of different grades of plastic windows.

The air infiltration rate Q2 for level 1 airtight plastic windows is 18 cubic meters/(m²·h), so the air infiltration for a 2 square meter window in one hour is 36 cubic meters, which can basically replace the indoor air completely in one hour.

The air infiltration rate Q2 for level 4 airtight plastic windows is 4.5 cubic meters/(m²·h), so the air infiltration for a 2 square meter window in one hour is 9 cubic meters, which requires four hours to completely replace the indoor air.

For level 5 airtight performance, the infiltration rate Q2 is ≤1.5 cubic meters per hour, while for level 4, the infiltration rate Q2 is ≤4.5, meaning that level 4 has an infiltration rate that is twice that of level 5.

At the same time, we conducted comparative experiments on different grades of plastic windows 1# and 2#: in a room with a volume of 48m³ (4m × 4m × 3m), using a 1300W air conditioning unit for cooling and heating, we tested the energy consumption of 1# sliding window (specifications 1500 × 1500, airtight performance level 1, measured infiltration rate 16, insulation performance K value 3.6) and 2# energy-saving sliding window (same specifications, airtight performance level 5, measured infiltration rate 1.2, insulation performance K value 2.7). In an indoor temperature of 32°C, with the air conditioning set to 20°C (the normal office walls are not insulated), after running for 8 hours, the electricity consumption for the 1# window with level 1 airtight performance was 10.73 kWh, while for the 2# window with level 5 airtight performance, it was only 6.1 kWh. This shows that the higher the airtight performance, the lower the electricity consumption; conversely, the poorer the airtight performance, the higher the electricity consumption. Energy-saving experts emphasized three years ago that the energy consumption of building doors and windows accounts for 50% of the building's energy consumption, and I believe that 50% of the door and window energy consumption is related to airtight performance. Therefore, the key part of door and window energy saving lies in airtightness. Improving airtightness also enhances sound insulation performance and significantly improves water tightness, safety, and resistance to dirt and dust.

From the above data analysis, it can be seen that the air infiltration of plastic windows at level 1 compared to level 4 has increased by 4 times. This means that the energy consumption of air conditioning equipment differs by at least more than 2 times (subtracting the heat transfer coefficient of the walls). Calculating with a 1000W small air conditioning unit, using it a few more hours a day can waste several yuan, and a small bedroom can waste 200 to 300 yuan a year. In the cold northern regions, the indoor and outdoor temperature difference in winter is generally over 30°C (commonly known as: large holes and strong winds), leading to even more serious energy consumption. Looking at the price difference, ordinary single-glass residential windows cost around 150 to 180 yuan per square meter, while hollow white glass engineering windows cost between 220 and 240 yuan per square meter. The patented energy-saving windows are priced at 360 yuan/m², requiring users to spend more than a hundred yuan per square meter, but high-quality energy-saving windows require very little maintenance over thirty years, while inferior windows may require at least 200 to 300 yuan in maintenance costs over decades. Choosing low-priced, non-energy-saving plastic windows is purely a case of losing big for small savings.

In the reality where the energy-saving effect of sliding doors and windows is generally difficult to improve, Huai'an Happiness Door and Window Co., Ltd., a high-tech product manufacturing enterprise in Jiangsu Province, has focused on independently developing "Health Brand" doors and windows, obtaining four national utility model patents: "High-Strength Energy-Saving Plastic Profile Sliding Window Sash" and "Energy-Saving Plastic Sliding Window". As a result, the patented technology used in the overall components of the "Health Brand" sliding window is energy-saving, with tight assembly, and its wind pressure resistance, airtight performance, water tightness, and sound insulation performance are all above level 4, with insulation performance above level 7. This product meets 65% of the technical requirements for building energy saving. Tests show that using this door and window, each air conditioning unit can save 2 kWh of electricity per day. Based on the national average for cooling or heating for 180 days a year, with two units per household, each household can save 720 kWh × 0.6 yuan/kWh in electricity costs per year, amounting to 432 yuan. The quality lifespan of energy-saving windows is about 30 years, allowing each household to save over 12,960 yuan in electricity costs over 30 years.