What does passive ultra-low energy building mean?

Passive ultra-low energy consumption residential building, referred to as passive residence for short, refers to a residential building that adapts to the climate characteristics and natural conditions, adopts the envelope structure with better thermal insulation and air tightness, adopts efficient new air heat recovery technology, minimizes the demand for heating and cooling, rationally utilizes renewable energy, and provides a more comfortable indoor environment with less energy consumption.

Characteristics of passive ultra-low energy consumption residential buildings

1. Extra-thick external insulation

The insulation thickness of the external wall of ordinary buildings is about 80mm, and that of passive ultra-low energy-consumption houses is generally above 200mm, which is equivalent to putting down jackets on passive ultra-low energy-consumption houses and reducing indoor cold and heat losses.

2. Insulation of partition wall

Different from ordinary buildings with only external wall insulation, all partitions and floors of passive ultra-low energy-consumption houses are provided with insulation layers, which is equivalent to putting on thermal underwear in the room, effectively preventing heat transfer between households and avoiding indoor temperature fluctuation caused by friction between adjacent users.

3. Energy-saving exterior doors and windows

Passive ultra-low energy consumption residence adopts passive thermal insulation sealed door with high thermal insulation and energy saving, which improves the thermal insulation performance by 2-3 times compared with the traditional external door, ensures that the temperature difference between the surface and the room does not exceed 3℃, and maintains a comfortable indoor temperature environment.

4. High air tightness

The external doors and windows of passive ultra-low energy consumption residential buildings have high thermal insulation performance and good air tightness; In addition, the top of the door window frame and partition wall are provided with waterproof and vapor-proof films. It is equivalent to wearing a waterproof and windproof coat for the room. When the indoor and outdoor pressure difference is 50Pa, due to the infiltration of doors and windows, the ventilation times of ordinary buildings are about 5~7 times/h; In passive house, the air exchange frequency can be less than 0.6 times /h, and the air tightness effect is better 10 times, which effectively prevents cold air in winter and hot air in summer from penetrating into the room through gaps, causing indoor temperature and humidity fluctuations.

Avoid hot bridge

General thermal bridge refers to structural columns, ring beams, door and window frames, etc. that connect indoor and outdoor. Because its thermal conductivity is better than that of the external wall with thermal insulation, it leads to large heat loss in winter and low internal surface temperature, resulting in thermal bridge effect, which leads to condensation, mildew and even dripping on the internal wall of the house.

In order to prevent thermal bridge in ordinary buildings, structural insulation of 0.3~0.5m is usually set in the cantilever part of envelope structures such as external walls and roofs, which cannot completely avoid thermal bridge. However, passive ultra-low energy consumption residence requires all structures to be equipped with insulation layers, which are continuous and uninterrupted. As large as balconies and parapets, as small as threading pipes and fixing anchor bolts, heat preservation treatment should be done to completely eliminate the occurrence of thermal bridges.

6. Fresh air heat recovery

In order to ensure the fresh indoor air with good sealing effect, each household of passive ultra-low energy consumption residence is equipped with fresh air ventilator and CO2 content detection device to ensure the indoor CO2 content is 1 000 ppm. The fresh air equipment has a built-in PM2.5 purification device to ensure the cleanliness of indoor air. At the same time, fresh air ventilator is also equipped with outdoor air conditioners, which can provide indoor heat or cooling capacity by heating or refrigerating air, so as to keep the indoor temperature constant.

7. Continuous indoor quiet

The high sealing performance of doors and windows can effectively isolate outdoor noise, and the insulation layer of the floor and partition wall between residents can not only play the role of thermal insulation, but also effectively play the role of sound insulation, reduce the sound transmission between residents, and stay away from the noise disturbance of pets and naughty children upstairs.

In addition, the fresh air equipment is hung in the ceiling of the kitchen or storage room, and the air supply outlet is only set in the living room area of the bedroom, so that the noise of indoor air conditioning equipment is avoided and the quiet and comfortable indoor environment is ensured.