Eight Essential Functions of a Fresh-Air System

Air pollution has a complex composition. In addition to the familiar PM2.5, it contains various harmful gases and odors. Vehicle exhaust, for example, contains large amounts of harmful substances, including carbon monoxide, nitrogen oxides, and hydrocarbons. Chemical exhaust may contain carbon dioxide, carbon disulfide, hydrogen sulfide, and many other toxic and harmful gases, all of which can seriously harm our health.

In addition to filtering PM2.5, a fresh-air system should be able to filter harmful gases and odors. A unit equipped with an activated-carbon filter can effectively block various toxic gases and odors in outdoor air, making the air supplied indoors cleaner and safer.

2. Heating Incoming Air in Winter

During a cold winter, directly supplying icy outdoor air would certainly make occupants uncomfortable. Moreover, when the outdoor temperature falls below 0 degrees C, condensation and icing may occur inside the unit and prevent normal operation. Electric auxiliary heating is therefore essential. However, if a fresh-air system offers only two or three fixed heating-power settings, the actual results may still be disappointing, and electricity consumption may also become an issue.

To keep the supply-air temperature comfortable and deliver warm air in winter, consider a fresh-air system with intelligent heating. This type of unit lets users set the outlet-air temperature. It also adjusts its operating power intelligently to the lowest necessary level according to the indoor-outdoor temperature difference, the airflow setting, and the target heating temperature.

3. Noise-Reduction Technology

The acoustic performance of a fresh-air system directly affects the user experience. Many people install these systems in bedrooms to create a more comfortable, quiet, and healthy sleeping environment. This is particularly important for light sleepers, some of whom even find the sound of an air conditioner disturbing. If a fresh-air system lacks effective noise-control technology, it becomes a noise generator rather than a comfort upgrade.

When choosing a unit, pay close attention to its stated noise level. Ideally, a product should provide enough fresh air while remaining silent on its low setting. The Tion 3S fresh-air system, for example, uses a German ultra-quiet EBM motor together with EPP material, acoustic insulation ducting, and sound-insulating sealing rings. Its low-speed noise level is only 19 dB and is effectively inaudible. At high speed, a unit should preferably remain below 50 dB; otherwise, its high-airflow setting may be too loud to use.

4. Electric Air Damper

An electric air damper is another indispensable component. When the unit is switched off, the damper closes automatically to prevent cold outdoor air from entering the room.

5. Internal Insulation Layer

A fresh-air system brings outdoor air indoors. In cold winter weather, that air passes through the unit and can affect its internal components, making an internal insulation layer essential. Many European manufacturers of wall-mounted fresh-air units use large amounts of EPP because it provides excellent thermal insulation, is environmentally friendly and 100% recyclable, and is lightweight enough for this application.

Few fresh-air units sold in China currently make extensive use of EPP. The Tion 3S, however, is built throughout with environmentally friendly EPP, while the Tion Mini also uses a substantial amount of the material.

6. Remote Control or Mobile App

A fresh-air system should also be easy and convenient to operate. With a remote control or mobile app, users can adjust the airflow setting or fresh-air heating temperature at night with a tap or button press, without getting out of bed.

7. Safety System

A fresh-air system with electric auxiliary heating must have a well-designed safety system. Such systems generally heat incoming air with a PTC ceramic semiconductor. Although the PTC material and structure are inherently safe, the unit's design and workmanship remain important. Users must be kept from contacting heating elements; the system should prevent the PTC from overheating, protect the power board, use fire-resistant materials, and keep dust and moisture out of the PTC assembly. These measures help eliminate safety hazards and minimize failures.

8. Controllable Indoor Recirculation

Many users report that fresh-air filters become dirty very quickly when the system operates during severe smog, increasing consumables costs. Some people buy a fresh-air system specifically to combat smog but do not want the cost of doing so to be excessive. An indoor-recirculation mode can reduce consumables costs: when outdoor pollution is especially severe, users can select recirculation or mixed mode to clean indoor air quickly without unnecessarily consuming filter capacity.

Users should be able to control the ratio of outdoor air to return air. On the Tion 3S, for example, fresh-air mode supplies only outdoor air; mixed mode uses a 1:1 ratio of outdoor air to return air; and recirculation mode cleans indoor air so the unit functions as an air purifier.