®01
Carbon dioxide keeps climbing
In crowded classrooms and meeting rooms, CO₂ quickly passes 1500 ppm, bringing dizziness, drowsiness and loss of concentration.
Fresh Air Purification
Clean air with every breath
Keep the windows closed and still bring in a steady supply of filtered fresh air, while carbon dioxide, formaldehyde, odours, moisture, cooking fumes, dust and some bacterial/viral aerosols are drawn out in an orderly way. Cal Inc. deliversSurvey · Design · Equipment · Smart Control · Installation · Commissioning · Testing · Maintenancea one-stop fresh air purification service.
What happens without fresh air
With windows shut, pollutants only come in — never out — and keep building up.
02
Long-term release of formaldehyde and TVOC
Panels and adhesives can release harmful gases for years; occasional window opening cannot keep diluting them.
03
No escape on smoggy days
When outdoor PM2.5 is high you can only shut the windows, yet particles indoors keep coming from movement, doors opening and clothing.
04
Humidity out of control · mould and dust mites
During the humid spring and plum rain seasons indoor humidity stays high, corners grow mould, fabrics turn damp, and dust mites and mould follow.
05
Higher risk of cross-infection
In still air, droplets and aerosols linger longer — one cold easily spreads through a family or a whole class.
06
Odours and stale, stuffy air
Tobacco smoke, cooking fumes, bathroom odours and renovation smells circulate in a sealed space and are hard to clear.
Opening windows depends on weather, noise and security, and is hard to sustain. That is exactly why a fresh air system exists。
Why Choose Us
Fresh air is not a box you buy — it is choosing a team that owns the design, the installation and the long-term maintenance.
01
Accountable for results only
We do not make equipment and we are not tied to a brand — we pick what fits. Multiple brands compared against your layout, needs and budget; design, installation and after-sales under one roof, accountable for the end result.
15000+ m² partner production base
02
One-stop, full-chain delivery
Survey, design, equipment, smart control, installation, commissioning, testing and maintenance handled by one team, with clear lines of responsibility.
8 stages, fully in-house
03
Campus-grade project experience
From campus fresh air at a school affiliated with the Chinese Academy of Sciences to homes, hospitals, offices, five-star hotels, libraries and villas.
10000+ students and teachers served
04
Nationwide service network
Local service centres nationwide: repairs answered immediately, plans with deadlines, spare parts and consumables in stock — distance never delays a job.
15-minute response
05
Long-term commitment and maintenance
Fresh air systems run for years; the real difference shows after handover — scheduled follow-ups, filter change reminders and lifecycle support.
5 years of free monitoring
06
Qualifications and industry recognition
A Grade-A indoor purification contractor with multiple invention patents, named a national outstanding indoor and in-vehicle environment service provider.
2014 — founded in Shanghai
Eight fresh air equipment lines
Units matched by space volume, ventilation method and humidity conditions — from a single room to mid-size public buildings.
Fresh Air Dehumidifier
Fresh Air Dehumidifier
Brings in fresh air while removing moisture, keeping rooms dry through humid seasons — ideal for basements and damp regions.
Smart Multi-Filter Fresh Air Unit
Smart Multi-Filter Unit
Multiple filter stages plus app control: check air quality live and adjust airflow as needed.
Single-Flow Fresh Air Unit
Single-Flow Unit
A single duct brings in fresh air while slight positive pressure pushes stale air out; simple and cost-friendly, suited to single rooms and retrofits.
Dual-Flow Fresh Air Unit
Dual-Flow Unit
Separate supply and exhaust paths keep airflow balanced, combining ventilation efficiency with pressure control.
Quad-Purification Fresh Air Unit
Quad-Purification Unit
Pre-filter, activated carbon and micro-electrostatic stages stack up to 99% PM2.5 filtration for heavy pollution days.
Wall-Mounted Heat Recovery Unit
Wall-Mount ERV
Wall mounting saves ceiling space, and the heat recovery core cuts the heating and cooling loss of ventilation.
Mid-Size Commercial ERV
Commercial ERV
A central fresh air unit for offices, retail and mid-size public buildings, with zoned distribution and central control.
Ceiling Heat Recovery Unit
Ceiling ERV
Hidden in the ceiling, with full heat exchange recovering both temperature and humidity — the workhorse for campus and residential projects.
Multi-stage filtration, layer by layer
From coarse particles to gaseous pollutants, treated stage by stage, with air resistance and noise kept in check. After multi-stage purification, indoor CO₂ can stay below 800 ppm and PM2.5 below 35 μg/m³.
-
01
Pre-filtration
A composite flexible frame seals better and slides smoothly, catching dust, debris, hair and other coarse particles.
-
02
Activated Carbon
A high iodine-value carbon layer adsorbs formaldehyde, benzene series compounds, ammonia, TVOC and other harmful gases.
-
03
Micro-Electrostatic
Up to 99% PM2.5 efficiency with low resistance and no ozone; the module is washable and reusable.
Anatomy · what is inside a fresh air unit
Take the quad-purification model: a fan, heat exchange core, multi-stage filters and a condensate drain work together, and the service hatch lets you pull out filters and core without dismantling the unit.
Duct design decides the real result
The same unit performs very differently depending on duct routing and supply/return layout. We draw to your floor plan and ceiling height, and balance airflow duct by duct.
PE duct · ceiling supply & return
Flexible PE round duct with low bend resistance and free routing — good for apartments and finished interiors.
PVC duct · ceiling supply & return
Rigid PVC delivers stable airflow distribution across large areas and multiple rooms.
Floor supply · ceiling return
Floor-level supply sits closer to the breathing zone, suited to double-height spaces and homes with underfloor heating.
Fresh air dehumidifier ducting
Combined supply and dehumidification ducting for basements, storerooms and damp areas.
Non-standard conditions? We customise
Factories, warehouses and special process spaces rarely have an off-the-shelf answer. Equipment and ducting can be built to your temperature, humidity, corrosion and explosion-proof requirements.
Where It Fits
Starting with the people and places most sensitive to air, fresh air purification is close to a necessity.
A School Affiliated with the Chinese Academy of Sciences
Six campuses over 55 mu (about 3.7 hectares), roughly 40,000 m² of buildings, 65 classes and 4,500 students. High occupancy and long hours with windows shut — a textbook campus fresh air scenario.
6
campuses
55mu
Site area
40,000m²
Floor area
65
classes
4500
students
Equipment: ceiling-mounted campus fresh air system
More case studies →
Service Guarantees and After-Sales
Fresh air systems run for years; the real difference shows after handover.
5
Years of Free Monitoring
5-Year Monitoring
Five years of free air quality monitoring after handover, with data you can look up and trends you can compare.
15
Minute Response
15-Min Response
Repairs answered immediately, with a response within 15 minutes and 100% immediate fault response.
24
Hour Solution
24-Hour Solution
A solution within 24 hours, with 100% committed on-site response.
100
% Regular Follow-Up
Regular Visit
Scheduled follow-ups and filter change reminders; proactive maintenance throughout the service life.
Nationwide
Local Service Centres
Nationwide Service
Local service centres nationwide, with lifecycle support across the whole service life of the product.
After-sales hotline 158 2163 9968
A fresh air plan built around your space
Book a free on-site survey and our engineers will produce airflow calculations and a duct design.
Book a Free Survey