# Indoor environmental quality in schools: NOTECH solution vs. standard solution

## TL;DR

This study compares a new low-cost ventilation system (NOTECH) with traditional mechanical ventilation in a Danish school, finding similar indoor air quality but much lower costs and carbon footprint for NOTECH.

## Contribution

The study introduces and validates a cost-effective and environmentally friendly ventilation solution for schools.

## Key findings

- Both ventilation systems maintained acceptable indoor environmental quality and CO2 levels below 1000 ppm.
- The NOTECH system had 35% lower overall costs compared to the mechanical ventilation system.
- NOTECH reduced the embedded CO2 footprint of building materials by 95%.

## Abstract

Background

In many Danish schools, the indoor environmental quality (IEQ) is challenging and studies document a poor IEQ in a majority of existing schools. Municipalities cannot afford comprehensive renovations and expensive mechanical ventilation solutions, hence public schools often suffer from poor indoor environment conditions. This study tests a new façade based, demand-controlled ventilation solution called NOTECH in the renovation of school. The study tests NOTECH vs. existing mechanical ventilation solution, comparing performance of both solutions at Skovbrynet Skole in Denmark.

Methods

The project implements and investigates the effect of the NOTECH solution in a primary school classroom, comparing it to a similar classroom with conventional, mechanical ventilation. Methodically, indoor environmental quality and energy performance is monitored in the two identical classrooms during one school year 2018 - 2019.

Results

The results show that both systems keep the conditions within acceptable limits and CO
2 levels below 1000 ppm, which is the requirement according to the Danish Building Regulations. In terms of costs, the NOTECH system has a lower overall cost than the mechanical ventilation system, with total estimated costs for installation, heating, electricity and maintenance amounting to approximately 35% of the mechanical system’s costs. Finally, the results show that the NOTECH solution has a smaller embedded CO
2 footprint for building materials, reducing the estimated carbon load by 95% compared to the mechanical ventilation solution.

Conclusions

The performance of the two systems roughly is the same in relation to the indoor environmental quality, temperature, CO
2 levels, humidity and noise level. Costs for implementation, energy consumption for heating and CO
2 footprint for building materials however, are significantly lower for the NOTECH solution, compared to the mechanical solution.