Pilot project: Proof-of-concept regarding miniature sensor for resistanceless measurement of air velocity
This pilot project introduces a new sensor type for measuring airflows. The sensor is based on Micro Electro-Mechanical System, MEMS, and the sensor is called EFV, Elastic Filament Velocimetry.
Replacing existing measuring crosses in a ventilation system with the new sensor type can lead to a reduction of the energy requirement for ventilation of at least 20% depending on the number of measuring crosses in the system. In addition, improved indoor climate can be achieved, as the EFV sensors make it possible to control the airflows more precisely.
The EFV sensor is developed at Princeton University, New Jersey, USA. The sensor is designed for measuring fluid flow in medical technology, but in this pilot project, the EFV sensor is modified to measure air flows in ventilation ducts and proof-of-concept is demonstrated.
The pilot project is the foundation for a subsequent ph.d.-project and through simulations and laboratory tests, the characteristics of the EFV sensors are identified and correction factors are determined. Hereby the EFV sensors, unlike conventional sensors, can be placed in the duct system independent of bends and dimension changes.
In consultation with Bygningsstyrelsen EFV sensors are installed in a ventilation system in a building at Syddansk Universitet, SDU. The purpose is to investigate the function of the EFV sensors in practice and to demonstrate the expected energy savings.
- The experimental studies in laboratory show that the EFV-sensor is capable of measuring air velocities lower than 0.1 m/s in a pipe with a diameter of 1.14 mm and from 0.4 m/s in a ventilation duct with a diameter of 160 mm. The uncertainty of the measured data is ± 0.025 m/s
- The CFD simulations indicate that a larger through-hole in the sensor can improve the capabilities of the EFV-sensor to measure air velocities in the duct system below 0.4 m/s.
- The results show that the EFV-sensor creates a lower pressure drop compared to a measur-ing cross, indicating that replacing measuring crosses with EFV-sensors can lead to a reduction of the energy use for fan operation.
- The experimental studies show that the EFV-sensor is capable of measuring turbulence intensity, as the response frequency of the sensor can be 100 kHz.
Furthermore, the price for an EFV-sensor is expected to be at least 100-200 times lower than that of UltraLink.
The low price may lead to a significantly wider use of sensors, which can be used in machine learn algorithms for improvement of comfort and reduction of energy use in the next generation ventilation systems
The present pilot project has shown the potential of the EFV-sensor for measuring air veloci-ties in ventilation ducts.
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| Bygningsstyrelsen | ||
| Princeton University |
