Natural ventilation with heat recovery and solar assistance
A complete concept for natural ventilation with heat recovery and solar assistance has been investigated. The concept is based on a coupled liquid heat exchanger circuit, which have the advantage that the location of the fresh air intake and the exhaust may be independent.
The aim of the project is to investigate a new concept for natural ventilation combined with heat recovery. The heat from the exhaust air is transferred to the fresh air by pump assisted heat pipes. In this way the degree of heat recovery may be varied and adjusted to the needs depending on the season of the year. A large driving force is often available during the winter which means that a high degree of heat recovery is possible. During the summer when the driving force in less there is no need for heat recovery. The driving force may during daytime be enhanced by at solar air collector or a solar chimney at the exhaust side of the systems. The new ventilation concept may be utilized in new building, but as the concept doesn't demand for installation of ductwork and because the location of the boiler and the condenser of the heat recovery unit is optional, heat recovery may also be possible in existing buildings with exhaust ventilation
This allows for at larger variety of system designs and further means that the natural driving forces is utilized better. The investigations have shown that it is possible to design the system in such a ways that the necessary airexchange rate may be maintained under nearly all weather conditions. Calculations have shown that it is possible to recover 30-40% of the ventilation losses during most of the heating season. The concepts not only allows for an arbitrary location of the evaporator and the condenser but makes it further possible to design the systems both as central and decentral systems. The system may also be utilized in buildings with traditional exhaust ventilation in order to make heat recovery possibel. The heat exchanger system uses a refrigerant as heat transporting medium. A refrigerant gives a higher heat transfer than water which means that a smaller mass flow rate is necessary loading to the need of only thin tubes. Calculations have proven that even though the heat recovery rate of the concept is lower that in balanced mechanical ventilation systems with heat recovery, the concept still has a lower consumption of primary energy. It is further judged that the concept is economically competitive with traditional mechanical ventilation systems
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| Gilling Byøkologi | ||
| NILAN A/S | ||
| Vejle Kommune |
Contact
P.O. Box 141
DK-2630 Taastrup, Denmark
Østergaard Jensen, Søren (civ.ing.), 43504559, Soren.O.Jensen@dti.dk
Øvr. Partnere: Gilling Byøkologi; Nilan A/S; Vejle Kommune
