====== Heat Exchanger ======

G1 has a heat recovery ventilation system. It is the computer fans and pipes attached to the window.

It blows air outside through one set of channels, and sucks air in through channels which are in close contact with those. The contraflows of air exchange heat, so that the air coming in is heated using the energy of the air that is going out. This way, we receive fresh air with minimal heat loss.

It has now been fitted with a controller which is under development. The purpose of it is to balance the airflow in each direction, which gives the greatest heat recovery.

If there was no pressure difference on each side, a controller would not be needed. It is there to compensate for wind, or use of the extractor fan, for example. When operating, fans will be at full power in at least one direction.

The fans may switch off if CO2 levels are low.

===== Monitoring =====

Monitoring may be available on [[https://grafana.ehlab.uk/d/ehcaeIB4z/heat-exchange-ventilator|grafana]].

===== Control =====

There may be an unstable mqtt or http api.

http://heat-exchanger.hacklab/api/regulation

Please put it back to automatic when finished with any manual settings.