Application: HVAC

Five data loggers were used to investigate the interactions of a wood stove with the building it is in: 3- Thermocouple, 1- CO2/RH/Temperature/Barometric and 1- Low Pressure logger.

Thermocouple temperatures were recorded in the firebox, the hot air output to the room, and exhaust temperature at the top of the chimney. CO2/RH/Temperature/Barometric pressure was measured around the wood stove. Building pressurization was measured in the same room as the wood stove relative to outdoor pressure. Graphs were visible in realtime as the tests proceeded, with all five loggers shown on the computer screen at all times.

Although most of the characteristics around the wood stove were quite normal, the extreme temperature oscillation of the firebox required correction. Investigation around the input air damper showed the bi-metal temperature control spring to have poor thermal coupling to the firebox. Shrouding and insulating the bi-metal spring to improve thermal coupling solved the problem, as shown below in a before & after graph of firebox temperature. The ‘before’ temperature line is taken directly from the graph above, and the ‘after’ graph line is from a subsequent test of the firebox using one Thermocouple logger only.