Why Did Plywood Surface Temperature Initially Lag in Heating Experiment?

[TSN79]

In an experiment I heated a room and logged the temp change as it went up. One of the walls in the room is made of plywood. I also logged the temp on this surface (on the heated side). When I looked at the graph after the experiment I noticed that as the air temp of the room went up, the surface temp of the plywood was reluctant to follow the change. It only increased slightly for a while before suddenly skyrocketing about ten degrees within a few minutes.

When I did the whole thing again the next day, the same thing didn't happen. Now the surface temp rose evenly with the room temp.

I'm confused as to this "reluctantness" in the first experiment. Any explanations?

 

[FredGarvin]

There's got to be some reason for it. Is this room in a controlled environment or is it in a house somewhere? It could be an instrumentation error. How did you instrument the wall surface? A sudden increase in a material like plywood is pretty unnatural in a normal setting unless there is a fire or something along those lines.

Also, I would look for heating ducts, etc...running through the wall. Anything to transfer heat away from the surface.

Can you go into more detail about the wall's construction?

 

[ravenprp]

There could be a few possible explanations for this reluctance in the first experiment. One possibility is that the plywood wall may have had a higher thermal inertia than the rest of the room, meaning that it takes longer for it to heat up and cool down. This could explain the initial slow increase in surface temperature before suddenly skyrocketing. Another possibility is that there may have been some external factors, such as air flow or insulation, that affected the rate at which the plywood absorbed heat from the room. It's also possible that there was some error in measurement or data collection in the first experiment, leading to an inaccurate representation of the surface temperature. Without further information or repeated experiments, it's difficult to determine the exact cause of this reluctance. However, the fact that the second experiment did not show the same pattern suggests that it may have been a one-time occurrence or an anomaly. It's always important to carefully analyze and interpret data to ensure accurate and reliable results in experiments.