Stack Effect in the Two-Story Living Room:
Hypothesis, Methods, Data and Analysis

Hypothesis

As stated earlier on the hypothesis page, we hypothesize that the two-story open living room will exhibit a significant stack effect.

Methods


A section diagram of the living room
showing the location of the temperature sensors used
to test for a stack effect

To test for the stack effect, we placed four sensors at varying heights in the two-story space. We placed the lowest sensor about 1 foot off the ground on the shelf of an end table. We placed the next sensor about 6 feet off the ground, hanging down from the railing on the second floor. We placed the third sensor on that railing, about 12 feet off the floor. We placed the fourth sensor on the top of a bookshelf near the ceiling, about 16 feet off the floor. We expected to find that the relative position of the temperatures from a sensor would correspond with their relative height within the room. In other words, the lowest sensor would read the lowest temperatures. The next highest in elevation would then read the next highest temperature, and so on.

Data and Analysis

Here is a graph that shows two days worth of data from our four sensors.

This graph shows clear evidence of a stack effect in the two-story living room (11 k gif)

These data clearly show a strong stack effect in the living room. The sensors consistently read relative temperatures that correspond to their elevation, the higher sensors reading higher temperatures. The difference in temperatures from the lowest sensor to the highest can be quite significant. At night, there is about a 2 degree difference between top and bottom, but during the day, there develops almost a 10 degree difference at the two extreme elevations.

Conclusions

The open space above the living room creates a significant stack effect. The stack effect may cause the house to use extra energy to heat the space enough so that the lower floor reaches a comfortable temperature.

Comments to author: vitalsigns@
ced.berkeley.edu

All contents copyright (C) 1998. Vital Signs Project. All rights reserved.

Created: 04/23/96
Revised: 09/09/02

http://www-archfp.ced.berkeley.edu/vitalsigns/workup/siegel_house/sgl_stak.html