skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Sensitivity of occupant comfort models to humidity and their effect on cooling energy use

Journal Article · · Building and Environment
ORCiD logo [1]; ORCiD logo [2];  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
+ Show Author Affiliations

Residential building energy consumption in the United States has decreased steadily during the last several decades largely because of advances in building codes as well as voluntary efficiency and labeling programs, which have resulted in the reduction in building sensible loads. Building latent loads have not decreased by the same amount, and field and analytical research studies have concluded that high-efficiency, low-load homes often have elevated indoor humidity levels, possibly leading to occupant discomfort. There are discrepancies in the literature on occupant comfort as it relates to indoor humidity and recommended upper humidity limits. The choice of humidity limit could potentially change results and conclusions on the energy impacts of a new air conditioner or dehumidifier technology, changing ventilation rates, or an improved building envelope. In this study, we use building simulations to explore the impact of humidity control on cooling energy use in efficient residential buildings for different humidity limits. We look at limits based on humidity ratio (or dew point temperature), wet-bulb temperature, relative humidity, and constant slope lines based on the popular comfort models of both Fanger and Gagge. We quantify the additional energy use required to control humidity below these limits. We look at the sensitivity of the results to different temperature and humidity set points, occupant internal gains, moisture buffering levels, evaporator airflow rates, and dehumidifier energy factors. High-efficiency home predicted energy savings are more sensitive to the assumed humidity limit and cooling and dehumidification set points than the other parameters investigated in this paper.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Building Technologies Office
Grant/Contract Number:
AC05-00OR22725; AC36-08GO28308
OSTI ID:
1546543
Alternate ID(s):
OSTI ID: 1544530; OSTI ID: 1693480
Report Number(s):
NREL/JA-5500-73169
Journal Information:
Building and Environment, Vol. 162, Issue C; ISSN 0360-1323
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

Figures / Tables (17)

Figure 1(p. 4)figure Figure 1
Figure 2(p. 7)figure Figure 2
Figure 3(p. 8)figure Figure 3
Figure 4(p. 10)figure Figure 4
Figure 5(p. 11)figure Figure 5
Table 1(p. 12)table Table 1
Figure 6(p. 13)figure Figure 6
Table 2(p. 13)table Table 2
Figure 7(p. 14)figure Figure 7
Table 3(p. 15)table Table 3
Figure 8(p. 16)figure Figure 8
Figure 9(p. 17)figure Figure 9
Figure 10(p. 20)figure Figure 10
Figure 11(p. 22)figure Figure 11
Figure 12(p. 24)figure Figure 12
Figure 13(p. 26)figure Figure 13
Figure 14(p. 28)figure Figure 14

Similar Records

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
Comfort models
Occupant comfort
Indoor humidity
Cooling energy
Low load
Moisture buffering
Effective moisture penetration depth
Humidity
Building energy modeling
Moisture
comfort models
occupant comfort
indoor humidity
cooling energy
low load
moisture buffering
effective moisture penetration depth
humidity
building energy modeling
moisture