This function calculates the Equilibrium Moisture Content (EMC) of wood based on relative humidity and temperature.
Details
Equilibrium Moisture Content (EMC) is the moisture content at which a material, such as wood or other hygroscopic substanceshas reached an equilibrium with its environment and is no longer gaining or losing moisture under specific temperature and relative humidity.
A safe EMC range for wood is typically between 6% and 20%. This range helps to prevent issues such as warping, cracking, and mold growth, which can occur if the moisture content falls below or exceeds these levels.
References
Simpson, W. T. (1998). Equilibrium moisture content of wood in outdoor locations in the United States and worldwide. Res. Note FPL-RN-0268. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory.
Hailwood, A. J., and Horrobin, S. (1946). Absorption of water by polymers: Analysis in terms of a simple model. Transactions of the Faraday Society 42, B084-B092. DOI:10.1039/TF946420B084
Examples
# Equilibrium moisture content for wood at 20°C and 50% relative humidity (RH)
calcEMC_wood(20, 50)
#> [1] 9.271141
# mydata file
filepath <- data_file_path("mydata.xlsx")
mydata <- readxl::read_excel(filepath, sheet = "mydata", n_max = 5)
mydata |> dplyr::mutate(EMC = calcEMC_wood(Temp, RH))
#> # A tibble: 5 × 6
#> Site Sensor Date Temp RH EMC
#> <chr> <chr> <dttm> <dbl> <dbl> <dbl>
#> 1 London Room 1 2024-01-01 00:00:00 21.8 36.8 7.20
#> 2 London Room 1 2024-01-01 00:15:00 21.8 36.7 7.19
#> 3 London Room 1 2024-01-01 00:29:59 21.8 36.6 7.17
#> 4 London Room 1 2024-01-01 00:44:59 21.7 36.6 7.17
#> 5 London Room 1 2024-01-01 00:59:59 21.7 36.5 7.16