s <- suppressPackageStartupMessages
library(data.table)
library(lubridate)
library(knitr)
library(dygraphs)

1 Introduction

This R Notebook utilizes the javascript functions from the CBE Comfort Tool, freely available on the website’s Github in order to estimate the thermal comfort of the students of FROG UHM.

2 Readings

The readings are a sample data from the frog-uhm project provided by Eileen Peppard to test the tool.

readings <- fread("~/Desktop/aug-24-comfort-sample.csv")

2.1 Used Variables

Of the provided data, the following variables were used:

  • Air Temperature
  • Mean Radiant Temperature
  • Relative Air Velocity
  • Relative Humidity

In addition, the following artificially created variables were used:

  • Metabolic Rate = 1.1
  • Clothing Level = 0.5
  • External Work = 0 (According to the CBE Comfort Tool Documentation)
AddOtherVariableAssumptions <- function(building){
  building$met <- 1.1
  building$clo <- 0.5
  building$wme <- 0
  return(building)
}
readings <- readings[,.(building,datetime,ta=temperature_air_f,tr=temperature_mrt_f,vel=air_flow_fpm,rh=humidity_percent)]

readings <- AddOtherVariableAssumptions(readings)

3 Conversions

For the CBE Comfort Tool, the following units must be respected for the variables:

And were converted from the sample data to meet the expected units.

#Convert F to C
readings$ta <- (readings$ta - 32)*(5/9)
readings$tr <- (readings$tr - 32)*(5/9)

# Convert fpm to m/s
readings$vel <- 0.00508 * readings$vel

4 Split Frog Buildings

We calculate the PMV for the frog buildings separately over time.

frogs1 <- readings[building=='frog-1',.(ta,tr,vel,rh,met,clo,wme)]
frogs2 <- readings[building=='frog-2',.(ta,tr,vel,rh,met,clo,wme)]

5 Elevated Air Speed PMV Model

This notebook uses the javascript function from the CBE Comfort Tool by passing the sample data after preparation as input, and then retrieving the output of the function which contains the PMV and PPD.

6 Merge Results with Timestamps and Readings

After the model results is output, the data is combined with the original readings for comparison.

frogs1_elevated_air_pmv <- cbind(readings[building=='frog-1'],frogs1_elevated_air_pmv)
frogs2_elevated_air_pmv <- cbind(readings[building=='frog-2'],frogs2_elevated_air_pmv)

7 PMV Results

In addition to PMV and PPD, the following columns are also output in the table (not shown below):

The first 3 columns relate to the Elevated Airspeed adjustmenet to the PMV model, which can’t handle high air speeds in the original proposal by Fanger.

7.1 Frogs 1

First few rows of the table for Frogs 1.

kable(head(frogs1_elevated_air_pmv))
building datetime ta tr vel rh met clo wme pmv ppd set ta_adj tr_adj cooling_effect
frog-1 8/24/2017 07:00:00 28.10000 27.66667 0.0000 58.13 1.1 0.5 0 -1.019385 26.94295 28.35231 28.10000 27.66670 0.0000000
frog-1 8/24/2017 07:05:00 27.92778 27.61111 0.0000 58.21 1.1 0.5 0 -1.082323 29.71119 28.24999 27.92780 27.61110 0.0000000
frog-1 8/24/2017 07:10:00 27.80000 27.55556 0.1778 59.04 1.1 0.5 0 -1.361422 43.46731 27.96895 27.58704 27.34264 0.2129565
frog-1 8/24/2017 07:15:00 27.86111 27.61111 0.1778 57.30 1.1 0.5 0 -1.360287 43.40757 27.99993 27.64781 27.39781 0.2132927
frog-1 8/24/2017 07:20:00 27.83889 27.61111 0.1778 57.03 1.1 0.5 0 -1.372148 44.03333 27.98552 27.62443 27.39663 0.2144689
frog-1 8/24/2017 07:25:00 27.86111 27.66667 0.1778 56.99 1.1 0.5 0 -1.352435 42.99468 28.02493 27.64630 27.45190 0.2148009 
dygraph(frogs1_elevated_air_pmv[,.(mdy_hms(datetime),pmv)], main = "Frogs 1 PMV Value") %>% dyRangeSelector()

7.2 Frogs 2

First few rows of the table for Frogs 2.

kable(head(frogs2_elevated_air_pmv))
building datetime ta tr vel rh met clo wme pmv ppd set ta_adj tr_adj cooling_effect
frog-2 8/24/2017 07:00:00 29.17222 28.44444 0.00508 56.54 1.1 0.5 0 -0.5402296 11.10754 29.21211 29.1722 28.4444 0
frog-2 8/24/2017 07:05:00 29.26111 28.44444 0.00508 55.76 1.1 0.5 0 -0.5301976 10.88092 29.23702 29.2611 28.4444 0
frog-2 8/24/2017 07:10:00 29.26111 28.44444 0.00508 56.42 1.1 0.5 0 -0.5174139 10.59844 29.24754 29.2611 28.4444 0
frog-2 8/24/2017 07:15:00 29.27778 28.44444 0.00508 55.28 1.1 0.5 0 -0.5348055 10.98447 29.23636 29.2778 28.4444 0
frog-2 8/24/2017 07:20:00 29.27778 28.44444 0.00508 56.46 1.1 0.5 0 -0.5119278 10.47938 29.25520 29.2778 28.4444 0
frog-2 8/24/2017 07:25:00 29.25000 28.44444 0.00508 56.21 1.1 0.5 0 -0.5246116 10.75661 29.23954 29.2500 28.4444 0 
dygraph(frogs2_elevated_air_pmv[,.(mdy_hms(datetime),pmv)], main = "Frogs 2 PMV Value") %>% dyRangeSelector()