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GITBOOK-42: change request with no subject merged in GitBook
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FedericoTartarini authored and gitbook-bot committed Oct 12, 2024
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4 changes: 3 additions & 1 deletion docs/documentation/ashrae-55.md
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Expand Up @@ -27,7 +27,9 @@ At the top of the user interface, you can choose between the two methods allowed

For more information about the PMV model visit [this page](pmv.md), below a video explaining how to calculate PMV and PPD using the CBE thermal comfort tool.

{% embed url="https://youtu.be/5WkH2SN664k" %}
{% embed url="https://www.youtube.com/watch?v=yXhqkBSe9gQ" %}



### Adaptive method

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17 changes: 10 additions & 7 deletions docs/documentation/en.md
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Expand Up @@ -13,20 +13,24 @@ This guide aims to explain the main features of the tool, and demonstrate how be
The tool has three main parts:

* **Left-hand side**: This section is the user interface. It contains the input fields containing values that drive the comfort calculations and visualizations. To change these input values, you can type directly in the boxes or click on the up and down arrows. There are also several other buttons, their functionality is explained in detail below.
* **Top-right**: This section contains the results of the calculations. The raw output of the comfort model calculations \(such as PMV, PPD, etc. for the PMV method\) as well as compliance information.
* **Top-right**: This section contains the results of the calculations. The raw output of the comfort model calculations (such as PMV, PPD, etc. for the PMV method) as well as compliance information.
* **Bottom-right**: This section contains a visualization of the thermal comfort conditions in the input. There are currently three types of charts visualizing the thermal comfort region, as follows:
* Psychrometric \(plotted using either the dry-bulb air temperature or the operative temperature\)
* Psychrometric (plotted using either the dry-bulb air temperature or the operative temperature)
* Relative humidity vs. dry-bulb air temperature.
* Operative indoor air temperature vs. prevailing mean outdoor temperature \(Adaptive comfort region\).
* Operative indoor air temperature vs. prevailing mean outdoor temperature (Adaptive comfort region).

## Comfort models

At the top of the user interface you can choose between the two methods allowed by the standards, which are the PMV/PPD method and the Adaptive method. For more information about the comfort models, you can follow the link to Wikipedia by clicking on 'select method'.

### Predicted Mean Vote \(PMV\)
### Predicted Mean Vote (PMV)

For more information about the PMV model visit [this page](pmv.md).

{% embed url="https://youtu.be/pUnYxyt0wFQ" %}



### Adaptive method

By choosing the Adaptive method at the very top of the user interface, the chart changes and the input variables include air temperature, mean radiant temperature and outdoor running mean temperature. This is because the personal factors and humidity are not significant in this method since adaptation is considered, and the only variable is the outdoor temperature. See above for explanation of the first two variables, air and mean radiant temperature.
Expand All @@ -47,7 +51,7 @@ At the bottom of the input section of the tool, you can find more clickable butt

Clicking on this button, a new window pops up, letting you type the following inputs: air temperature, air speed, globe temperature, globe diameter, globe emissivity, to calculate the correspondent Mean Radiant Temperature, that can be set as the current value by clicking the 'set' button. This feature allows you to have a more precise evaluation of the MRT by taking measurements with a globe thermometer. The button is disabled when the operative temperature is used.

{% embed url="https://youtu.be/ReSqx9TJgSI" caption="" %}
{% embed url="https://youtu.be/ReSqx9TJgSI" %}

### Set pressure

Expand All @@ -59,9 +63,8 @@ This button sets some default values for all the input variables, to restart the

### SI/IP

Click on this button to switch between the International System of Units \(SI\) and the Inch-Pound system.
Click on this button to switch between the International System of Units (SI) and the Inch-Pound system.

### Local thermal discomfort

Even though the comfort model based on PMV/PPD describes compliance to thermal comfort for the body as a whole, thermal dissatisfaction may also occur just for a particular part of the body due to local sources of unwanted heating, cooling or air movement. This feature allows you to verify the compliance of the space to the Standard as regards local thermal discomfort. By feeding the tool with measurements of air temperature in particular zones surrounding the occupant, you can see whether the discomfort effect in the space is likely to exceed the ISO 7730 acceptability limits. Change the values in the input boxes according to your measurements. A checkmark will appear next to each section, while a general compliance message will be shown at the bottom of the dialog. Remember that to comply with the Standard all the sections must respect the limits.

15 changes: 9 additions & 6 deletions docs/documentation/pmv.md
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# PMV Model

{% embed url="https://www.youtube.com/watch?v=NVdmuEdDUNM" %}



Six primary factors affect thermal comfort. These include environmental conditions such as air temperature, and personal factors such as metabolic rate.

## Environmental factors
Expand All @@ -8,7 +12,7 @@ Six primary factors affect thermal comfort. These include environmental conditio

By modifying this value, you will notice the output in the upper-right region changing, as well as the red dot on the chart moving. Depending on which specification of humidity is being used, the red dot may follow the lines of constant relative humidity, or move horizontally. This value does not affect the comfort zone itself, since the zone represents a range of air temperature and humidity values. Next to the air temperature box, you can click on the 'use operative temperature' button. When this option is selected, it will be assumed that the air temperature and mean radiant temperature are equal to the value in the operative temperature input field.

### Mean Radiant Temperature \(MRT\)
### Mean Radiant Temperature (MRT)

MRT represents the mean of the radiant temperatures of the enclosing surfaces of a space, which is determined by the emissivity and the temperature of the surfaces. This value affects the location of the comfort zone, since it may affect the range of acceptable air temperatures. For example, higher radiant temperatures allow the occupant to feel comfortable at lower air temperatures, or vice versa. Thus, an increase in MRT shifts the comfort zone to the left side of the charts.

Expand All @@ -18,7 +22,7 @@ This is the rate of spatial change of air in a space, which is used to calculate

#### Self-generated Air Speed

The body movement affects the air speed surrounding the human body. Consequently, the sum of the average air speed and the self-generated air speed shall be used as input in the PMV model. In accordance with the ASHRAE 55 and the ISO 7730, if the metabolic rate is higher than 1 met, the self-generated air speed is calculated using the following equation: V\_sg = V + 0.3 \(MET - 1\). Where V is the "Average air speed" and MET is the "Metabolic rate". The CBE comfort tool automatically calculates the self-generated air speed for you in the background and sums it to the average air speed you entered in the tool.
The body movement affects the air speed surrounding the human body. Consequently, the sum of the average air speed and the self-generated air speed shall be used as input in the PMV model. In accordance with the ASHRAE 55 and the ISO 7730, if the metabolic rate is higher than 1 met, the self-generated air speed is calculated using the following equation: V\_sg = V + 0.3 (MET - 1). Where V is the "Average air speed" and MET is the "Metabolic rate". The CBE comfort tool automatically calculates the self-generated air speed for you in the background and sums it to the average air speed you entered in the tool.

### Relative Humidity

Expand All @@ -28,15 +32,14 @@ Relative Humidity is the ratio of the partial pressure of the water vapor in the

### Metabolic Rate

Metabolic rate is the rate of energy production of the body, which varies for different activities. A list of common activities and correspondent metabolic rate in met units is available next to the input box. You can either chose one value from the list or type a different and more precise one directly, as preferred. Increasing the metabolic activity means moving the comfort zone significantly towards lower temperatures and vice versa, since higher activities make the body produce more heat and thus be more comfortable in colder environments. Elevated metabolic rate can also result in decreased effective clothing value and increased relative air speed \(as air is pumped through clothing\).
Metabolic rate is the rate of energy production of the body, which varies for different activities. A list of common activities and correspondent metabolic rate in met units is available next to the input box. You can either chose one value from the list or type a different and more precise one directly, as preferred. Increasing the metabolic activity means moving the comfort zone significantly towards lower temperatures and vice versa, since higher activities make the body produce more heat and thus be more comfortable in colder environments. Elevated metabolic rate can also result in decreased effective clothing value and increased relative air speed (as air is pumped through clothing).

### Clothing level

Clothing is probably the most important variable in terms of adaptation to a thermal environment, and this means that acting on the clothing level may be very effective to reduce energy consumption. This tool allows you to select clo values for common clothing ensembles by the list on the right of the input box, or also to create a custom ensemble by choosing every garment that composes it, by clicking on the button just beneath. This meets the methods provided by the Standard to evaluate the clothing insulation, as you can see in more depth by clicking on the Wikipedia link. It's important not to forget the clo value provided by the chair, that can be found in the list of garments. Once the ensemble has been created, the clo value can be set to the input field.

#### Dynamic clothing insulation

The body movement affects the insulation characteristics of the clothing and the adjacent air layer. Consequently, the dynamic clothing insulation \(I\_clo\_dynamic\) shall be used as input to calculate the thermal comfort indices.

* ASHRAE 55 Standard: defines that the following equation shall be used to calculate the dynamic clothing insulation. I\_clo\_dynamic = CLO \(0.6 + 0.4 / MET\). Where CLO is the "Clothing level" and MET is the "Metabolic rate" you entered as input in the CBE thermal comfort tool, respectively. The CBE comfort tool automatically calculates the dynamic clothing insulation for you in the background.
The body movement affects the insulation characteristics of the clothing and the adjacent air layer. Consequently, the dynamic clothing insulation (I\_clo\_dynamic) shall be used as input to calculate the thermal comfort indices.

* ASHRAE 55 Standard: defines that the following equation shall be used to calculate the dynamic clothing insulation. I\_clo\_dynamic = CLO (0.6 + 0.4 / MET). Where CLO is the "Clothing level" and MET is the "Metabolic rate" you entered as input in the CBE thermal comfort tool, respectively. The CBE comfort tool automatically calculates the dynamic clothing insulation for you in the background.

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