apache weather & site editor aplocate user guide · apache weather & site editor aplocate...

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Apache Weather & Site Editor APlocate User Guide

<Virtual Environment> 6.0

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Contents 1. Introduction ................................................................................................................ 3

2. Location & Site Data .................................................................................................. 4 2.1. Location and Weather Data Wizard ....................................................................................... 5 2.2. Location Data ......................................................................................................................... 5 2.3. Location Data: Latitude .......................................................................................................... 5 2.4. Location Data: Altitude ........................................................................................................... 5 2.5. Location data: Longitude ........................................................................................................ 5 2.6. Daylight Saving Time: Time Adjustment ................................................................................ 6 2.7. Daylight Saving Time: Daylight Saving Period ...................................................................... 6 2.8. Daylight Saving Time: Adjustment for Other Months ............................................................. 6 2.9. Site Data: Ground Reflectance .............................................................................................. 6 2.10. Site Data: Terrain Type .......................................................................................................... 7 2.11. Site Data: Wind Exposure (CIBSE Heating Loads) ............................................................... 7

3. Design Weather Data ................................................................................................. 9 3.1. Design Weather Data Source and Statistics .......................................................................... 9 3.2. Heating Loads Weather Data: Outdoor Winter Design Temperature .................................. 10 3.3. Cooling Loads Weather Data ............................................................................................... 10 3.4. Cooling Loads Weather data: Editing Weather Globally ..................................................... 11 3.5. Cooling Loads Weather Data: Editing Weather Individually ................................................ 12 3.6. Cooling Loads Weather Data: Hourly Temperature Variation ............................................. 13

4. Simulation Weather Data ......................................................................................... 14 4.1. ApacheSim ........................................................................................................................... 14 4.2. UK Building Regulations Part L ............................................................................................ 15

5. Weather Selection Wizard ....................................................................................... 16 5.1. Location and Weather Data Wizard ..................................................................................... 16 5.2. Location and Weather Data Wizard: Source of Design Weather ........................................ 18

5.2.1. Source of Design Weather: ASHRAE Database ......................................................... 19 5.2.2. Source of Design Weather: Custom Database ........................................................... 22 5.2.3. Source of Design Weather: Old Format Apache APL File .......................................... 23 5.2.4. Source of Design Weather: User Input ....................................................................... 25

5.3. Location and Weather Data Wizard: Simulation Weather File ............................................ 25 6. SunPath ..................................................................................................................... 27

6.1. Purpose of the SunPath Program ........................................................................................ 27 7. Menu Items ............................................................................................................... 28

7.1. File Menu: ............................................................................................................................ 28 7.2. Options Menu: ...................................................................................................................... 28 7.3. Help Menu: ........................................................................................................................... 28 7.4. Toolbar Buttons: ................................................................................................................... 28

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1. Introduction

APLocate is the weather and site location editor for the programs CIBSE Heat Loss & Heat Gains (ApacheCalc), ASHRAE Heat Balance Method (ApacheLoads), ApacheSim, SunCast and Radiance. It is possible to choose a location from an extensive database and guidance is given on defining weather data for various locations. Normally APlocate is called from within the <Virtual Environment> by clicking the APlocate icon. Default site and weather data will be set up when a new model is started. To edit these defaults, create new data or change location you must use APlocate. It is advisable to edit project specific data as soon as the information becomes available. If you begin using the <Virtual Environment> when project data is unknown you may create it at a later date. There are three tabs on the APlocate window, one for location or site data, one for design weather data and the other for simulation weather data. APlocate also has a selection wizard that assists the user in selecting weather data. These are explained in following sections.

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2. Location & Site Data

APlocate utilises site data that contains values for latitude, longitude and height above sea level of a wide range of sites throughout the world drawn from standard tables published by CIBSE and ASHRAE. Non-ASHRAE locations are marked in APlocate with an asterisk (*).

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2.1. Location and Weather Data Wizard

The selection wizard button launches a series of dialogs which help the user select the location, the design weather data and the simulation weather data.

2.2. Location Data

The information in this box is not editable by the user, but whenever a new location is selected or edited in the wizard, it is automatically updated by the program. The final content of this box is saved in the weather data file and can contain any information you like, except that it cannot be left blank.

2.3. Location Data: Latitude

The Latitude within APlocate is expressed as Decimal Degrees North or South. In other words, 20º 30” N should be entered as 20.50 and the drop-down box beside the number set to N. As far as the weather file read by ApacheSim is concerned, the following rule applies: The latitude of the building is expressed in decimal degrees (positive for northern locations, negative for southern locations).

2.4. Location Data: Altitude

Enter the height above sea level of the building. For locations below sea level, negative values are appropriate. The data is used in the calculation of solar gains and atmospheric pressure in Heat Gain. In System Simulation the solar gains and atmospheric pressure are read in directly from the weather file and so this data is not used.

2.5. Location data: Longitude

The Longitude within APlocate is expressed as Decimal Degrees East or West. In other words, 20º 30” E should be entered as 20.50 and the drop-down box beside the number set to E. The building longitude is in decimal degrees. The longitude is regarded as increasing westwards from Greenwich, so 20º East of Greenwich is rendered as entered as 340º.

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2.6. Daylight Saving Time: Time Adjustment

Enter the local time correction applicable for Daylight saving time to those months entered in the From Month and To Month drop-down selection boxes. The value must be approximated to the nearest hour. Positive is in advance of sun time.

2.7. Daylight Saving Time: Daylight Saving Period

This is defined by selecting appropriate months in the From Month and To Month drop-down boxes. Each can be selected within the range January-December. Select the month, during which the time correction entered in the Time Correction Box starts applying. Select the month for which the time correction entered in the Time Correction Box still applies. Note in Northern latitudes, the To month will normally be later than the From Month and in Southern latitudes it will be earlier.

2.8. Daylight Saving Time: Adjustment for Other Months

‘Other Months’ are those months not included in the From Month - To Month period. For example, if the From Month were April and the To Month October (the default condition), then this time correction would be November to March inclusive. Enter the time correction (approximated to the nearest hour) during the remainder of the year as defined above.

2.9. Site Data: Ground Reflectance

This is a measure of the ground albedo (Kr). Typical values are listed below, or in CIBSE Guide A2, Table A2.31. It is used in APcalc and ApacheSim for the calculation of ground reflected radiation on building facades. There is some built-in assistance with setting the reflectance level: Select the More Info button and a table with sample values will appear. You can use the information provided in this window to decide on the albedo level you want to set.

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2.10. Site Data: Terrain Type

Country

Suburbs

City This data is used in both ApacheSim and in external CFD assessments in MicroFlo. The terrain types define how the wind speed will vary with height, dependant upon the local terrain. These definitions are based on ASHRAE 2001 wind speed profiles. This data affects the natural ventilation air exchange rates when MacroFlo is run in conjunction with ApacheSim and the external convective losses in ApacheSim. In MicroFlo the velocity profile changes with height in relation to the choice of terrain type.

2.11. Site Data: Wind Exposure (CIBSE Heating Loads)

Sheltered sites (e.g. city centres)

Normal exposure sites

Sites with severe exposure (e.g. coastal) The appropriate value will be entered into the weather file when a selection is made from the drop-down box labelled Wind Exposure. The wind exposure index is used to calculate the external surface resistance of walls, windows, roofs etc. when a value is not explicitly entered in APcdb. In

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most cases, the peak summertime conditions will occur for a sheltered site. This is because the higher surface resistance levels give rise to higher sol-air temperatures on external surfaces. Higher surface resistance levels also reduce the conduction of heat out of the building at night. For winter heat loss design calculations, the peak conditions occur when the exposure index is set to 3, i.e. severe (but only if your constructions are defined without typing in surface resistance levels). This index is only used for the CIBSE Heating Loads calculation.

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3. Design Weather Data

The individual entries are now explained.

3.1. Design Weather Data Source and Statistics

This section of the dialog contains the information about how the weather data has been chosen using the Selection Wizard. The selection wizard button will take the user through to the design weather data section of the wizard if selected here. The Add to custom database button will allow the design weather data shown currently to be saved by the user.

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3.2. Heating Loads Weather Data: Outdoor Winter Design Temperature

Enter the outside air dry-bulb design temperature applicable to the building location. This number is only used in ApacheLoads and ApacheCalc calculations. This value can be manually entered or is derived from the Weather Selection Wizard.

3.3. Cooling Loads Weather Data

Cooling loads weather data describes the summer time external design weather data. This data is used for both CIBSE and ASHRAE cooling loads calculations. The different parameters that are used for both types of analysis can be viewed by selecting either the ASHRAE or CIBSE analysis radio button.

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3.4. Cooling Loads Weather data: Editing Weather Globally

To globally adjust the cooling loads weather data enter values into the following: Max Outside DB Temperature Max Outside WB Temperature When these figures are entered, select Apply and APlocate will use the selected pattern and shift the data to be based on the maxima as given. This allows you to use an appropriate pattern but provides flexibility in design temperatures. To review the detail of the pattern, press the Apply button. To return to the original values use the selection wizard.

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3.5. Cooling Loads Weather Data: Editing Weather Individually

Custom weather files can be created by modifying the individual values of existing files. Once modified the data values turn a green colour to indicate that a change has been made. To do this, for the parameters common to both CIBSE and ASHRAE for each month from January to December inclusive, the following data are required:

Min Tdb - Minimum Daily Dry-Bulb Temperature – as stated.

Max Tdb - Maximum Daily Dry-Bulb Temperature – as stated.

Tdb lag - Dry-Bulb Time Lag – enter the lag with respect to 12 noon (excluding any local time correction) at the standard time meridian. For example, if you type in 3, here, the dry bulb temperature will peak at 15:00 GMT (or at 16:00 if 1 hour summertime correction is in operation).

Min Twb - Minimum Daily Wet-Bulb Temperature – as stated.

Max Twb - Maximum Daily Wet-Bulb Temperature at Maximum Dry-Bulb Temperature– as stated.

For a CIBSE analysis, the following parameters are required:

Linke Turbidity Factor - describes the combined impacts of various atmospheric factors on the solar beam transmittance – refer to CIBSE Guide Part J Weather, solar and illuminance data for a complete description of this factor.

For an ASHRAE analysis, the following parameters are required:

Solar radiation parameter A

Solar radiation parameter B

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Solar radiation parameter C (ratio of diffuse horizontal to direct normal

irradiation): Parameters A and B are used in the following expression to determine direct normal irradiance:

direct normal irradiance = A*exp(-B/sin (solar altitude))

Please refer to the Climate Design Information section of ASHRAE Fundamentals for a detailed description of these solar radiation parameters.

This data must be entered for 12 months of the year (if you are only interested in summer conditions, just leave the winter data in its default state). APlocate uses this data to generate sinusoidally varying weather data for input to the CIBSE and ASHRAE Heat Gain calculations. Once a new weather data set has been created, this can be entered into the database using ‘Add to custom database’ button. A dialogue box will appear into which the name of the new data set should be entered:

3.6. Cooling Loads Weather Data: Hourly Temperature Variation

The Sinusoidal and ASHRAE standard profile options dictate the way in which the daily cooling loads weather data is generated from the maxima and minima parameters. By choosing the Design Day Graphs or Design Day Tables the effect of either the sinusoidal (to be used in CIBSE Heat Gain calculation) or the ASHRAE standard profile (to be used in ASHRAE Heat Balance cooling load calculation) can be viewed. Either method can be used whether CIBSE or ASHRAE calculations are performed.

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4. Simulation Weather Data

4.1. ApacheSim

Weather Filename (for System Simulation only) This shows the name of the hourly weather data file to drive your building simulation. Clicking the Select button beside the name will give you a list of available sites. The program uses the \IES\apps\Apache directory to store weather files. Each weather file has hourly values of: dry-bulb and wet-bulb temperature, direct normal and horizontal diffuse solar radiation, solar altitude and azimuth, wind speed and direction, cloud cover and atmospheric pressure. Each weather file has a preceding value in kilometres or miles which identifies the distance of its location from the location chosen in Location & Site Data.

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Here is an example of the list you might get to select from:

To select a file: Highlight it, and then click OK. Click Cancel to close the window without having any effect. Annual climate files are used for simulation and IES have a large database for all parts of the world. Two file formats can be read in IES <VE> *.FWT which is the IES <VE> proprietary file type and *.EPW which is a US Department of Energy file format. Contact IES for further information or visit the IES website at www.iesve.com for current available downloads.

4.2. UK Building Regulations Part L

Within this section you select the climate files to be used for Building Regulations compliance with Criterion 1 and 3 of UK Part L. There are currently 14 sites available and these weather files must first be purchased from CIBSE as a separate entity from the IES <VE>. These files are available for purchase on the IES website. Please contact [email protected] if you require more details.

mailto:[email protected]

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5. Weather Selection Wizard

The selection wizard button launches a series of dialogs which help the user select the location, the design weather data and the simulation weather data. The selection wizard allows the user access to choose the Location, the Design Weather, and the Simulation Weather dataset. The selection wizard button appears on both the Location and Site Data tab and the Design Weather data tab. If the wizard is chosen from the Location tab, the user can change the Location, the Design Weather, and the Simulation Weather dataset. If the selection wizard is chosen from the Design weather tab, the user can only manipulate the design weather data. By pressing this button the following dialog will appear:

5.1. Location and Weather Data Wizard

This dialog shows the following location data: Latitude, Longitude, Altitude, Time Zone and Daylight saving time data. These parameters are described in section 2 of this manual. The location and daylight saving time data are all editable. When any data other than Location name is edited, the Location name has an asterisk added to indicate it is no longer from the ASHRAE database. In

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any case the user can edit the Location name as they wish. To access the ASHRAE and CIBSE location database choose the select button:

This shows the Select Site Location dialog. The location of the model can be defined by choosing the correct region, country and city of the site. Non-ASHRAE locations are marked with an asterisk (*). The latitude, longitude and Altitude of the site will then be shown in the non-editable boxes. Note these values can be changed either in the Location & Site Data tab or within the Location and Weather Data Wizard. The drop down list ‘Filter’ helps to sort the data. The filter choices are as follows:

All in country – all locations in the currently chosen country

Nearest 10 – the nearest 10 locations in the database

Nearest 50 – the nearest 50 locations in the database

Nearest 100 – the nearest 100 locations in the database Once the nearest location filter is chosen the locations are viewed along with the distance that the currently chosen site is from the other locations in the list. For example if London/Weather Ctr is chosen and Nearest 10 is chosen from the filter then the dialog will look like the following:

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In the above dialog the closest weather location to the initial choice of London/Weather Ctr is Garston at 11km away. If Garston is now chosen the ten closest locations to Garston will be shown. Note it is possible to select a location in another country if the location lies close to the border. If another country is chosen, the country list will change to reflect this change. Once the correct location is chosen select OK and this will update the previous dialog. If there are no further changes to be made click next.

5.2. Location and Weather Data Wizard: Source of Design Weather

The source of design weather data can be chosen. The options to choose from are to create design weather data from the ASHRAE/CIBSE database, use a custom database, use an older format Apache .apl file or to manually input the design weather.

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5.2.1. Source of Design Weather: ASHRAE Database

If the ASHRAE database is chosen, once next is clicked the following dialog will be shown, here the option is given to use design weather that is not the same as your chosen location. This gives some flexibility for calculations. By choosing select the location for the source of the design weather data can be chosen. The procedure for this is identical to choosing a location for the Location and Site parameters. But this time only locations in the ASHRAE weather database are listed If the location data was edited on the first page of the wizard (5.1) the weather dataset will come up blank on this page. However the Select dialog will come up with the nearest ASHRAE location highlighted.

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Once a location for the design weather dataset is chosen then the user has the choice to decide upon how the design summer and winter external temperature is derived. There are 2 options:

1. ASHRAE Fundamental Design Weather data – tabular weather data taken directly from the ASHRAE fundamentals.

2. Statistical calculation based on ASHRAE WDVIEW 3 data The ASHRAE weather datasets allow these external design temperatures to be based upon a statistical treatment. This treatment analyses the weather dataset and returns the design external temperatures that are only exceeded by the percentage of the year or month that the user specifies.

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If you want to choose an external summer weather design condition where the design temperature is exceeded for 0.2% of the time, enter 0.2 in the Annual percentile for Cooling Loads weather (%). If you want to choose an external design winter condition where the external temperature is colder than the chosen external temperature for 0.4% of the time – enter 99.6 in the Annual percentile for Heating Loads weather (%). Once the percentiles have been set, click on Acquire design weather to generate design weather conditions. This data can later be viewed in the Design Weather Data tab – described in section 3 of this user guide. Note that any edits to the location and/or the percentiles are only effective after an Acquire has been performed. The method by which the design weather is derived from the annual percentiles is as follows. The Outdoor winter design temperature is the hourly average temperature exceeded on the given percentage (Annual percentile for Heating Loads design weather) of occasions in the historical dataset. This dataset is stored as a set of binned temperature statistics. Linear interpolation is applied between consecutive bins. The peak design dry bulb temperature for cooling load calculations is the hourly average temperature that is exceeded on the given percentage (Annual percentile for Cooling Loads design weather) of occasions in the historical dataset. This peak temperature appears in the table as the maximum dry bulb temperature for the warmest month. The percentage of the time that this temperature is exceeded in the peak month is then calculated. This monthly percentile is then applied to the other months to derive the design maximum dry bulb temperatures for those months on the same statistical basis. Minimum dry bulb temperatures are then obtained for each month by subtracting from the maximum dry bulb temperature the daily temperature swing calculated for each month. In the case of the peak month the temperature swing is provided in the database. For the other months the swing is estimated by deriving the amplitude of the first Fourier component of the clear sky horizontal global solar radiation flux for the month in question and using this to scale the temperature swing recorded for the peak month. The wet bulb temperature coinciding with the maximum dry bulb temperature (Twb at max Tdb) for each month is calculated as the mean wet bulb temperature coincident with the maximum dry bulb temperature, using the historical binned temperature data. The peak dry bulb and wet bulb temperatures obtained by this method are in close agreement with those published in the ASHRAE Handbook of

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Fundamentals for the annual percentiles 0.4%, 1% and 2%. The Handbook also publishes monthly dry bulb and mean coincident wet bulb temperatures for monthly percentiles 0.4%, 1% and 2%. There is no fixed relationship between monthly and annual percentiles in general, but for a given temperature the monthly percentile will be greater than the annual percentile (by a factor of about 12 for very low percentiles). The monthly percentile is displayed following retrieval of the design weather data, and a desired value for monthly percentile can be achieved by applying successive adjustments to the annual percentile.

5.2.2. Source of Design Weather: Custom Database

The second source of design weather is a custom database. This database is one created by the user once a current database, which has been edited to user’s requirements, has been saved. The saving procedure, using the Add to custom database in the Design Weather Data tab, is explained in Section 3 of this user guide.

If custom database is chosen, click next and on the following dialog, shown below, choose Select and select from the list of custom databases to choose the design weather.

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5.2.3. Source of Design Weather: Old Format Apache APL File

The third source of design weather is to access the older format Apache APL file. This database gives the user access to the original design weather information supplied in previous versions of APlocate. After choosing the old format Apache APL file select next and the following dialog appears.

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To select an old format Apache APL file choose select and then select the required weather file from the list.

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5.2.4. Source of Design Weather: User Input

If user input is chosen the Design Weather will be left as the current default weather dataset and the user can edit the data as required. This editing is described in Section 3 of this user guide.

5.3. Location and Weather Data Wizard: Simulation Weather File

The simulation weather file can be chosen on the last page of the Location and weather data wizard. To choose from a list of available weather datasets choose the select button. Amore detailed description of simulation weather data files is given in Section 4 of this user guide. You also have the choice of using nearest to site option. When you use this the software chooses the nearest weather file to the site you have chosen. The UK Building Regulations weather file is automatically set when you choose your site location and is a requirement for compliance simulations.

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To save all changes made in the wizard, the Finish button must be pressed.

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6. SunPath

6.1. Purpose of the SunPath Program

The program is designed to show the Sun’s path across the sky on any date as viewed from any position in the earth’s surface. The factors which determine the apparent path are the latitude and longitude of the observer and the date and time of the observation. The Sun’s position is expressed in degrees of azimuth and degrees of altitude. The path is displayed over a period which can be selected by the user. If either of the solstices or the equinoxes occurs during this period, the Sun’s Path for these days is also displayed. By default, the current year for London, UK is displayed, but if SunPath is run from SunCast or from APlocate, then the current location held by these programs is shown. The main screen for the program looks like this:

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To use SunPath, you can select the dates, times and locations you are interested in, and the program will then display the appropriate sun paths and will also carry out a number of analyses. To close the program, click the File and Exit options from the main menu. See the SunPath User Guide for more information.

7. Menu Items

Menu items in APlocate provide the following options:

7.1. File Menu:

Save: Saves the design weather data as a *.wea file Exit: Exits APlocate

7.2. Options Menu:

Graph: Launches the design day graphs dialog SunPath: Launches SunPath (see section 6) Remove from custom database: Option to remove any pre-saved custom databases

7.3. Help Menu:

Contents: Launches the Help menu About: Program description and information about IES

7.4. Toolbar Buttons:

- Save: Saves the design weather data as a *.wea file

- Print: Prints a synopsis of the design weather data

- Graph: Launches the design day graphs dialog

- SunPath: Launches SunPath

- Exit: Exits APlocate

- Help: Launches the Help menu

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