FREQUENTLY ASKED QUESTIONS about HEED (Home Energy Efficient Design)

HEED can be downloaded at no cost from its own web site (www.energy-design-tools.aud.ucla.edu/heed). The size of the download will be about 60 megabytes (MB). Upon installation, the program will require upwards of 800 MB of hard disk space. (Mac Version: The size of the download will be about 80 MB and the program will require about 250 MB of hard disk space. It will automatically use Spanish if it is set as the preferred language in International preferences.)

Once you have downloaded it, run the installation setup program by double clicking on its icon on your desktop, or by clicking on it in your download file. It starts by asking where you want store it, but we strongly recommend that you use the default directory folder (c:\heed) especially if you have an NT machine. In any case you must use folder names that are not more than eight (8) characters long. Using the normal “Program Files” directory may cause an error because an installation that uses long filenames will lead to error messages like “Could not find the main class. Program will exit.”

If you are using an old Windows XP you might experience erratic behavior because XP sometimes adds extra hidden file extensions. For example STATION.DAT is sometimes changed to STATION.DAT.DAT but you cannot see the last DAT. To make these extensions visible go to My Computer, Control Panel, Folder Options, View, and un-check “Hide Extensions.” Use Rename to eliminate the extra extensions. (Mac Version: After downloading, open the HEED disk image file [if it isn’t already open] and drag the HEED icon to your Applications folder [or to wherever you prefer to put it].)

You can upgrade HEED by installing a new version in the same directory as the old version, and your old data will be preserved as long as it is compatible. However if HEED did not install correctly or if you find one of the schemes or projects does not run properly, you can save your old data folders by renaming heed\solar5 to heed\solar5X and then re-installing HEED. If that works, it means that there was an incompatibility or error somewhere in the old data. Alternatively you might just need to erase the schemes or project that is causing the problem. (Mac Version: All HEED data is stored in the Application Support folder of your Library folder [/Users/username/Library/Application Support/HEED].)

When I tried to launch HEED I got the message, “Could not find HEED main class, program will exit.” This usually means that your download was incomplete or corrupted. This could also mean (on Windows) that the directory path you entered has filenames longer that eight (8) characters (see the previous FAQ-2). Try to re-install, but if that fails, download HEED again and be sure the installation runs to completion.

This usually means that your computer does not have enough memory. You also may have other programs loaded and running at the same time which you should close temporarily. If neither of these solves the problem, you may need a more technical solutions such as reducing the number and size of command-line arguments, or reducing the environment size or removing unnecessary environment variables. Since HEED uses a DOS based calculation kernel (on Windows), the default DOS environment may need to be restored or modified.

The most common cause is that there are too many windows and solar collectors and too many external objects, because HEED needs to calculate the shade cast by every external object on every window or solar collector for every hour of the year. First try reducing the number of trees. In the most complex case it might run for at least half an hour, but do not worry it will produce accurate results.

There are various other causes of slow performance, but the most common one is insufficient memory. A second cause of slow performance is having other programs loaded and running at the same time. Another common problem is that your Virus protection software may be checking all the files that HEED is writing to the hard drive; as a test this can be at least temporarily disabled.

HEED runs on macOS version 10.11 or later.

The California Energy Commission has divided up the state into 16 different climate zones, and HEED contains a climate data file for each. For example there are 9 different climate zones in the Southern California Edison service territory, and some zipcodes cross between two climate zones. For Location you can load either 1 to 16 for the climate zone, or load in the California zipcode directly. Outside of California you will need to download the EPW file for your location, and then select it by name.

For each of the 16 California Climate Zones HEED contains the 16 WYEC (Weather Year for Energy Calculations) files in EPW (Energy Plus Weather) format. These files contain temperature and radiation data for each of the 8760 hours in the year. Using the Library icon HEED will also automatically download and install Energy Plus Weather (.epw) files for hundreds of stations around the world (see READ-EPW(Automatic) on the web site). This is not average (or mean) data, but rather the year is assembled from twelve actual “typical” months taken from different years. This means it shows the correct annual and monthly averages, but also the extremes, storms, and weather patterns that actually occur. (Mac Version: EPW files for various locations can also be downloaded from energyplus.net/weather. Place the EPW files in the tmy folder of your HEED data folder [/Users/username/Library/Application Support/HEED/tmy].)

HEED will now also directly read EnergyPlus (.epw) files for hundreds of stations around the world (see READ-USA.TXT in the heed\solar5\docs folder [on Windows]). There is a direct link to the EnergyPlus site on the HEED web page. If you have your own raw temperature and beam and diffuse radiation data, you can create a TMY format file (see READ-TMY.TXT in the \docs folder [on Windows]), although the process is very complex. Windows users who have trouble using their own data should consult this file for a discussion of hidden file extensions and how to eliminate them. (Mac Version: See the previous FAQ.)

Energy costs are calculated using the latest rates approved by your local California utility (SCE, SDG&E, PG&E, SCG, SMUD) as defined for California zipcodes. Because rates can change every month, we use an average rate calculated over a recent year (see the Rates screen for details). You can also input data from your own utility’s current rates if you wish on the Advanced Design Rates screens. We recommend that you download the latest version of HEED to be sure you are using the most current rates and the latest program features.

Yes, we recommend that whenever you begin a new project that you always go to the Library icon and click on “create a new project,” and give it the most unique and descriptive name you can think of. Each new project can have up to nine different schemes. Whenever you make a design change, do it on a copy of your best prior scheme. If you run out of schemes, copy the project, erase the old schemes, and copy your best scheme to Scheme 3, and keep going.

Your data for each set of schemes is automatically saved every time you recalculate, so when you log on next time be sure to click on “Use prior schemes,” and not on “Start from scratch” which will open a brand new project.

This usually means that you did not get a complete download, so the EXE file is corrupted. Check that the size of your “heed_install.exe” program is about 60 MB, and if not, download it again.

This may mean that the computation kernel did not run for some reason. Hit Recalculate again and look for the Calculating popup. It could also mean that there is corrupt data in one of the input screens, although we believe that there are error traps to catch all illogical data inputs. Sometimes this means that you climate data is corrupted so try another zipcode, or something is our of date so download the program again and click Recalculate Old Project.

Yes, by using SBEED (Small Building Energy Efficient Design) which allows you to select non-residential building types, and automatically loads different hourly schedules and utility rates, and different equipment and plug loads.

Some EnergyPlus climate data files produce a latitude of 0.0 degrees. Note that HEED does not run for the Southern Hemisphere with negative latitudes.

HEED is limited to the Northern Hemisphere, sorry.

Check the Evaluation Shadows and Sunlight screen to see that some of them extend along the curb beyond the edge of the site. In fact any time windows are left at the curb any shadows that fall on them will be ignored. It is always better to place them correctly on the building and recalculate.

If you are having trouble running the Spanish version of HEED, be sure that language default on your computer is American English, or American Spanish (which will keep dollars). If you are in Latin America, for example, your default version of Spanish is not compatible.