HEED

HEED logo.

This user-friendly energy design tool shows how much money you can save by making changes to your home. It also shows how much greenhouse gas (including CO2) it accounts for, and its annual total energy consumption. HEED (Home Energy Efficient Design) works equally well for remodeling projects or designing new buildings.

You begin by giving four facts about your building, and the expert system creates two basecase buildings, one that meets the energy code and another that incorporates more energy efficiency features. Then you can copy one of these and begin to create your own unique designs. First draw in your home's proposed floorplan, rotate it to the correct orientation, then click and drag windows to their exact location on each facade. Copy this to successive schemes and try out various passive solar and energy efficient design strategies such as window shading, thermal mass, night ventilation, and high performance glazing, etc.

For basic users the easy-to-understand bar chart shows how the energy coat, annual energy consumption, or CO2 production will change for each different design. For experienced users there are detailed data input options, plus dozens of 3D graphic outputs that reveal subtle differences in building performance. Clients will especially appreciate how HEED’s various graphics outputs clearly show the benefits of good energy efficient design.

Although HEED was developed for ratepayers in California, your own local utility rates and greenhouse gas factors can be loaded. EnergyPlus climate data files for sites around the world can be read in directly (see read-usa.txt in the download docs folder). Screen Shots

Keywords

whole building simulation, energy efficient design, climate responsive design, energy costs, indoor air temperature

Validation/Testing

HEED has been validated against the ASHRAE Standard 140, HERS BESTest Tier 1 and Tier 2, and in a five year experimental test cell program. It has also been validated in actual instrumented occupied low income housing units over two summers (all results available on HEED web site.).

Expertise Required

o special expertise is required in the Basic Design section, so homeowners and ratepayers will recognize all the terms. The Advanced Design and Evaluation sections are intended for designers, builders and contractors familiar with energy efficiency issues, and for energy consultants and engineers working on smaller buildings.

Users

As of January 2008 there were 14,792 users. A survey in April 2002 showed 16 % of the users were in Southern California, 7% were elsewhere in California, 48% were elsewhere in the US, and the remaining 29% were in another country. (Survey results available on the web site.)

Audience

Homeowners and ratepayers will be comfortable with the Basic Design section of HEED which requires no special vocabulary or expertise. Designers and Energy Consultants, familiar with energy efficiency issues, will appreciate the features of the Advanced Design and Evaluation sections.

Input

To start HEED only four facts are required: location, building type, square footage, and number of stories. With this the expert system creates the two basecase buildings called "Meets Energy Code" and "More Energy Efficient". From this point users can copy and revise up to seven more schemes to more precisely represent their building and to test various energy design alternatives. Floor plans can be easily drawn in using HEED’s fill-in-the-squares technique. Windows can be clicked and dragged to their correct size and location on each façade. The building can be graphically rotated to its correct orientation (see screen shots). The Basic Design information is input by click and drag or by selecting from check lists. The Advanced Design inputs are tabular inputs for all variables in the program including thermal characteristics, dimensions, schedules, etc.

Output

HEED is unique in that all of its performance data is presented graphically, in a wide array of formats. The basic output is a bar chart of fuel and electricity annual costs using local utility rates for up to nine different schemes. This bar chart can also show comparative annual energy consumption and the CO2 production, and total annual (site) energy consumption. Advanced outputs includes 3D plots for each hour of dozens of different variables including heat gain an loss for sixteen elements of the building's total load, plus outdoor and indoor air temperatures, air change rate, furnace and air conditioner outputs, power for lights and for fans, and gas and electricity costs. There are also 3D bar charts comparing over 50 variables against up to 9 schemes. Tabular data is also available.

Computer Platform

HEED runs on all versions of Windows from 95 to Vista, and also on Mac OS 10.2 or later.

Programming Language

HEED graphic user interface is written in Java and C++. The Solar-5 computation kernel is written in Fortran.

Strengths

HEED's strengths are ease of use, simplicity and clarity of input data, a wide array of graphic output techniques, computational speed, and the ability to quickly compare multiple design alternatives. It can calculate the window-specific daylight reduction of electric lighting loads. It includes an intelligent whole-house fan thermostat and window-dependent operable solar controls. HEED calculates the air pollution implications of design decisions. It can automatically manage up to nine schemes which can be assembled into any number of projects. It includes context specific Help, internet based Advice, and an FAQ file. A full Spanish language version is also available.

Weaknesses

Works best for single-zone buildings, although it can aggregate up to four adiabatic zones. It has generic HVAC systems. Operating schedules in the current version are limited to residential buildings. It contains utility rates for California’s five major utilities, but they can be user-modified for most types of rate structures. HEED comes with climate data for all 16 California Climate Zones, both of which can be accessed for hundreds of California zip codes. HEED can also directly read Energy Plus climate data for over a thousand sites around the world (see read-usa.txt).

Contact

Company:

Energy Design Tools Group at the UCLA Department o

Address:

Box 951467
University of California at Los Angeles
Los Angeles, California 90095-1467
United States

Telephone:

+1 (310) 206-7021

Facsimile:

+1 (310) 825-8959

E-mail:

energy.design.tools@ucla.edu

Website:

http://www.aud.ucla.edu/energy-design-tools

Availability

HEED can be downloaded at no cost from the web site.