Home Energy Efficient Design

This new user-friendly energy design tool shows how much money can save by making changes to your home. 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 then the expert system creates two basecase buildings, one that meets the energy code and another that incorporates more energy efficiency features. Then you can 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 to test various passive solar strategies such as window shading, thermal mass, night ventilation, and high performance glazing. For basic users the easy-to-understand bar charts show how energy bills change with each different design. For experienced users there are more detailed data input options, plus dozens of 3D graphic outputs that reveal subtle differences in of building performance. Clients will especially appreciate how these graphics clearly show the benefits of good energy efficient design.

Link: Building Energy Software Tools Directory : HEED.

Although HEED was developed for ratepayers in California, EnergyPlus climate data files for sites around the world can be read in directly (see read-usa.txt in the download docs folder). HEED can also be used for one-zone non-residential buildings. 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 BESTEST protocol (ASHRAE Standard 140), and against the results of experimental test cell data.

Expertise Required

No 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 familiar with energy efficiency issues, and for energy consultants and engineers working on smaller buildings.

Users

As of October 2004 there have been 6021 downloads. 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: building type, square footage, number of stories, and location. From this the expert system creates the two basecase buildings called "Meets Energy Code" and "More Energy Efficient". The Basic Design information are things that any homeowner would know, and are input by click and drag or by selecting from radio button lists of building components. The Advanced Design inputs are tabular inputs of thermal characteristics, dimensions, schedules, etc.

Output

HEED is unique in that most of its performance data is presented graphically, in a wide array of formats. The Basic output is a bar chart of gas and electricity billing costs for up to nine different schemes. Advanced outputs includes 3D plots for each hour of dozens of different variables including heat gain an loss for seventeen elements of the building’s total load, plus indoor and outdoor 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 40 variables against up to 9 schemes. Tabular data is also available.

Computer Platform

HEED runs on all versions of Windows, from 95 to XP, 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 simplicity of use, ease of input data, a wide array of graphic output techniques, computational speed, and the ability to quickly compare multiple design alternatives. It uses a sophisticated 8760 hour whole-building heat balance simulation algorithm. HEED includes an intelligent whole-house fan thermostat and window-dependent daylighting controls, and calculates the air pollution implications of design decisions. It can automatically manage up to nine schemes in up to 24 different projects. A full Spanish language version is also available, including Advice, Help and the FAQ file.

Weaknesses

Limited to single-zone buildings and generic HVAC systems. Basic Design is limited to four types of residential buildings, but Advanced Design users can input data for any building type (see heed-faq.txt). Currently contains only California electric rates, but they can be user modified. HEED comes with climate data for many California zipcodes and all 16 California Climate Zones, plus it allows Energy Plus climate data for sites around the world to be loaded directly (see read-usa.txt).

Contact

Company:

Department of Architecture and Urban Design

Address:

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

Telephone:

+1 (310) 825-7370

Facsimile:

+1 (310) 825-8959

E-mail:

heed@aud.ucla.edu

Website:

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

Availability

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