Building Energy Software Tools
Formerly hosted by US Dept. of Energy    

Error message

User warning: The following module is missing from the file system: file_entity. In order to fix this, put the module back in its original location. For more information, see the documentation page. in _drupal_trigger_error_with_delayed_logging() (line 1128 of /var/www/

ENERWIN - Annual energy simulation for new or existing buildings.

Reviews 0

ENER-WIN© is a Windows-based hourly energy simulation model for evaluating whole-building energy performance. The program features an interactive graphical interface for input and output. The simulation model uses algorithms that permit hour-by-hour energy calculations in minimal time. The program's tabular results include monthly and annual utility energy and costs, peak HVAC loads, a thermal comfort analysis and a life-cycle cost summary. It has a Visual Basic interface and a FORTRAN-95 simulation engine that features transient modeling based on sol-air temperature, time lag, and decrement factor; zone loads and temperatures based on a thermal balance methodology; and daylighting algorithms based on a modified Daylight Factor methodology. The software contains default data bases populated with weather data for over 2030 cities worldwide, lighting power densities based on 40 building types in ASHRAE's energy-efficiency Standard 90.1. The latest version, Enerwin-e9 lets the user select from three different standards (90.1-2007, 90.1-2010, or the Standard 189.1 for Green Buildings.) Enerwin-EC is similar but is based mostly on U-Factor requirements from Standard 90.1-2007. The e9 version adds significant precision in selecting the default wall and roof U-factors and window solar heat gain coefficients (SHGC), in that these are now sensitive to not only the building type selected, but also the particular code selected and the climate zone represented by the selected city. Ventilation rates, as well as occupancy densities, are based on the ASHRAE Standard 62.1-2010 for acceptable indoor air quality. Occupancy and other 24-hour profiles, such as lighting and hot water usage, are based on sources that have been involved in energy simulations for buildings, particularly the U.S. DOE and the COMNET (Commercial Buildings Energy Modeling Network) organizations. Enerwin-e9 has three separate schedules ("Mon-Fri", "Sat", and "Sun") for each building type and for each of the usage parameters (occupancy, hot water use, lighting, receptacles (plug loads), fans and ventilation, summer thermostat settings, and winter thermostat settings.) Versions EC and e9 include the calculation of greenhouse gas emissions caused by the building's energy consuming systems. If gas or oil are used for on-site heating, the emissions are calculated directly from the fuel consumption. Emissions for all electricity use are calculated at the power plant, showing values for gas-fired, oil-fired, and coal-fired generators. Emissions are calculated in terms of tons (short or metric) of Carbon Dioxide (CO2), Sulphur Dioxide (SO2), and Nitrous Oxides (NOx).

Expertise Required: 

Knowledgable in building architectural and thermal feature descriptions, thermal load calculations, HVAC equipment and zoning, and climate terminology. General familiarity with ASHRAE energy Standards 90.1-2007, 90.1-2010, 90.1-2013 and 189.1. Ability to layout building plans into thermal zones.


Building designers, energy code officials, architects, engineers, energy analysts, students of architecture and engineering.


Specification of energy code being used, city (for climate data selection), building type (function), energy costs and economic parameters such as economic life, escaltion rate, discount rate, and building geometry and feature description. Plans and HVAC zoning are input through a built-in drawing package. Selection of user profiles, equipment schedules, lighting schedules, and temperature profiles.


Hourly, monthly and annual energy consumption for all building components, peak heating and cooling loads, annual hours of cooling and economizer cooling, hourly thermal comfort by seasons of the year, Excel-ready spread sheet of most energy results. Life-cycle cost analysis. Annual production of greenhouse gases. Monthly and annual utility bills.


Built-in weather data simulator, using statistical weather data base from 30 years of recorded data for 2030 cities worldwide. Built-in drawing package for describing the building plans for single and multi-story buildings. Very quick annual energy analyses, taking typically from 2 to 10 seconds to produce results. Very easy reycling to repeat simulations after changing any chosen parameters of building features, climates, codes, etc.

Developed in the USA, useable in both IP and SI units worldwide.
Major Capabilities: 
Code Compliance
Free To Try
Last Software Update: 
30 June 2010
Last Entry Update: 
07 November 2015
Add to compare