Steven Winter Associates, Inc 307 Seventh Avenue Suite 1201
Building Systems Consultants New York, NY 10001
BTU/Sq Ft/HDD Calculator
Beta test version 1.0
1. This Calculator is currently in draft form and has been provided to you for testing purposes only.
2. The calculator, its calculations and content are the sole property of Steven Winter Associates, Inc. (SWA) and
may not be copied or re-used without written permission.
3. The Beta test version 1.0 has a margin of error that fluctuates based on the amount of data entered. Users are
cautioned about providing more or less than a year's worh of fuel usage.
4. SWA makes no gaurantee that the calculations in the Beta Test version 1.0 are accurate. These calculations
are meant to demonstrate approximate energy performance and do not substitute for technical consulting
5. Heating Degree day information is averaged over a period of years and is based on data from publically
available weather sources. Future versions of this calculator will match actual annual HDD information to the year
of fuel record input.
6. Any questions about the Calculator, its purpose, intended use and development schedule should be addressed
to: Cecily Channell, Steven Winter Associates, Inc. (212) 564-5800 ext 13.
INSTRUCTIONS FOR USE
1. Select the calculator tab below to access the calculator.
2. Follow directions in Blue text - input data only in YELLOW highlighted areas.
3. Green highlighted areas are calculations based on your inputs.
4. Print the calculator using the print commands in excel - results are pre-formatted to print on one page.
Step by Step Instructions
1. Enter the building or project name
2. Select the type of fuel your building uses. The Beta test version 1.0 calculator only accepts natural gas and #2,
#4 and #6 oil.
3. Specify the start and end of the heating season for this building. The calculator must recognize these inputs as
4. Collect fuel records for the year 2005. This should include the last date of oil delivery/gas reading in 2004.
4. Input reading or period dates and fuel usage starting in row 1. The first reading date will be the last date in
2004. Enter records for one year only (or as close as possible) and include CONSECUTIVE READINGS only.
Enteringthe building area MORE THAN one year of records will impact calculation results and will result in a
5. Input LESS THAN or (square feet)
6. Select a region from the drop down list to access annual Heating Degree Day information. The Beta test
version 1.0 has several options, choose the city that is closest to your area in climate.
7. The calculator will determine annual fuel usage for Domestic Hot Water (DHW) and Heating. It will also
determine the BTU/Sq FT/HDD.
Contact Cecily Channell, Steven Winter Associates, Inc. at: firstname.lastname@example.org, (212) 564-5800 ext 13
Multifamily Building Energy Usage Calculator (BTU/Sq-FT/HDD)
Instructions: Enter information into yellow fields (following directions in blue text. Do not alter any white or gray cells.)
Building Name/Address 305-315 East 88th Street NYC
Input Fuel Type and Usage Information
1. Select a fuel type from the list below #6 Oil
Fuel Type Units Gallons
2. Indicate Start & End of Heating Season
Start 1-Oct The heating season in the New York City area starts on October 1st and ends on May 31st.
3. Input One Year Of Fuel Records
Input delivery/reading dates and fuel usage starting in row 1. The first PERIOD START will be the last date in 2004. Enter records for one year only (or as close
as possible) and include CONSECUTIVE READINGS only. Entering LESS THAN or MORE THAN one year of records will impact calculation results and will result
in a greater margin of error.
# Reading Start Delivery/Reading Usage (Gallons) Service Provided # of days Gallons/Day
1 1/1/2005 1/31/2005 8,166 Heat and Domestic Hot Water 31 263
2 2/1/2005 2/28/2005 8,772 Heat and Domestic Hot Water 28 313
3 3/1/2005 3/31/2005 5,349 Heat and Domestic Hot Water 31 173
4 4/1/2005 4/30/2005 2,456 Heat and Domestic Hot Water 30 82
5 5/1/2005 5/31/2005 2,440 Heat and Domestic Hot Water 31 79
6 6/1/2005 6/30/2005 2,446 Domestic Hot Water Only 30 82
7 7/1/2005 9/30/2005 2,443 Domestic Hot Water Only 92 27
8 10/1/2005 10/31/2005 2,415 Heat and Domestic Hot Water 31 78
9 11/1/2005 11/30/2005 2,166 Heat and Domestic Hot Water 30 72
10 12/1/2005 12/31/2005 2,829 Heat and Domestic Hot Water 31 91
Total Reported Usage (1.00 years) 39,481 365 108
Calculated Fuel Usage for Domestic Hot Water (DHW)
Total DHW Only Fuel Usage (Gallons) 4,889 Note: If you do not show any DHW Only fuel usage, change the Heating Season dates (in
Total DHW Only Days 122 question 3) to include summer usage recorded in step 3.
Reported Fuel Usage - DHW (Gallons/Day) 40.08
Annualized Fuel Usage - DHW 14,628 37% Percentage of Fuel to Make Hot Water
Calculated Heating Usage
Total Reported Usage (1.00 years) 39,481
(# of Years) 1.00
Annualized Usage 39,481
Less Annual DHW Only Usage (14,628)
Annual Heating Usage 24,853
Calculated BTU per Square Foot Per Heating Degree Day (HDD)
Annual Heating Usage (Gallons) 24,853
Conversion Factor (BTUs/Gallons) 155,000
Annual Heating Usage (MMBTUs) 3,852
4. Input The Total Building Area (sq-ft) 73,878
BTU's Per Square Foot 52,144
5. Select a Region New York
Annual Heating Degree Days (HDD) 4,804 Definition: A degree day gauges the amount of heating or cooling
needed for a building using 65 degrees as a baseline. To
calculate a Heating Degree Day, subtract the daily
temperature from 65.
Efficiency Rating : Your building is within the average for this area. You could lower this number by implementing basic energy
BTU / Sq-Ft / HDD BTU/Sq-Ft/HDD BTU/Sq-Ft/HDD Scoring Category
0 - 4.99 There must be a problem. Make sure you have ALL fuel accounts and accurate building data.
5 - 8.99 Congratulations! Your building is a high performance building!
9 - 17.99 Your building is within the average. You could lower this number with basic energy improvements.
18 - 29.99 Your building is a high energy user. Consider energy efficient building improvements.
30 + There must be a problem. Make sure you have accurate fuel accounts and building data.
11/22/2011 Prepared by Steven Winter Associates, Inc. d24d1f71-fdc9-46e8-9a42-81a0e4d5f8e8.xlsx