ASHRAE Journal February 1988

An Update: Religious building energy use

An update and expansion of an analysis of the energy use in religious buildings in the Philadelphia area.

By Lawrence G. Spielvogel, P.E. (Member ASHRAE) and Andrew Rudin (Member ASHRAE)
Taken from : American Society of Heating, Refrigerating and Air Conditioning Engineers Journal February 1988 

The Interfaith Coalition on Energy (ICE) was organized 1n 1980 by the Philadelphia area religious community and, funded in 1982 by local private foundations and corporations, began an energy management program for religious buildings whose utility bills are paid by congregations.

Since that time, ICE has completed on-site energy audits for 226 congregations with a total of 546 buildings. Each audit report contains a description of the facilities and their energy systems, a baseline year of energy data, a computation of energy use per square foot, and a list of recommendations to reduce energy costs in order of simple payback.

At one year and two years following the audit, energy consumption and cost data are again gathered from utilities and fuel suppliers.

The data from the buildings and their energy use over three years are entered into two databases. One database contains measured energy data on 366 independently metered buildings. Excluded from this database are the 180 buildings that share meters or fuel tanks with other facilities.

The second, separate database contains 76 charactenstics of the 226 congregations. In addition to the energy and physical data for all monitored facilities, this database contains information on the number of families and the total annual operating budget for each congregation.

ICE has shared its experience with these buildings through the presentation of more than 50 energy management workshops and the distribution of 24 issues of a newsletter.


ICE gathers data on the energy used one year prior to and for two years after the audit. Participating congregations are then sent annual updates on their energy usage. Each database contains one year of pre-audit energy data and follow-up data for none, one or two years after the audit, depending on the time that has elapsed since the audit.

Avoided energy costs are calculated by determining the change in energy units from one year to the next and then multiplying that number of units by the average cost per unit during the most recent year. By calculating costs in this manner, only the savings (or increase) from conservation efforts are determined; savings resulting from electric demand control, fuel oil prices, changing utility rates, and fuel switching are additional and are quite often greater than the savings from conservation.


Follow-up data for the first year after the audit have been gathered for 175 congregations, or 77 percent of those audited to date Second-year data have been gathered for 136 congregations, or about 60 percent of the total number. The total avoided costs for these groups is in excess of $547,000 or $1 ,600 per congregation per year.

This represents first-year avoided costs amounting to eight percent of the total energy expenses from conservation efforts alone. In the second year, the energy use decreased again, but to a lesser degree.

Congregation characteristics

The 226 participating congregations are divided into nine major denominations and several smaller ones. The total floor area of their 546 buildings is about 7,100,000 square feet, with the average congregation having 31,400 square feet. 2.4 buildings, and an annual energy bill of $21,700, or 14 percent of their total operating expense These costs prorated among financially active members of the congregation mean each family contributes $2.42 per week for energy costs alone.

Tables 1 and 2 indicate the energy savings by faith . Table 1 shows the changes expressed in Btu’s per square foot per year, while Table 2 shows the changes expressed in energy units-kilowatthours (kWh) of electricity, hundreds of cubic feet (CCF) of natural gas, and gallons of fuel oil.

(Tables 1 through 18 are available for viewing in the 9 page article, 3.4 megs)

There were wide variations in the extent of energy reductions. The greatest percentage reduction occurred in three United Churches of Christ, which also had the second lowest Btu/sf/yr ranking in the baseline data. The greatest dollar savings occurred in Catholic parishes, where although the percent of energy saved was relatively small, the cost savings for the Catholic buildings over the two-year period exceeded $300,000.

In the Full Article, (Link Below) There are an additional list of 8 important topics in this paper including in-depth information on:

  • Building characteristics
  • Heating
  • Cooling energy
  • Lighting
  • Individually metered equipment
  • Cost reduction
  • Financial motivation
  • National potential
  • Change in Energy Use (by Faith of Congregations) Table
  • Energy Savings over two years (by Faith of Congregations) Table
  • Change in Energy Use (by Building Type) Table
  • Building Energy Use (by year of baseline date) Table
  • Energy Use by Building Size (Both residential and non-residential buildings) Table
  • Energy Use by Building Age (Both residential and non-residential buildings) Table
  • Building Energy Use (by types of heating system control) Table (Manual | 24 hour control | 7 day control)
  • Energy Use by the type of heat distribution (Both residential and non-residential buildings) Table
  • Building Energy Use by the type of heating energy (Both residential and non-residential buildings) Table
  • Heating capacity by square foot Table
  • Building Energy Use by the number of heating zones (Both residential and non-residential buildings) Table
  • Energy Use with summer | winter hookups (Both residential and non-residential buildings) Table
  • Building Energy Use by Heating System Efficiency (Both residential and non-residential buildings) Table
  • Electricity Use and Air Conditioning (By Building Type) Table
  • Separately Metered Central Cooling Table
  • Building Energy Use by Type of Lighting (Incandescent | Florescent | Mixed) Table
  • Separately Metered Use (By Items) Table

To read the full 9 page article in PDF Format, click on the link below:
ashrae_journal_feb_88.pdf  (Opens in a new window, file size 3.45 megs)



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