Code of Maine Rules
18 - DEPARTMENT OF ADMINISTRATIVE AND FINANCIAL SERVICES
554 - BUREAU OF GENERAL SERVICES
Chapter 3 - LIFE CYCLE ANALYSIS
Section 554-3-III - Application

A.1. 0 Purpose: The procedures have been developed in response to actions taken by the Maine Legislature requiring the life cycle costing become a part of the evaluation process for public improvements to assure that energy considerations, first cost, operating costs and long term costs are consistently analyzed as public improvement projects are being considered for approval.

A.1. 1 Goals: It is readily recognized that the life long energy usage of a building is largely determined by the original design and selection of detail equipment. once a building has been erected, it becomes very expensive and difficult to modify construction to accommodate more energy conservation equipment.

A.1. 2 Summary: The purpose of the design standards is not to limit architectural freedom, but is intended to create an awareness that all designs must effectively minimize the use of energy.

B.1. 0 Energy Performance Index (EPI)

B.1. 1 Introduction: The goal of this program is to encourage the development of the most energy conservative building that is consistent with current standards, codes and practices for the buildings intended use.

B.1. 2 Limits: In no instance will total building designed energy consumption exceed the following standards:

C.1. 0 Approved Systems: The ASHRAE's Modified Degree Day Procedure will be used in analyzing the simple heating and ventilation systems. For those systems which involve computing cooling and night setback loads, internal and solar gains, the bin method or computer modeling is required.

Both methods are included in this document (see C.2.0 and C.4.0).

A sample is included in the Appendix A of the Modified Degree Day calculation.

C.2. 0 Modified Degree Day Procedure: (Chapter 43, ASHRAE 1980 System Handbook) The general equation for calculating the probable energy consumption by the modified degree day method is as follows:

E = (Hl x D x 24) (Cd)

(At x N x V)

where

E = Fuel or energy consumption for the estimate period.

Hl = Design heat loss, including infiltration, BTU per hour.

D = Number of 65° F degree days for the estimate period.

t = Design temperature difference, Fahrenheit.

N = Correction factor for equipment efficiency.

V = Heating value of fuel, consistent with H1 and E.

Cd = Interim correction factor for heating effect vs. degree days.

Values of heating load. Hl must be determined for the particular building for which the estimate is being made. It must account for size, building materials, architectural features, use, and climatic conditions. Table 1 gives values for Cd and N.

Table I

Correction Factor Vs. Degree Days Interim Factor Cd

The correction factor N is empirical and should not be confused with any ratings for "seasonal efficiency" The following values shall be used:

N = 1 - Electric Resistance Heating

N = .75 - Pressurized Gas Fired Boiler or System

N = .70 - Oil Fired Boiler with Air Atomizing or Flame Retention

Burner

N = . 65 - Atmospheric Gas Fired System

N = .50 - Coal Fired Boiler Conventional Stoker

N = .65 - Coal Fired Boiler Pressurized Forced Draft Firing System

N = .55 - Old Oil Fired Systems

Note: If other values are to be used, submit verification and backup data.

C.2. 1 Table/Degree Data/Maine

Maine Monthly and Annual HEAting Degree Day Normals

C.3. 0 Hand Calculations Method for Life Cycle Analysis

DATE: ____________________ ARCHITECT ENGINEER:

__________________

LOCATION: ______________ DATA OBTAINED BY: ____

_____________

____________________

Energy needs for buildings can be divided into three basic categories: (1) Base Electrical Loads; (2) Comfort Conditioning System; (3) Domestic Hot Water. The calculation sequence has been segmented accordingly. The analysis must start with an understanding of the proposed building usage and will require detailed data on the sub-components of the electrical and HVAC system. This detailed data should be available as a result of (1) preliminary design and (2) analysis of methods that will optimize energy conservation within the building.

C.3. 1 Base Electrical Load: This section analyzes the annual electrical energy consumption due to the lighting systems HVAC system, (fans, pumps, etc.), exhaust fans, kitchens, shops, elevators, and other specialized operations. A "guideline" comment follows each topic area to clarify the type-of data sought. The diversity factor represents the fact that lighting, for instances is rarely all on or all off.

C.3. 2 Comfort Conditioning System: Similar to the previous section, this section emphasizes the derivation of the annual energy consumption for the HVAC system for space beating and cooling. But since heating and cooling is functionally related to ambient environment, a different technique must be utilized to derive annual energy temperature differential between inside and ambient a separate calculation using "bin" method is necessary. The method statistically arranges weather data in "bins" by day period according to 5° F increments and numbers of hours per year.

C.4. 0 Bin Method: See Chapter 43, ASHRAE 1981 Systems Handbook for General Reference

C.4. 1 Explanation of Forms

C-1 Heating Form (see Appendix C)

C-2 Cooling Form (see Appendix C)

Column 1 Three eight hour periods during the day.

Column 2 Average monthly temperature from weather data.

Column 3 Temperature difference equals temperature inside minus (AVG) temperature outside.

Column 4 "U" value times area equals heat gain or heat loss per degree of temperature, including infiltration & ventilation or greater of the two.

Column 5 Column 3 times Column 4

Column 6 Hours listed in the weather data of each "bin' of temperature.

Column 7 Column 5 times Column 6

Column 8/8a Peak internal load in MBTU: Peak solar load in MBTU.

Column 9/9a Annual Factor in a percentage of the time that the internal available internal & solar gain must be rejected during day occupied cycle.) or solar loads occur, and are useable. (Note: A percentage of the

Column 10 Estimated hours of internal load.

Column 10a Same as Column 6. (For C-2 Cooling Form Only)

Column 11 Column 8 x 9 x 10.

Column 11a Column A x 9a (For C-1 Heating Form Only)

Column 12 Column 7 + 11 + 11a.

C.4. 2 Passive Solar

Values for t in solar analysis shall be determined using the three eight hour periods above.

C.4. 3 Heating Energy

C.4. 4 COOLING ENERGY

C.5. 0 Computer Method for Energy Analysis

C.6. 0 Passive Solar

This section analyzes the energy gains and losses due to southern exposed glass. The windows analyzed under this section should not be included in the previous sections, but shall be added on to obtain the total energy usage in the building.

C.7. 0 Active Solar Analyzing

All active solar systems shall be analyzed separate from this rule and submitted to the Bureau of General Services for review. The designer must compare alternate combinations of heating systems and document. An acceptable Life Cycle Analysis shall include, but not be limited to, the following scope: 10% cost of money, total system cost, system efficiency, total estimated available energy/sq. ft. of panel, total estimated useable energy, component life, and operational and maintenance cost.

Exclusions to this rule are as follows:

D.1. 0 Introduction

Life Cycle Costing is a conceptual extension of the conventional method for awarding contracts to the lowest bidder. Instead of focusing just on the initial costs Life Cycle Costing takes into account the additional costs for energy, operation and maintenance , and system replacements. In this manner, all costs associated with building ownership are fully taken into account when selecting the best alternative design. The overall objective of Life Cycle Costing is more extensive than conventional first cost analysis since it seeks to evaluate the quality of the building over it s lifetime. This concept is especially important when energy costs are rapidly increasing.

D.2. 0 Hand Calculation

The Life Cycle cost evaluation has been established utilizing the uniform annual cost model.

The annual cost model has been developed by forecasting all cost, whether positive or negative, involved with the total system over its projected life. These costs are divided into annual payments taking into account the time value of money for an appropriate interest rate associated with the project.

For the purpose of our project, a 10% rate has been assigned. We have also assigned a 30 year life to the building structure.

Mathematically we are using a uniform recover rate as follows:

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A = uniform end of year sum

P = present value of today's cost.

i = interest rate for period.

y = number of years.

Table has been included with values for given interest and applicable years,

*Material from text by K and G Associates, Box 7596, Inwood Station, Dallas, Texas 75209.

State of Maine FORM "LCA-2,"

DATE _________

D.3. 0 Life Cycle Cost Benefit Analysis PREPARED BY _________ (Reporting Format)

PROJECT ________ DISCOUNT RATE _________

D.4. 0 Interest Table

10% Interest Factors