Hot Water Delivery Systems in the ICC Green CodeACEEE Hot Water Forum

Topics

Introduction to the IgCC

Hot water delivery in IPC and IECC

Hot water delivery systems in the IgCCSystem designRecirculationPipe insulation

Additional water heating efficiency measures

Introduction to the IgCC

Works with existing codes, does not replace existing codes.

IgCC is designed to work with ICC’s family of codes.

Adds broad-based sustainability to the life, health, & safety focus of the traditional codes.

Does NOT trump the existing codes. Where a conflict exists, local codes, laws, and regulations take precedence

What is a Green Code Overlay?

Applies to traditional commercial AND high-rise residential buildings

Residential portions of buildings (except high rise residential) covered by ICC-700 (NGBS)

Applicable to new construction, alterations, and additions

Provides criteria to measure compliance & drive green building into everyday practice

Scope

Subject AreasEnergy efficiency

Alternative energy sources

Water efficiency

Alternate water sources

Materials and resource use

Indoor environmental quality

Global impact

Site design and impact

Operation and maintenance

Existing buildings

Hot Water Delivery Systems in the IPC and IECC

Setting the Foundation

Delivery Systems in the IPC –Minimum Pipe Sizing

Minimum size of 3/8” permitted to supply (IPC Table 604.5):BidetsDrinking fountainsLavatoriesWater closet flush tanks

Volume reduction from 3/8” to ½” pipe ranges from 37% for Type M Copper to 46% for SDR9 PEX

Reduced size flexible water connectors permitted between supply pipe and fixture.

Delivery Systems in the IPC –Parallel Plumbing

Further reductions in individual fixture supply lines permitted for parallel systems.

Bathtubs, Kitchen sinks, Laundry, Showers, One-piece Water closetsDeveloped length must be 60’ or less and pressure at meter must be at least 35 psiMinimum size may be reduced by one pipe size from Table 604.5

Section 604.10 provides manifold sizing provisions for different nominal sizes, and 4 or 8 feet per second velocity.

IPC/IECC Requirements for Recirculating Systems

Hot Water Delivery Systems in the IgCCRaising the Bar

Piping System Types in the IgCC

Everything ElseTrunk and branchCentral manifoldRemote manifoldCombinationsEtc.

Circulating

Efficient Hot Water Delivery Systems

Reduces water and energy waste by limiting the total volume in hot water pipes.

87 ounces between hot water source and outlet for most systems.32 ounces from the loop for circulating systems.IgCC Table 702.8.2 provides volume values per length for most piping types.Includes: Pipe, fittings, valves, meters, manifolds

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Basis for Volume Limits

Rationale was to provide significant water savings while preserving a range of system design options and costs. In a word – BALANCE.

Flexibility needed to encompass various types of projects and uses.Recognizes that commercial installations vary widely and can include long runs.Lower volumes create a de facto requirement for recirculation inmost commercial systems.

Lower volume for recirculation systems reflects higher likelihood of use in commercial and also likely to be engineered

Volume Thresholds Compared

Nom.64

Nom.87

Nom.32

Recirc.64

Recirc.32

Recirc.16

0

20

40

60

80

100

WaterSense IGCC IAPMO Supplement

Basis for Volume Limits

Core/Compact System:

Feet of Copper Diameter Vol per ft Location of tubing Total Gal. Total Oz.25 3/4" 0.0251 Water heater to remote manifold 0.6275 80.35 1/2" 0.0121 Manifold to fixture 0.0605 7.7

Total System Volume 0.688 88.1

Basis for Volume LimitsCentral Manifold Distribution System:

Feet of PEX Diameter Gal. per ft Location of tubing Total Gal. Total Oz.10 3/4" 0.0182 Water heater to manifold 0.182 23.330 1/2" 0.0092 Manifold to fixture 0.276 35.31.4 1-1/4" 0.1 14 port manifold 0.14 17.9

Total System Volume 0.598 76.5

Volume Verification

IgCC requries that the volumes be verified by means of design calculations and/or measurements onsite.

Discussion regarding bucket/stopwatch method

Ultimately rejected over concerns about temperature transition profile.Would require that the volume threshold be increased compensate – could create inaccuracies.

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Recirculating Pump Controls Permitted (IgCCC 608.2)

TIMER-BASEDOR

THERMOSTATIC MOMENTARY CONTACT SWITCHMOTION SENSORSFLOW SWITCHDOOR SWITCH

608.8 (2) Requirements for Motion Sensor Controls

Sensor(s) to make momentary contact when motion is sensed.

After the signal is sent, the sensor must go into a lock out mode for not less than 5 minutes to prevent sending a signal to the electronic controls while the circulation loop is still hot.

Pipe Insulation Requirements

Required for all service hot water pipes (IgCC 608.7)

Exception for fixture connectorsException for cases where pipe is completely surrounded by blown-in or sprayed insulation.

T > D

D

(k = 0.22 to 0.28 BTU-in/h-ft2-F)

Summary

IgCC is a commercial code overlay with performance and prescriptive tracks for energy compliance.

IgCC is designed to work with other ICC codes like the IECC, IMC, IBC and IPC.

Development is through ICC’s consensus process. Dates to remember:

Public Comment: March 15 – May 14, 2010Hearing: August 14-22, 2010 in ChicagoPublic Version #2 Release: November 3, 2010Proposals Due for 2012 IgCC: January 3, 2011

Questions?Robert GuentherDirector of Mechanical ProgramsICC Plumbing Mechanical and Fuel Gasbguenther@iccsafe.org