ASTM E1056-13(2021)

• Abstract:

  SIGNIFICANCE AND USE; 4.1 This practice is intended to serve as a guide to manufacturers, distributors, installers, contractors, regulatory officials, and owners. It is not intended to specify detailed methods of testing, installation, or servicing for the system or any of its components. ; 4.2 This practice sets forth those methods and components necessary for minimum operation and safety. It also suggests methods for improved operation and effectiveness.; SCOPE; 1.1 This practice provides descriptions of solar domestic water heating systems and sets forth installation and service practices in new and existing one- and two-family dwellings to help ensure adequate operation and safety.2,3 ; 1.2 This practice applies regardless of the fraction of heating requirement supplied by solar energy, the type of conventional fuel used in conjunction with solar, or the heat transfer fluid (or fluids) used as the energy transport medium. However, where more stringent requirements are recommended by the manufacturer, these manufacturer requirements shall prevail. ; 1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. ; 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Sections 6 and 7. ; 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

• Status: Published
• Publication Date: 31-Dec-2020
• ICS: 27.160 - Solar energy engineering
• Technical Committee: E44 - Solar, Geothermal and Other Alternative Energy Sources
• Drafting Committee: E44.20 - Optical Materials for Solar Applications

• Refers: ASTM E772-13 - Standard Terminology of Solar Energy Conversion
• Effective Date: 01-Sep-2013
• Refers: ASTM E772-11 - Standard Terminology of Solar Energy Conversion
• Effective Date: 01-Sep-2011
• Refers: ASTM E772-05 - Standard Terminology Relating to Solar Energy Conversion
• Effective Date: 01-Apr-2005
• Refers: ASTM E772-87(1993)e1 - Standard Terminology Relating to Solar Energy Conversion
• Effective Date: 27-Feb-1987
• Refers: ASTM E772-87(2001) - Standard Terminology Relating to Solar Energy Conversion
• Effective Date: 27-Feb-1987

Overview

ASTM E1056-13(2021), "Standard Practice for Installation and Service of Solar Domestic Water Heating Systems for One- and Two-Family Dwellings," offers comprehensive guidelines for the safe and reliable setup and servicing of solar hot water systems in residential buildings. Developed by ASTM International, this practice supports manufacturers, distributors, installers, contractors, regulatory officials, and property owners in achieving safe, effective, and code-compliant solar water heating system installations. The standard emphasizes minimum requirements for reliable operation and user safety while providing recommendations for enhanced system performance.

Key Topics

• Scope and Applicability:

  • Covers installation and servicing of solar domestic water heating (SDHW) systems in both new and existing one- and two-family homes.
  • Applies to all system types, regardless of the share of heating provided by solar, type of conventional backup fuel, or selected heat transfer fluids.
  • Recognizes that manufacturer recommendations take precedence when they are more stringent than the standard’s provisions.

• System Components & Control Functions:

  • Identifies essential system elements such as collectors, storage tanks, insulation, piping, pumps, controllers, valves, and safety devices.
  • Details requirements for minimum operation and system safety, including freeze protection schemes, pressure relief, isolation valves, and backflow prevention.

• Installation and Service Practices:

  • Recommends practices for correct placement, mounting, and protection of solar collectors and support structures.
  • Stresses the need for adequate insulation, durable materials, proper drainage, leak detection, and provisions for future service accessibility.
  • Outlines methods for freeze protection, including antifreeze fluids, drainback or draindown designs, and use of freeze-tolerant materials.

• Safety and Maintenance:

  • Requires relief valves, mixing valves, leak detection, and devices to protect potable water from contamination.
  • Specifies guidance for owner’s manuals, maintenance logs, and routine inspection procedures for longevity and performance.

Applications

• Residential Solar Water Heating:
  This standard is directly applicable to the installation and maintenance of solar hot water systems in single-family and two-family residences.

• Regulatory and Inspection Compliance:
  Serves as a reference for local code officials and inspectors in approving solar water heating system installations.

• Solar Installer Guidelines:
  Provides installers and contractors with best practices for safe operation, code conformity, and customer satisfaction.

• Retrofit and New Construction:
  Instructions and criteria in this standard cover both new installations and upgrades of existing hot water systems, promoting adaptation to a wide range of residential scenarios.

• Safety and Performance Enhancement:
  By implementing the safety mechanisms and service routines described, stakeholders reduce risk and maximize the system’s lifespan and effectiveness.

Related Standards

• ASTM E772: Terminology of Solar Energy Conversion-essential for understanding key terms used in solar installations.
• SMACNA Standards: Medium Pressure Duct Construction, Fibrous Glass Duct, and Flexible Duct Performance and Installation Standards-relevant for ductwork in air-based solar systems.
• NFPA 321: Basic Classifications of Flammable and Combustible Liquids-critical for selecting appropriate heat transfer fluids.
• ANSI Z21.22: Relief Valves and Automatic Gas Shut Off Devices for Hot Water Supply Systems-providing benchmarks for safety components in solar and conventional heating systems.

Practical Value

• Ensures safe, efficient, and durable installation of solar domestic water heating systems.
• Helps comply with building and plumbing codes and international standardization principles.
• Reduces potential for property damage, health risks, and poor system performance through detailed service and safety recommendations.
• Assists in transitioning to renewable energy in residential applications, supporting energy savings and sustainability goals.

ASTM E1056-13(2021) stands as a vital reference for anyone involved in solar water heating projects, contributing to robust, reliable, and code-compliant installations in residential construction.

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E1056 − 13 (Reapproved 2021)
Standard Practice for
Installation and Service of Solar Domestic Water Heating
Systems for One- and Two-Family Dwellings
This standard is issued under the fixed designation E1056; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This practice provides descriptions of solar domestic 2.1 ASTM Standards:
water heating systems and sets forth installation and service E772 Terminology of Solar Energy Conversion
practices in new and existing one- and two-family dwellings to 2.2 SMACNA Standards:
2,3
help ensure adequate operation and safety. Medium Pressure Duct Construction Standards
Fibrous Glass Duct Construction Standards
1.2 This practice applies regardless of the fraction of heat-
Flexible Duct Performance and Installation Standards
ing requirement supplied by solar energy, the type of conven-
2.3 NFPA Standard:
tional fuel used in conjunction with solar, or the heat transfer
NFPA321 Basic Classifications of Flammable and Combus-
fluid(orfluids)usedastheenergytransportmedium.However,
tible Liquids
where more stringent requirements are recommended by the
2.4 ANSI Standard:
manufacturer, these manufacturer requirements shall prevail.
Z 21.22 Relief Valves and Automatic Gas Shut Off Devices
1.3 The values stated in inch-pound units are to be regarded
for Hot Water Supply Systems
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only 3. Terminology
and are not considered standard.
3.1 Definitions:
1.4 This standard does not purport to address all of the
3.1.1 auxiliary energy subsystem, n—in solar energy
safety concerns, if any, associated with its use. It is the
application, equipment using nonsolar energy sources to
responsibility of the user of this standard to establish appro-
supplement or backup the output provided by a solar energy
priate safety, health, and environmental practices and deter-
system. (E772)
mine the applicability of regulatory limitations prior to use.
3.1.2 flash point, n—of a liquid, the minimum temperature
For specific precautionary statements, see Sections 6 and 7.
atwhichitgivesoffvaporinsufficientconcentrationtoforman
1.5 This international standard was developed in accor-
ignitable mixture with air near the surface of the liquid within
dance with internationally recognized principles on standard-
the vessel as specified by appropriate test procedure and
ization established in the Decision on Principles for the
apparatus. (See Terminology E772 and NFPA 321.)
Development of International Standards, Guides and Recom-
3.1.3 heat transfer fluid, n— (1) in solar energy systems, a
mendations issued by the World Trade Organization Technical
liquid or gas that passes through the solar collector and carries
Barriers to Trade (TBT) Committee.
the absorbed thermal energy away from the collector. (2) any
fluid that is used to transfer thermal energy between subsys-
tems in solar energy systems. (E772)
This practice is under the jurisdiction of ASTM Committee E44 on Solar,
Geothermal and OtherAlternative Energy Sources and is the direct responsibility of
Subcommittee E44.20 on Optical Materials for Solar Applications. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Jan. 1, 2021. Published January 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1985. Last previous edition approved in 2013 as E1056 – 13. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E1056-13R21. the ASTM website.
2 5
Dikkers, R., “Performance Criteria for Solar Heating and Cooling Systems in Available from Sheet Metal and Air Conditioning Contractors National Assoc.
Residential Buildings,” Department of Housing and Urban Development and (SMACNA), 8224 Old Courthouse Rd., Tysons Center, VA 22180.
National Bureau of Standards, September, 1982. AvailablefromNationalFireProtectionAssoc.,BatterymachPark,Quincy,MA
Hollander, P. E., “Installation Guidelines for Solar DHW Systems in One- and 02269.
Two-Family Dwellings,” Franklin Research Center, U. S. Goverment Printing Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
Office, April 1979. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1056 − 13 (2021)
3.1.4 operating conditions, extreme, n— unusual physical 3.2.3 potable water, n—water that is free of impurities in
conditions to which a component or system may be exposed amounts sufficient to cause disease or harmful physiological
and for which it is not designed or intended to withstand, nor effects and conforming in its bacteriological and chemical
is it required to withstand by a local regulatory agency. (E772) quality to the regulations of the public health authority having
jurisdiction.
3.1.5 operating conditions, normal, n—the usual range of
physical conditions (for example, temperature, pressure, wear 3.2.4 reliability, n—the ability (of a system or component)
to operate properly when required.
and tear, weather) for which the component or system was
designed. (E772)
3.2.5 SHW, n—solar hot water.
3.1.6 solar energy system, active, n—a solar energy system
3.2.6 shall, vi—a mandatory requirement necessary to pro-
that uses mechanical equipment (pumps, fans), that is not an
vide minimum operation and safety.
integral part of a structure, to collect and transfer thermal
3.2.7 should, vi—a recommended method or component to
energy, either to the point of use or to be stored for later use.
provide improved performance and effectiveness.
(E772)
3.2.8 toxic, adj—any substance (other than a radioactive
3.1.7 solar water heating systems, direct, n—a solar water
substance) that has the capacity to produce personal injury or
heating system in which the potable water passes directly from
illness to man through ingestion, inhalation, or absorption
the water supply, through the collectors and storage, to the
through any body, surface, or any substance producing a lethal
residential hot water supply. (E772)
dose in half of white rats (LD50) when ingested as a single
3.1.8 solar energy system, drainback, n— a solar energy dose of less than 10 g/kg of body mass.
system in which the heat transfer fluid is drained out of the
collector and exposed piping, and into a storage tank, a holding
4. Significance and Use
tank, or expansion tank inside the building envelope in order to
4.1 This practice is intended to serve as a guide to
protect the collector and piping from damage due to freezing.
manufacturers, distributors, installers, contractors, regulatory
(E772)
officials, and owners. It is not intended to specify detailed
3.1.9 solar energy system, draindown, n— a solar energy
methods of testing, installation, or servicing for the system or
system in which the heat transfer fluid is drained out of the
any of its components.
collector and exposed piping to an external drain in order to
4.2 This practice sets forth those methods and components
protect the collector and piping from damage due to freezing.
necessary for minimum operation and safety. It also suggests
(E772)
methods for improved operation and effectiveness.
3.1.10 solar water heating system, indirect, n—a solar water
heating system in which a closed circulation loop isolates one
5. System Components and Control Functions
fluid from contact with others in the system. This closed loop
5.1 This section covers the system components and related
may contain a nonpotable fluid. (E772)
control functions that are required to collect, transport, store,
3.1.11 solar energy system, thermosiphon, n— a solar en-
and convert the solar energy for typical domestic hot water
ergy system in which the heat transfer fluid circulates by
systems.
convection as the less dense, warm fluid rises and is displayed
5.2 Table 1 shows the recommended system components
by the denser, cooler fluid. (E772)
and related control functions that are required for solar
3.1.12 solar water heating system, tank absorber, n—Solar
domestic hot water systems. Numbers in Figs. 1-7 refer to
Hot Water (SHW) system in which solar radiation is absorbed
components in Table 1.
by the surface of the storage tank, which is usually installed in
5.3 Freeze protection is a necessary subsystem for most
an insulated housing whose sunward side is glazed. Such
SHW systems. Each type of system in Figs. 1-7 provide freeze
systems are also referred to as “integral collector storage
protection by the use of specific components or the nature of
(ICS)”, batch” or “breadbox” heaters.
the system operation. One option for providing freeze protec-
3.1.13 weather conditions, extreme, n—environmental con-
tion for each system is illustrated in Figs. 1-7 (see 6.2 for other
ditions that are rare in a local climatic region (which have
acceptable options). Options may be combined.
occurred no more than once during the past 30 years).
3.1.14 weather conditions, normal, n—the (actual or antici- 6. Installation and Servicing
pated) range of environmental conditions (rain, snow, hail,
6.1 This section outlines recommended installation and
wind, temperature, pollution) that typically occur in a local
servicing minimum practices needed to provide an effective
climatic region over several years. (E772)
SHW system operation.
3.2 Definitions of Terms Specific to This Standard:
6.2 Freeze Protection:
3.2.1 accessible, adj—permitting close approach that may
6.2.1 SHWsystems installed in climates where freezing can
require removal or opening of an access panel, door, or similar
occur shall be protected.
obstruction.
6.2.1.1 Antifreeze Chemicals—Freeze protection may be
3.2.2 durability, n—the ability (of a system or component) accomplished through the use of chemicals either as or in the
to operate properly as long as intended. heat transfer fluid.
E1056 − 13 (2021)
TABLE 1 Solar Domestic Water Heating System Components
Schematic Component Function Text Reference
I.D. No.
1 Solar Collector convert radiant energy into thermal energy 6.3, 7.6.1
2 Solar Storage Tank accumulate thermal energy in the form of solar heated water to 6.4
supply domestic needs
3 Insulation minimize thermal losses from components 6.4.2, 7.6.3, 6.7.3,
6.7.10
4 Piping Fittings interconnect components and convey heat transfer fluid 6.7
5 Mixing Valve limit temperature of domestic hot water delivered for personal use 7.2.10
6 Temperature and Pressure Relief Valve automatically relieves pressure if temperature and/or pressure 6.6.3, 7.2.1 – 7.2.7
maxima are exceeded
7 Auxiliary Heat Source supplements solar energy to provide adequate hot water 6.7.16
8 Pump circulate liquid 6.8
9 Controller controls the collection and distribution of thermal energy within the 6.6
solar domestic hot water system and may provide limited safety func-
tions
10 Auxiliary Storage Tank and Heat Source supplements solar energy to provide hot water and storage 6.7.16
11 Heat Exchanger (internal or external) transfer thermal energy between physically separated fluids 6.8.4–6.8.6, 6.5.2,
7.3.1
12 Air Duct interconnect collectors and heat exchanger in system employing air 6.7
as transfer medium
13 Blower circulate air 6.8
14 Expansion Tank protect system from pressure damage created by expansion of heat 6.6.5
transfer liquid
15 Heat Transfer Fluid Transports thermal energy 6.5, 7.6.2
16 Pressure Relief Valve automatically relieves pressure if maximum is exceeded 6.6.3, 7.2.1 – 7.2.7
17 Check Valve prevent reverse liquid flow 6.6.8
18 Vent Valve release trapped air 6.7.9, 6.7.17
19 Drain Valve to drain fluid passages of liquid; manual or automatic 6.7.8, 6.6.2
20 Backflow Preventer to prevent backflow of non-potable fluid into potable water supply 7.2.2, 7.3.3
21 Vacuum Breaker to relieve a vacuum by permitting air into a system 6.7.17
22 Air Damper control air flow 6.6.4, 6.6.9
23 Shutoff Valves to isolate components; manual or automatic 6.6.3, 6.6.7
24 Temperature Sensor senses fluid temperature to operate controller 6.6.9
6.2.1.2 Automatic Draining—Freeze protection may be ac- system does not operate during periods of power outage unless
complishedthroughtheuseofsystemcontrolswhichautomati- an auxiliary source power is provided.
callyallowheattransferfluidstodrainfrompartsofthesystem
6.2.1.6 Freeze Tolerant Materials—Freeze protection may
exposed to freezing temperatures, as in the draindown or
be accomplished through the use of materials which are not
drainback systems. Electrically operated valves shall drain the
damaged by repeated cycles of freezing and thawing while
system when there is a power outage (that is, fail safe).
filled with potable water, provided evidence that the material
6.2.1.3 Automatic Recirculation—Freeze protection may be
can withstand such cycling is supplied.
accomplished through the use of system controls which auto-
matically circulates heat transfer fluids through the system 6.3 Collector Subsystems:
when outdoor temperatures reach predetermined levels. This
6.3.1 Collectors shall be installed in accordance with the
freeze protection does not operate during periods of power
instructions provided by the collector manufacturer or system
outage unless an auxiliary source of power is provided. This
designer, or both, and in compliance with requirements of the
freeze protection system is not recommended for use in areas
applicable building codes and standards.
with frequent or severe freeze conditions, and may increase the
6.3.2 Structural supports shall be constructed to support the
heat loss of the system during off periods.
collector under anticipated extremes of environmental condi-
6.2.1.4 Manual Draining—Freeze protection may be ac-
tions and to withstand local conditions and anticipated loads,
complished through the use of system controls which allow an
such as wind, seismic, rain, snow, and ice so that the solar
operator to manually drain the system of heat transfer fluids.
system does not impair the resistance to damage of the
Cautionshouldbeexercisedwhendependingonthismethodof
building. Neither wind loading nor the additional mass of filled
freeze protection since it requires human attention for proper
collectors shall exceed the live and dead load ratings of the
operation. Failure to operate the system properly may result in
building, roof, foundation, or soil.
considerable damage.
6.2.1.5 Low Wattage Electric Resistance Heating—Freeze 6.3.3 Structural supports shall be constructed to maintain
protection for tank absorber systems may be accomplished
collector tilt and orientation within design conditions through-
through the use of low wattage (less than 300 W) electrical
out the life of the SHW system.
resistance heaters and system controls that supply heat to the
6.3.4 Joints between support structures and the building
tankandadjacentpiping/fittingsonlywhentemperaturesinside
shall be caulked or flashed, or both, to prevent water leakage.
the system reach 35 + 2°F (2 + 1°C). This freeze protection
E1056 − 13 (2021)
1. SOLAR COLLECTOR
2. SOLAR STORAGE TANK
3. INSULATION
4. PIPING/FITTINGS
5. MIXING VALVE
6. TEMPERATURE AND PRESSURE RELIEF VALVE
7. AUXILIARY HEAT SOURCE
10. AUXILIARY STORAGE TANK AND HEAT SOURCE
15. HEAT TRANSFER FLUID
16. PRESSURE RELIEF VALVE
18. VENT VALVE
19. DRAIN VALVE
23. SHUT OFF VALVES
FREEZE PROTECTION-SHUTOFF VALVES (23) AND DRAIN VALVES (19) ALLOW FOR MANUAL DRAIN-
ING OF THE SYSTEM
h REQUIRED FOR SAFETY OR MINIMUM OPERATION
C FOR INCREASED EFFICIENCY OR AS REQUIRED BY APPLICABLE BUILDING CODE
FIG. 1 Typical Single Tank Thermosyphon System
6.3.5 Collectors shall be installed so as not to contribute to 6.3.9 Collectors and supports shall not create a hazard by
moisture buildup, rotting, or other accelerated deterioration of blocking any means of egress.
roofing materials. 6.3.10 Safe access to components subject to deterioration or
6.3.6 Collectors and supports shall be installed in a manner failure, such as rubber hoses, joint sealants, and cover plates,
that water flowing off the collector surface will not increase the shall be provided to allow for maintenance or repair. For
potential for ice dams or cause water damage, or both, to the roof-mounted collectors, work space adjacent to collectors and
building or premature erosion of the roof. provisions for safe placement of ladders should be considered.
6.3.7 Provisions should be taken to minimize buildup of 6.3.11 Collectors should be installed giving consideration to
snow upon collectors which may reduce their effectiveness. minimizing objectionable glare.
6.3.8 Structural supports shall be selected and installed in 6.3.12 Protection of collectors and components shall be
such a manner that thermal expansion of the collector subsys- provided during handling and installation to prevent damage.
tem will not cause damage to the collector, structural frame, or 6.3.13 Frames,braces,andfastenersusedincollectorinstal-
building. lation shall be made of materials suitable for exterior location.
E1056 − 13 (2021)
1. SOLAR COLLECTOR
2. SOLAR STORAGE TANKh REQUIRED FOR SAFETY OR MINIMUM OPERATION
3. INSULATION
4. PIPING/FITTINGS
5. MIXING VALVE
6. TEMPERATURE AND PRESSURE RELIEF VALVE
7. AUXILIARY HEAT SOURCE
8. PUMP
9. CONTROLLER
15. HEAT TRANSFER FLUID
17. CHECK VALVE
18. VENT VALVE
19. DRAIN VALVE
21. VACUUM BREAKER
23. SHUT OFF VALVE
24. TEMPERATURE SENSOR
FREEZE PROTECTION-MANUAL OR AUTOMATICALLY OPERATED SHUTOFF VALVES (23) AND DRAIN
VALVE (19) ALLOW SYSTEM TO DRAIN
h REQUIRED FOR SAFETY OR MINIMUM OPERATION
C FOR INCREASED EFFICIENCY OR AS REQUIRED BY APPLICABLE BUILDING CODES
FIG. 2 Typical Single Tank Direct System (Draindown)
6.3.14 Collectors shall not reduce the fire rating of the roof 6.4 Thermal Storage Devices:
as prescribed in applicable building codes. 6.4.1 Where heat losses may occur, thermal insulation shall
6.3.15 Required roof penetrations shall be made in accor- be provided on the storage devices and related piping. Insula-
dance with applicable codes and also by practices recom- tion shall be suitable for the application, site, and occupancy
mended by the National Roofing Contractors Association. conditions.
6.3.16 The collector array should not move with frost heave 6.4.2 Care shall be exercised during the installation of the
unless adequate provisions for flexing have been provided. storage device to prevent damage to the device, lining, and
6.3.17 In thermosiphon systems, the bottom of the storage insulation material during handling, mounting or other instal-
tank should be above the top of the collector. lation procedures.
E1056 − 13 (2021)
1. SOLAR COLLECTOR
2. SOLAR STORAGE TANK
3. INSULATION
4. PIPING/FITTINGS
5. MIXING VALVE
6. TEMPERATURE AND PRESSURE RELIEF VALVE
8. PUMP
9. CONTROLLER
10. AUXILIARY STORAGE TANK AND HEAT SOURCE
15. HEAT TRANSFER FLUID
17. CHECK VALVE
18. VENT VALVE
19. DRAIN VALVE
21. VACUUM BREAKER
23. SHUT OFF VALVE
24. TEMPERATURE SENSOR
FREEZE PROTECTION-MANUAL OR AUTOMATICALLY OPERATED SHUTOFF VALVES (23) AND DRAIN
VALVE (19) TO ALLOW SYSTEM TO DRAIN
h REQUIRED FOR SAFETY OR MINIMUM OPERATION
C FOR INCREASED EFFICIENCY OR AS REQUIRED BY APPLICABLE BUILDING CODES
FIG. 3 Typical Two Tank Direct System (Draindown)
6.4.3 If liquid storage devices are provided with overflows, 6.5.2 Toxic heat transfer fluids shall be separated from the
the outlets shall be located so that spillage will not damage the potable water supply by means of a double walled heat
premises. exchanger with leak detection or equivalent protection (see
7.3).
6.4.4 Storage devices located in or above living spaces shall
be installed on a drip pan with a drain line to a waste line or 6.5.3 Heat transfer fluids shall be selected for normal
outside or have some other means of safely removing excess operating temperatures, as well as maximum (no-flow) and
liquid. minimum temperatures.
6.4.5 Fill devices shall be installed with air gaps, backflow 6.5.4 Heat transfer fluids should not accelerate corrosion.
preventers, or some method to prevent contamination of Similar metals, corrosion inhibitors, inert fluids, or sacrificial
potable water supplies as prescribed by applicable codes. anodes should be used.
6.5.5 Heat transfer flu
...