7.8102.7 Solar Water Heater

Topic: 
Water Heating
Subtopic: 
Installation and Replacement
Desired Outcome: 
Provide a safe and reliable hot water source that meets the needs of the occupant/building management/building operations staff at the lowest possible life cycle cost
Note: 
Solar water heating typically utilizes a backup source. Refer to other domestic hot water generation SWS (e.g., 7.8102.4, 7.8102.5, 7.8102.6, 7.8102.8) for the selected backup source for guidance on installation or removal of those systems
For supporting material, see Referenced Standards and Building America Solution Center.
TitleSpecification(s)Objective(s)
7.8102.7a
Hazardous material removal

Health concerns in the removal and replacement of equipment (e.g., asbestos) will be identified

Upon the discovery of hazardous material, written notification and contact information for regional EPA EPA U.S. Environmental Protection Agency, www.epa.gov asbestos coordinator will be provided to appropriate people (e.g., occupant/building operations staff/property manager)

Property manager will be asked to contract with an EPA EPA U.S. Environmental Protection Agency, www.epa.gov -certified asbestos contractor to conduct abatement before decommissioning and replacement (property manager is responsible for abatement or remediation)

Remediate health hazards using EPA EPA U.S. Environmental Protection Agency, www.epa.gov -certified contractors

7.8102.7b
Decommissioning

Decommission the applicable system components by completing the following in accordance with accepted industry procedures and practices:

  • Remove old water heater and associated components
  • Safely disconnect and secure any abandoned utility (fuel and electric) connections

Ensure worker/occupant/building operations staff/property manager health and safety

Preserve the integrity of the building and services

Remove old equipment in a timely and efficient manner

7.8102.7c
Storage tank accessibility

Storage tank will be installed and plumbed to allow for inspection, maintenance, and replacement of the appliance and its components

Anode rod will be accessible for replacement

Ensure the storage tank can be easily maintained and replaced

7.8102.7d
Solar collector accessibility

Solar collector will be installed and plumbed to allow for inspection, maintenance, and replacement of the appliance and its components

There will be a path that allows the solar collector to be safely accessed without damaging the roof

Ensure solar collector can be easily maintained and replaced

7.8102.7e
Solar collector location

Installation of the solar collector will not exceed the structural capability of the building (e.g., dead load, wind load)

Solar collectors will be sited to minimize shading factor and maximize solar gain

Maximize system performance with minimal negative impacts on the structure and occupant/building management/building operations staff

7.8102.7f
New equipment installation

Solar collectors, storage tank, and associated components will be installed in accordance with local codes, accepted industry standards and practices, and manufacturer specifications

Roof penetrations will be sealed in conformance with the applicable code adopted by the jurisdiction

Ensure the health and safety of the worker/occupant/building operations staff/property manager

Preserve the integrity of the building

Maximize performance

7.8102.7g
Freeze protection

The system will incorporate freeze protection for applicable climates, including, but not limited to, closed glycol loops, drain back systems, supplemental heat, or other methods, as approved by local code and manufacturer specifications

Prevent freezing liquid in pipes in cold weather climates

7.8102.7h
Drain pan

In instances where a leak could cause damage, a drain pan will be installed under the storage tank in accordance with manufacturer specifications and the following criteria:

  • Connected to 3/4" drain line or larger to tapping on pan
  • Run to drain, pump, or daylight

Collect and safely dispose of water escaping from the storage tank

7.8102.7i
Temperature and pressure relief valve

Correct temperature and pressure relief valve will be installed in accordance with manufacturer specifications

Storage tank will be connected to properly sized discharge tube and run to a safe location no greater than 6" from the floor or as prescribed by local code (in the absence of local code, as prescribed by UPC)

Solar collectors will be connected to properly sized discharge tube and run to a safe location, as prescribed by local code (in the absence of local code, as prescribed by UPC)

When applicable, safely discharge excessive energy (pressure or temperature) from the storage tank and collectors to a safe location

7.8102.7j
Dielectric unions (dielectric insulator)

Dielectric unions (dielectric insulator), if needed, will be installed in accordance with manufacturer specifications

Minimize corrosion between dissimilar metals

7.8102.7k
Stray voltage protection

When electric equipment (e.g., pumps motors) is used in conjunction to or connected to the solar water heater, the electrical connection should be made per manufacturer's instructions and per NEC NEC National Electrical Code ( NFPA NFPA National Fire Protection Association, www.nfpa.org 70)

Break the stray voltage electrical circuit through the appliance

7.8102.7l
Backflow prevention

Backflow prevention will be installed in accordance with manufacturer specifications and all applicable codes

Backflow devices shall be tested by a certified backflow assembly tester at the time of installation, repair, or relocation, and not less than on an annual schedule or more often where required by local code

Protect potable water supply from contamination

7.8102.7m
Pipe insulation

All piping and fittings will be insulated with fixed insulation to IECC IECC International Energy Conservation Code or ASHRAE ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers, www.ashrae.org 90.1, at a minimum

Pipe insulation exposed to the sun will be protected from ultraviolet radiation and other damage

Reduce line losses

Prevent insulation from deteriorating

7.8102.7n
Required ventilation and clearances

Ventilation and clearances will be provided under solar collectors in accordance with manufacturer specifications and local code

Prevent damage to solar collectors, mounts, and roof

7.8102.7o
Electric supply

Electric supply components will be installed to accepted industry standards and codes in accordance with NEC NEC National Electrical Code ( NFPA NFPA National Fire Protection Association, www.nfpa.org 70)

Required energy input to the pumps and controls will be in accordance with manufacturer specifications

Provide sufficient electricity to pumps and solar water heating systems

7.8102.7p
Discharge water temperature

Discharge water temperature will be set not to exceed 120 °F or as prescribed by local code

Install mixing valve when higher storage/generation temperatures are required

Ensure water temperature is low enough to prevent scalding

7.8102.7q
Commissioning of system

System design criteria will be checked once the system has been connected and filled, including:

  • Safety controls
  • Operational controls
  • Water leaks
  • Cycle unit modes (e.g., freeze protection, high limit, collection, idle)
  • Other system components (e.g., expansion tank, storage tank)

Manufacturer specifications and all relevant industry standards will be met in commissioning

Ensure the system functions safely and is designed with the lowest possible cost of ownership

7.8102.7r
Education

Completed work will be reviewed

Occupant/building operations staff/property manager will be educated on the safe and efficient operation and maintenance of the system, including:

  • Operational modes
  • Adjustment of water temperature
  • Adjustment of tempering valve
  • Tank maintenance (e.g., anodes, temperature, and pressure relief valve)
  • Fluid maintenance and replacement
  • Solar collector maintenance (e.g., cleaning the collectors, checking gaskets, and mounts)
  • Shade prevention, including trimming nearby trees and vegetation; inform manager/owner/staff that new construction of high-rise buildings on the south side of property may cause shadows, limiting the effectiveness of the solar thermal system
  • Operation of backflow preventer and pressure regulator
  • Importance of keeping operating manuals accessible

Educate the occupant/building operations staff/property manager about the safe, efficient operation and maintenance of the system