A discussion on hot water system requirements in the 2009 International Plumbing Code -- Part I
By Ron George, CIPE, CPD
President, Ron George Design & Consulting Services
The following code update from Ron George is a two-part series. The following is Part I with Part II to be featured in the April issue of Plumbing Engineer.
The 2009 International Plumbing Code (IPC) addresses domestic hot water systems in several sections, including some general sections of the code; and the code also covers where the domestic hot water supply system is required in section 607 -- Hot Water Supply System. The water heater and water heater accessories requirements are covered in Chapter 5 -- Water Heaters. Although there are various requirements for water heaters, the code is silent with respect to minimum requirements for sizing and selecting of water heaters. There are a few requirements in section 607 covering: hot water temperature maintenance, insulation, controls, thermal expansion compensation and flow of hot water to the left side of a fixture faucet with some exceptions. There are many areas that could use some additional code requirements to provide a better level of safety for code users. The general section of the code covers the scope of the plumbing code in Section 101.2 in the following paragraph.
101.2 Scope. The provisions of this code shall apply to the erection, installation, alteration, repairs, relocation, replacement, addition to, use or maintenance of plumbing systems within this jurisdiction. This code shall also regulate nonflammable medical gas, inhalation anesthetic, vacuum piping, non-medical oxygen systems and sanitary and condensate vacuum collection systems. The installation of fuel gas distribution piping and equipment, fuel-gas-fired water heaters and water heater venting systems shall be regulated by the International Fuel Gas Code. Provisions in the appendices shall not apply unless specifically adopted.
The above text outlines the plumbing systems that are covered in this code. It also tells us that certain provisions for gas fired water heaters are covered in the International Fuel Gas Code.
Code intent:
The intent of the code or the purpose of the code is explained in section 101.3.
101.3 Intent. The purpose of this code is to provide minimum standards to safeguard life or limb, health, property and public welfare by regulating and controlling the design, construction, installation, quality of materials, location, operation and maintenance or use of plumbing equipment and systems.
Existing Installations:
For existing hot water systems or existing plumbing installations they are covered in section 102.2 below and it allows existing installations to continue to be in operation as long as no hazard to life, health or property exists. Many people have argued that the existing systems are "grandfathered" and they should be allowed to continue to be in operation even. When someone is injured in a facility, it is a hazard. If the system presents a hazard then it should be corrected according to the language in section 102.2. Many people have argued that hot water temperatures in excess of 120 degrees Fahrenheit in fixtures intended for bathing, showering or handwashing are dangerous and a hazard to life and health. Many of the consensus industry committees that I have served on also have agreed that the maximum hot water temperature to prevent scalding should be 120 degrees Fahrenheit. Many plumbing code sections in Chapter 4 addressing fixture requirements limit the hot water temperatures to 120 degrees Fahrenheit to prevent a scalding hazard.
102.2 Existing installations. Plumbing systems lawfully in existence at the time of the adoption of this code shall be permitted to have their use and maintenance continued if the use, maintenance or repair is in accordance with the original design and no hazard to life, health or property is created by such plumbing system.
Maintenance:
For maintenance of existing plumbing systems it is covered in section 102.3 below and it requires maintaining the system in proper operating condition and maintaining it in a safe and sanitary condition. This code section also allows a jurisdiction to mandate reinspections of facilities on a regularly scheduled basis if the choose to do so to assure that the facility is being properly maintained. The reinspection could include checking for testing of backflow preventers and checking to see that the maximum temperature limit stops are adjusted properly to limit hot water temperatures at various fixtures to assure safe temperatures that do not create a hazard.
102.3 Maintenance. All plumbing systems, materials and appurtenances, both existing and new, and all parts thereof, shall be maintained in proper operating condition in accordance with the original design in a safe and sanitary condition. All devices or safeguards required by this code shall be maintained in compliance with the code edition under which they were installed.
The owner or the owner's designated agent shall be responsible for maintenance of plumbing systems. To determine compliance with this provision, the code official shall have the authority to require any plumbing system to be reinspected.
Additions, alterations or repairs:
For additions, alterations and repairs of existing plumbing systems the work is covered in section 102.4 below. Any new work on existing plumbing systems cannot cause an existing system to become unsafe. Replacing a water heater, temperature actuated mixing valve, circulating pump or a storage tank, can cause changes to a hot water system such as a different energy input value, heater type, or thermostat setting different from the previous water heater could make an existing system unsafe if the maximum temperature limit stops are not readjusted or if the hot water can be delivered to fixtures used for bathing, showering of washing at a hazardous temperature in excess of 120 degrees Fahrenheit.
102.4 Additions, alterations or repairs. Additions, alterations, renovations or repairs to any plumbing system shall conform to that required for a new plumbing system without requiring the existing plumbing system to comply with all the requirements of this code. Additions, alterations or repairs shall not cause an existing system to become unsafe, insanitary or overloaded.
Minor additions, alterations, renovations and repairs to existing plumbing systems shall meet the provisions for new construction, unless such work is done in the same manner and arrangement as was in the existing system, is not hazardous and is approved.
Change in occupancy:
The same applies for changing the occupancy of a building. For example: If a strip mall had a lease space that was an office space with minimal toilet facilities for employee and public use and it only had a 20-gallon water heater serving two lavatories, it will most likely need to be reviewed for the adequacy of the water heater size and capacity if a restaurant moves into the same space. Depending on the seating capacity and size of the space the facility may need to have additional plumbing fixtures added to meet the requirements of Chapter 4 of the plumbing code and a restaurant has many pluming connections to kitchen equipment that need to be inspected for backflow prevention and there are often fuel gas pressure and capacity issues that need to comply with the fuel gas code. The change in occupancy issue is covered in the following section of the code.
102.5 Change in occupancy. It shall be unlawful to make any change in the occupancy of any structure that will subject the structure to any special provision of this code applicable to the new occupancy without approval of the code official. The code official shall certify that such structure meets the intent of the provisions of law governing building construction for the proposed new occupancy and that such change of occupancy does not result in any hazard to the public health, safety or welfare.
Historic buildings:
There is a section covering historic buildings and once again the key words relative to the grandfather clauses are the inspector verifying existing conditions are safe. For example a two-handled tub or shower valve is not a safe installation, because there is no maximum temperature limit stop on a two-handled tub filler or shower valve. The two-handle valve installation can be made safer by the installation of a temperature actuated mixing conforming to ASSE 1017 (located at the source) or and ASSE 1070 device (located near the point of use) and a pressure balancing valve conforming to ASSE 1066 (located in the hot and cold water supply lines to the fixture). The code text for historic buildings reads as follows:
102.6 Historic buildings. The provisions of this code relating to the construction, alteration, repair, enlargement, restoration, relocation or moving of buildings or structures shall not be mandatory for existing buildings or structures identified and classified by the state or local jurisdiction as historic buildings when such buildings or structures are judged by the code official to be safe and in the public interest of health, safety and welfare regarding any proposed construction, alteration, repair, enlargement, restoration, relocation or moving of buildings.
Plumbing fixtures, faucets and fixture fittings:
Chapter 4 of the International Plumbing Code covers specific requirements for plumbing fixtures in alphabetical order. The requirements for Bidet's limit the water temperature to 110 degrees Fahrenheit with the use of an ASSE 1070 device. This is for obvious reasons as the bidet water is used on sensitive areas and often the user is in a compromised position while using the bidet. The bidet water temperature text is as follows:
2009 International Plumbing Code, Chapter 4 -- Fixtures, Faucets and Fixture Fittings
408.3 Bidet water temperature. The discharge water temperature from a bidet fitting shall be limited to a maximum temperature of 110 F (43 C) by a water temperature limiting device conforming to ASSE 1070.
Emergency fixtures:
The code addresses emergency showers and eyewashes, and many years ago I submitted a code change to include the standard ISEA Z358.1 as the standard that covers emergency showers and eyewashes. Prior to this, the code said emergency fixture need to be supplied with an adequate supply of cold water. In many northern climates and some southern climates, it is not unusual to see the cold water temperatures drop below 40 degrees Fahrenheit (F) in the winter months. The ISEA committee is made up of only manufacturers of safety equipment, but they put the standard out for public review and I have provided comments to the ISEA working group for inclusion in the standard. A friend that has served on the Z358.1 main committee for many years told me there is no specific temperature mentioned in the standard because they cannot agree on a specific temperature range. In the past the appendix listed a temperature range between 60 degrees and 90 degrees Fahrenheit (F). There were comments about 60 degrees F being too cold for someone to stand in a shower for the full 15-minute period required to flush a chemical off of the body if there was an accident and at 90 degrees there may be a chemical that could react so someone familiar with the chemicals should be consulted for an appropriate temperature. To my knowledge, there have been no studies done on hypothermia related to flowing water from an emergency shower and its effect on the users relative to hypothermia. There are numerous studies by the coast guard on hypothermia for victims submerged or floating in lake or ocean water. In those cases there is a boundary layer of water around the body that warms up. In a shower situation there is a constant flow of water and there is also an evaporative cooling effect to consider. In my own personal testing experience with flowing water, I found that the water temperature should be at least 70 degrees before it was not so cold that it took my breath away or would discourage my use of an emergency fixture. This temperature could vary a degree or two depending on the individual. As the water rose from 70 degrees F to 80 degrees F, the more comfortable the water felt to me. There were also discussions that for eye washes, temperatures over 100 degrees Fahrenheit could cause damage to the eyes. My own recommended design would be to install an ASSE 1071 temperature actuated mixing valve for emergency fixtures and set it a 80 degrees. I can be set at any temperature by the facility medical, chemical, maintenance or safety personnel since they are familiar with the chemicals present at the facility. If you were to install a temperature actuated mixing valve that is set at 80 degrees Fahrenheit, it would probably operate between 75 and 85 degrees Fahrenheit. ASSE 1071 is the industry standard that covers temperature actuated mixing valves for emergency fixtures. The valves have an additional safety feature to provide a cold water bypass in the event of an over-temperature situation. A temperature actuated mixing valve designed for domestic hot water distribution systems does not have the cold water bypass feature and should not be used to provide "tepid" water to emergency fixtures. Care should be taken to route water supplies to emergency fixtures and emergency fixture mixing valves where the pipes will not be affected by freezing temperatures, high temperature equipment, high or low temperature piping or direct sunlight. These situations have all caused temperature and performance problems in the field. The ISEA Z 358.1 standard could not require "tempered" water for the supply to emergency showers because "tempered water" is defined in the plumbing code as water having a temperature range between 85 degrees Fahrenheit and 110 degrees Fahrenheit. These temperatures are not appropriate for emergency fixtures so the committee used the word Tepid to describe the water temperature for emergency fixtures. The code text is as follows:
411.1 Approval. Emergency showers and eyewash stations shall conform to ISEA Z358.1.
Temperature limits for tempered water for public hand washing facilities are covered in section 416.5 of the IPC. The ASSE 1070 device is intended to serve a single fixture or multiple fixtures. There have been some states that require a separate device for each fixture unnecessarily, but the local code must be followed in those jurisdictions and additional valves must be installed in order to be compliant in those jurisdictions. The text covering tempered water for public hand-washing facilities is as follows:
416.5 Tempered water for public hand-washing facilities.
Tempered water shall be delivered from public hand-washing facilities. Tempered water shall be delivered through an approved water-temperature limiting device that conforms to ASSE 1070 or CSA B125.3.
Temperature limits and allowable devices for individual showers are covered in section 424.3 of the IPC. The temperature limits is 120 degrees Fahrenheit for showers. The text is as follows:
424.3 Individual shower valves. Individual shower and tub-shower combination valves shall be balanced-pressure, thermostatic or combination balanced-pressure/thermostatic valves that conform to the requirements of ASSE 1016 or ASME A112.18.1/CSA B125.1 and shall be installed at the point of use. Shower and tub-shower combination valves required by this section shall be equipped with a means to limit the maximum setting of the valve to 120 F (49 C), which shall be field adjusted in accordance with the manufacturer's instructions. In-line thermostatic valves shall not be utilized for compliance with this section.
Temperature limits and allowable devices for gang showers are covered in section 424.4 of the IPC. For single temperature installations the valve is typically set to a comfortable bathing temperature around set by the facility personnel at about 100 to 105 degrees Fahrenheit. The bather typically does not have individual temperature controls when an ASSE 1069 device is installed. The bather would simply have an on/off valve or a metering button. Gang showers are common in schools, prisons, health clubs and other institutions applications. There are temperature limits is 120 degrees Fahrenheit for gang showers. When individual shower controls are used the shower must have both hot and cold water supplied to it and then an ASSE 1016 device would be appropriate to control the water temperature and it has a maximum temperature limit stop at 120 degrees Fahrenheit. The text is as follows:
424.4 Multiple (gang) showers. Multiple (gang) showers supplied with a single-tempered water supply pipe shall have the water supply for such showers controlled by an approved automatic temperature control mixing valve that conforms to ASSE 1069 or CSA B125, or each shower head shall be individually controlled by a balanced-pressure, thermostatic or combination balanced-pressure/thermostatic valve that conforms to ASSE 1016 or CSA B125 and is installed at the point of use. Such valves shall be equipped with a means to limit the maximum setting of the valve to 120 F (49 C), which shall be field adjusted in accordance with the manufacturer's instructions.
Temperature limits and allowable devices for bathtub and whirlpool bathtub valves are covered in section 424.5 of the IPC. The temperature limits is 120 degrees Fahrenheit for showers. The text is as follows:
424.5 Bathtub and whirlpool bathtub valves. The hot water supplied to bathtubs and whirlpool bathtubs shall be limited to a maximum temperature of 120 F (49 C) by a water-temperature limiting device that conforms to ASSE 1070 or CSA B125.3, except where such protection is otherwise provided by a combination tub/shower valve in accordance with Section 424.3.
Temperature-Actuated Flow Reduction Valves:
Temperature-actuated flow reduction (TAFR) valves are addressed in section 424.7. They are not required by code because there are several options for providing a safe shower, lavatory or tub filler temperature. This code section simply states, if they are installed they must conform to the ASSE 1062 standard. Temperature actuated flow reduction valves protect against scalding only and do not prevent temperature fluctuations or thermal shock associated with pressure imbalances that cause temperature fluctuations in the plumbing system. The devices are designed to shut down the flow of water to a drip when the temperature exceeds about 115 to 117 degrees Fahrenheit. The device allows a small drip of water flow through the device after it has actuated to allow the user to readjust the temperature controls to a cooler temperature and allow the cool water to reset the device. These TAFR devices are a good and inexpensive device for building owners to install between the shower arm and the shower head in applications where there are dangerous hot water temperatures to prevent scalding. There are also TAFR devices that screw into the tub filler spouts and TAFR devices that screw onto faucet aerators
424.7 Temperature-actuated, flow reduction valves for individual fixture fittings.
Temperature-actuated, flow reduction devices, where installed for individual fixture fittings, shall conform to ASSE 1062. Such valves shall not be used alone as a substitute for the balanced pressure, thermostatic or combination shower valves required in Section 424.3.
The 2009 International Plumbing Code (IPC) also addresses domestic hot water systems in Chapter 5 Water Heaters. The water heater and water heater accessories are covered in this chapter. Although there are various requirements for water heaters, the code is silent with respect to minimum requirements for sizing and selecting of water heaters types or capacities for a given application.
Part II of this column can be found in the next issue of PE.
Ron George is president of Ron George Design & Consulting Services. He has served as Chairman of the International Residential Plumbing & Mechanical Code Committee. He is active in plumbing code and plumbing product standard development committees with ICC, IAPMO, ASSE, ASME, ISEA and ASTM. His company specializes in plumbing, piping, fire protection and HVAC system design and consulting services. He also provides plumbing and mechanical code consulting services and he provides investigations of mechanical system failures and litigation support. To contact Ron, w-mail: rgdc@rongeorgedesign.com.