Comments to ASHRAE Standard 191P Section Comment / Suggested Change Explanation Foreward: What does food preparation have to do with HVAC water system use? Should this be in a separate paragraph? 1. Purpose and 2. Scope Both sections clearly state that the intent of this standard is to provide baseline requirements, not stretch or green standards. However, the standard clearly exceeds true baseline requirements in many areas with no consideration or justification regarding economic payback. The standard needs to be revised to establish true baseline standards or label this standard as a stretch standard and rely on the International Mechanical Code (IMC) with recent additions for a defensible baseline. Additionally, there is no building size threshold that this standard applies to (i.e., does this apply to a small gas station?) nor is there a distinction between residential (i.e., a single family home) and non residential applications. This can put an unnecessary burden on small buildings and single family housing while creating confusion in the industry. Closed Circuit Cooling Towers: a type of cooling tower that uses two separate fluid circuits, a process circuit and an external circuit, to extract waste heat via an evaporative cooling process. Closed loop systems involve no direct contact between the process fluid (typically water, or glycol, or refrigerants) and the atmostphere or the recirculated external water. Also known as an "indirect" cooling tower. Reason: More accurate. Cooling Tower: a heat rejection device, which extracts waste heat to the atmosphere through both latent and sensible heat transfer by allowing water to evaporate, transferring heat energy to a moving air stream to be exhausted. Evaporative heat rejection devices are commonly used to enable provide lower system energy usage water temperatures than achievable with "aircooled" or "dry" heat rejection devices for airconditioning, manufacturing, and electric power generation. Cooling towers can be are either both open and closed circuit systemdesigns. Reason: More accurate, clearer definition.
Cycles of Concentration (COCs): Cycles of Concentration are defined as the ratio of the makeup rate to the sum of the blowdown and drift rate. The COCs can also be monitored by calculating the ratio of the chloride ion, which is highly soluble, in the system water to that in the makeup water. The number of COCs is dependent on the composition of the makeup water, particularly the quantity of minerals and their quantity contained in the makeup water supply. It would also be good to show the calculations for COCs. Evaporative Condenser: hheat transfer device in which refrigerant vapor is condensed in coils that are cooled by the evaporation of water flowing over the outside of the tubes. These systems usually incorporate an air fan system for forced air movement, a recirculating water pump, a water spray system, and a cooling coil. See also Cooling Tower. The definition for Evaporative Coolers should be further clarified for direct and indirect evaporative coolers. Facility Operations: a facility is operational during the time when the primary activity that facility is designed for is taking place. For Group A and Group M occupancies, this is the time during which the facility is open to the public. Reason: More accurate, clearer definition. Drift can be considered as part of the blowdown as this is also a loss of water from the tower, though typically very small. Reason: More accurate, clearer definition. Define group A and M occupancies. Hybrid Wet/Dry Closed Circuit Coolers and Evaporative Condensers: hybrid heat rejection equipment contains both wet and dry heat transfer modes and offers the benefits of saving water with dry operation and saving energy while operating in the evaporative mode. Open Circuit Cooling Towers: a specialized heat exchanger transfer device in which two fluids (air & water) are brought into direct contact to affect transfer of heat energy. Cooling is achieved through a combination of latent and sensible heat transfer and evaporation of a small percentage of the circulating water is evaporated. Should a definition for add on evaporative precoolers used for condensers be added? Reason: More accurate, clearer definition. Reason: More accurate, clearer definition. 4.1 Scope There is no size criteria. Provisions can be justified on larger buildings, but questionable on small buildings.
4.3.1.2 4.3.1.2 Landscapes shall be designed to reduce supplemental irrigation water use by a minimum of 4030% from the baseline for those improved landscape areas as calculated in EPA s Water Sense budget tool as provided on their website. There is no justification offered to exceed EPA s recommendation of a 30% reduction in water use for this baseline standard. The use of a minimum of also encourages landscapers to exceed the reduction rather than just comply with the reduction. Additionally, the EPA spreadsheet is marked Beta on their website; additionally, the final version of the spreadsheet should be made available on the ASHRAE website so that continuity can be maintained if the tool is discontinued or revised on the EPA website. In the scope there are no size criteria. This probably can be justified on larger buildings, but questionable on small buildings. 4.3.5.2 4.3.5.2 Where not expressly prohibited under the regulations established by the AHJ, alternative water source(s) shall only be utilized for aany vegetative roof irrigation required shall only use alternative water source(s) except where expressly prohibited under the regulations established by the AHJ.
4.3.6.1 5.2 4.3.6.1 Water use shall comply with the following: ornamental fountains and other ornamental water features shall be supplied either by alternate, on site sources of water or by municipally reclaimed water delivered by the local water utility acceptable to the AHJ. Fountains and other features shall be equipped with: (1) makeup water meters, (2) leak detection devices that shut off water flow if a leak of more than 3.7 L (1.0 gal) per hour is detected, and (3) equipment to recirculate, filter, and treat all water for reuse within the system. Potable water shall not be used for this purpose. Exception: Where municipally reclaimed water is not available within 1000 ft of the building project site, or alternate on site sources of water are not available in sufficient quantity for the intended purpose, or where the use of the alternate water source(s) increases the risk of water related disease as determined by a qualified water professional, potable water is allowed to be used for start up and makeup water. All alternate sources shall meet the water quality requirements of the AHJ. The use of alternate on site sources of water shall comply with IAPMO Green Plumbing and Mechanical Code Supplement, Chapter 5, or ICC Green Construction Code, Chapter 7, and meet the ANSI/NSF 350 or 350 1 standard for water quality or the standards set by the AHJ. What is the justification for inclusion of makeup water meters and leak detection systems on fountains, especially given that no fountain size limitation is included? In addition, alternate sources of water, depending on the specific water quality, can contain biological contamination which can be amplified by use in an ornamental fountain or water feature, justifying the addition of this exception (note 5.3 refers to this situation). The water quality requirements must be listed in the Standard rather than simply the reference standards. Without the specific requirements included, proper compliance cannot be attained, it is unfair to force users to acquire other standards for compliance with this standard, and raises the risk of changes in the other standards subverting the intent of this standard.
If municipally reclaimed water is available within 1,000 feet of the property boundary, it shall be used for all landscape irrigation water requirements and for cooling tower makeup, toilet, and urinal flushing except where cost prohibitive or not feasible because of health concerns, such as medical facilities where immune compromised patients may be present. Clarifies the exception for cooling towers and reclaimed water by making this an exception rather than a note. Note: Cooling tower makeup water using non potable sources shall meet evaporative heat rejection equipment manufacturers recommended water chemistry guidelines. Exception: Potable water can be used for cooling tower make up if the non potable water sources do not meet the evaporative heat rejection equipment manufacturers recommended water chemistry guidelines. 5.3 There should be some minimum quality requirements for use in cooling towers as the impact on fouling and corrosion could be significant and may increase energy consumption. 5.3.1 A minimum building size should apply. 5.3.2 The water quality requirements must be listed in the Standard rather than simply the reference standards. Without the specific requirements included, proper compliance cannot be attained, it is unfair to force users to acquire other standards for compliance with this standard, and raises the risk of changes in the other standards not meeting the requirements intended in this standard. 5.3.2 Can this be cost justified for residential buildings? Define residential. A residence where people sleep. 5.3.2 5.3.3.1 Residential: construction or materials that are expressly intended for and/or are designated by the AHJ as appropriate for use in providing living accommodations. At a minimum, potential uses for the alternate sources of water shall be quantified on a daily basis based on monthly climatic and operational factors. These potential uses that shall be quantified shall include: While reclaimed water is often satisfactory for cooling tower use, many of the alternate sources of water listed can be problematic for use in cooling towers. 1. Cooling tower makeup (excluding cooling tower bleed). 21. Landscape irrigation, including irrigation of vegetative roofs.
5.3.3.2 5.3.3.2 Other potential uses of non potable water that may be included in the analysis includes, but is not limited to: 1. Flushing of plumbing fixtures. 2. Priming of floor drains. 3. Other beneficial uses as identified and approved by the AHJ. Exemption: The applicant is exempt from these provisions if the potential use of reclaimed or on site sources of nonpotable water is less than 250 gallons of water per day or the sum of the sources of reclaimed or on site sources of nonpotable water is less than 250 gallons per day. 5.3.4 Need to tie to a minimum building size For a baseline standard, a threshold of 250 gallons per day is not cost justified. Per the AWWA, the average water cost for the U.S. is $1.50 per 1,000 gallons. Even at 10x this cost, 250 gallons per day is only $3.75/day, hardly a level to justify the expense of such systems (so at 37.5 per day this requirement is far from justified in a baseline standard). The limit for a baseline standard must be much higher to be economically justified. Furthermore, this limit will vary by locality, water costs, treatment costs to make the alternate water supply usable, etc. Thus there should be no requirement to use alternate sources of water but instead requirements for use of alternate water sources, when justified needs to be included in the standard. Trying to force users to incorporate alternate sources Note: makeup water using non potable sources shall meet evaporative heat rejection equipment manufacturers recommended water chemistry guidelines 5.4.2 Should be defined. Suggest you work with manufacturers to develop a consensus and not leave it open
5.4.3 For sites where municipally reclaimed water is not available, a minimum of one half of the non potable, on site alternate sources of water identified in 5.3.1 shall be reused on site if acceptable uses for that water identified in 5.3.3.1 are present and the use of that water has less than a 10 3 year simple payback, which shall include all costs for the reclaimed water system, including but not limited to first cost, ongoing maintenance costs, and both initial and ongoing testing costs. A certified water professional will determine the usability of these sources and tthe AHJ will confirm the determine the usability of these 5.4.3 sourcesconclusions of the water professional. 5.6 Who are the submittals sent to? For a baseline standard, 10 years is too long a payback period for the use of alternate water sources. Three years or less in more common and all costs for the system must be accounted for (keeping in mind that money for an alternate water system could also be used for other purposes, such as the purchase of more efficient HVAC or lighting systems. Furthermore, AHJs may not be qualified to determine the usability of alternate water sources, which should be the responsibility of a certified water professional. 6.3.3.1 Table 6 2 6.3.3.3 6.3.3.4 The standard claims to not covering processes, but processes are listed (i.e. car wash). Will all processes be excluded? Subsystem Sub Metering Threshold Cooling Towers Primary flow > 30 L/s (500 gpm) >3,800 L/day (1,000 gal/day) 6.3.3.3 Meter Data Collection. All building meters and submeters installed to comply with the threshold limits in 6.3.3.1 shall be configured to communicate water consumption data to a meter data management system. Meters shall provide data a minimum of daily and shall record a minimum of hourly consumption of water. 6.3.3.4 Data Storage and Retrieval. The meter data management system shall be capable of electronically storing water meter and sub meter data and creating user reports showing calculated hourly, daily, monthly, and annual water consumption for each meter and sub meter and provide alarming notification capabilities. justification offered for inclusion of make up and blowdown submeters on a cooling tower, nor for a remote reading and data storage system, for a baseline system (though a user may choose to do so as part of their water treatment plan in place of a conductivity probe, which is the typical method). Metering requirements for large, multi cell installations are also likely to be problematic from a piping viewpoint. Likely the metering requirements for other subsystems are not justified either (i.e., evap coolers,
6.3.3.3 6.3.4.1 6.3.4.1.1 Table 6.3 6.3.4.2.1 Table 6 4 6.4.2 Why doesn't the standard require a water management system? p Systems. For the purposes of this section, sources of hot or tempered water include water heaters, boilers, hot water circulation loops, and electrically heat traced pipe. The volume of water in the piping between water heaters or boilers and fixture fittings the serve shall not exceed 32 ounces (0.945 L). The volume of water contained in fixture branch piping that connects to a hot water circulation loop or electrically heat traced pipe shall not exceed 16 ounces (0.47 L). The volume shall be calculated in accordance with Table 6 3. 6.3.4.1.1 Volume Calculation. The volume of water between the source of hot or tempered water and a given outlet shall be calculated by adding the internal volume of all piping, fittings, valves, meters, and manifolds between the source and the outlet. Piping volumes shall be calculated using Table 6 3. Where water is supplied by a circulating hot or tempered water system or an electrically heat traced pipe, the hot water source shall be the loop or the heat traced pipe, and the volume shall include the portion of the fitting on the loop that supplies the fixture branch. Delete While reduction of hot water system volume is worthwhile, this borders on micromanagement and does not belong in a baseline standard on water use. While reduction of hot water system volume is worthwhile, this borders on micromanagement and does not belong in a baseline standard on water use. While reduction of hot water system volume is worthwhile, this borders on micromanagement and does not belong in a baseline standard on water use. 6.3.4.2.1 Pipe Insulation. Piping shall be thermally insulated in accordance with Table 6-4. Building cavities Pipe insulation is wellcovered by other energy and interstitial framing spaces shall be large enough to accommodate the combined diameter of the pipe plus codes such as Standard 90.1 the insulation, plus any other objects in the cavity that and does not belong in this the piping must cross. standard. Pipe insulation is wellcovered by other energy codes such as Standard 90.1 and does not belong in this TABLE 6 4 MINIMUM PIPE INSULATION THICKNESSa standard. 6.4.2 The prescriptive option is met if the project achieves a 30 percent reduction in water use when compared to typical water use for a building of the same type.
6.5 Performance Option A method or source is needed to establish the typical water use for a building of the same type. Otherwise, this requirement will be subject to gamesmanship and be rendered meaningless. What is a typical building? 6.5 Table 7.1 6.5.1 If the performance option is followed, a document describing how the plumbing systems meet the water demands or a document that describes the method implemented to increase water efficiency shall be submitted to the AHJ. 6.5.2 The performance option is met if the project achieves a 30 percent reduction in water use when compared to typical water use for the same building typology using methodology pre approved by the AHJ. Subsystem Threshold Values for Sub Metering Requirement Cooling Towers and evaporative heat rejection equipment (meter on makeup water and blowdown) Cooling tower flow through tower >500 gpm (30 l/s) Evaporative Coolers, air washers Makeup water >0.6 gpm (0.04 l/s) Steam and Hot Water Boilers >500,000 Btu/h (50 kw) input Additionally, this section applies to Plumbing Systems, yet the requirement is a 30% reduction in water use for a typical building. Is this requirement for the entire building or just the plumbing system? This is unclear in the standard. There is no economic justification offered for inclusion of makeup and blowdown submeters on a cooling tower, nor for a remote reading and data storage system, for a baseline system (though a user may choose to do so as part of their water treatment plan in place of a conductivity probe, which is the typical method). Metering requirements for large, multi cell installations are also likely to be problematic from a piping perspective. Likely the metering requirements for other subsystems are not justified either (i.e., evap coolers, boilers, etc.). Either drop the requirement or make the threshold(s) the same as any large water using process. Drop the requirement for remote data collection and storage the first cost and maintenance of these meters will be expensive,
7.3.4 7.3.5 7.3.6 7.3.7 7.4.1 7.4.1 7.4.1 If the drift is less than these numbers can eliminators be dropped? Provide cost analysis. 7.3.5 Cooling tower blowdown stream water shall be recovered for reuse in accordance with the local AHJ. 7.3.6 Building projects located in regions where the ambient mean coincident wet bulb temperature at 1% design cooling condition is greater than or equal to 72 F (22 C) shall have a system for collecting condensate from air conditioning units with capacities greater than 65,000 Btu/h(19 kw), and the condensate from all steam systems shall be recovered for reuse. 7.3.7 General. Baseline Minimum Energy Efficiency Requirements equipment shall comply with ASHRAE 90.1 2010, Efficiencies Standard Rating and Operating Conditions, and comply with Sections 5.4, 6.4, 7.4, 8.4, 9.4, and 10.4 of ANSI/ASHRAE/IESNA Standard 90.1 2010. Equipment shown in Tables 6.8.1A, B, C, D, F, G, H, I, and J of ASHRAE Standard 90.1 2010 shall meet the minimum requirements at the specified rating conditions when tested in accordance with the specified test procedure. 2. Hybrid Wet/Dry Coolers and Condensers: Design shall incorporate hybrid heat rejection equipment to optimize water use and reduce the demand on potable or nonpotable makeup water. 1. Water Treatment Plan 2. Hybrid Wet/Dry Coolers and Condensers Provide Cost Justification 3. Cooling Equipment Designed for Non Potable Water Makeup: Evaporative cooled heat rejection equipment shall be designed to accommodate makeup water from the specific non potable source(s) used in the system, whether including rainwater, stormwater, air handler condensate, recycled treated wastewater foundation drain, or reclaimed municipal water, or some combination thereof. This requirement is not justified in a baseline standard and no economic justification is offered. This is more appropriate for a stretch standard like 189.1. While on the surface a good idea, building energy requirements in a water standard will lead to confusion in the industry. Simply say compliance with efficiency standards. This requirement, as written, requires all evaporative heat transfer equipment to be hybrid designs, which is not justified as a prescriptive requirement, especially in a baseline standard. Should be tied to a minimum building size. For example, is this really justified on a 1 ton evaporative cooler? 7.4.1
7.4.1 7.4.1 7.4.1 7.4.2.1 7.4.2.1 3a. Makeup water from non potable sources shall meet evaporative heat rejection equipment manufacturer s recommended water chemistry guidelines. What do you do if it does not comply? Provide minimum quality specification 4. Non Chemical Water Treatment: When used, the blowdown from evaporative heat rejection equipment with non chemical water treatment shall be recovered for reuse. Exception: Blowdown shall not be recovered from nonchemical water treatment systems that require the use of additional chemical water treatment. 5. Mechanical Filtration: Mechanical filtration shall be utilized for the removal of solids 44 micron and larger (visible solids) in cooling water systems and shall recover purge and or backwash water for reuse. Define building performance model. Models for small buildings can be very expensive (~$5k per building per Energy+ model) Because energy savings correlates to water savings, a building performance model shall be used to minimize the total evaporative heat load by minimizing the airconditioning load through building thermal efficiency features and shall include an analysis for the potential of cold thermal storage systems and heat recovery. As written, evaporative equipment must be designed for all of these water sources, yet the design for one of these non potable sources may be very different from another. Therefore the design should be for the specific water quality of nonpotable water available at the site. Often, non chemical water treatment systems must also use chemical for proper water treatment, whether it be a corrosion inhibitor or secondary biocide. These additional chemicals may be problematic in a non potable water reuse system. Filtration is not required on most systems, is relatively expensive, and is a parasitic energy use (especially if not required on a system). There must be a legitimate, justifiable need for filtration to be called for, especially in a baseline standard, even if a prescriptive option. A prescriptive requirement for an expensive building model for buildings with evaporative cooling systems amounts to a restraint of trade. If a building model is called for, it must be called for on all buildings especially as water is also used in the production of energy and reducing load will save water at the building and/or at the power plant.
7.4.2.2 7.4.3.1 The heating, ventilating, and air conditioning systems shall comply with Section 6 of NSI/ASHRAE/IESNA Standard 90.1 2010 with the following modifications and additions, and building products shall comply with one of the following: 1. Energy Policy Act (EPAct) baseline. Products shall comply with the minimum efficiencies addressed in the National Appliance Energy Conservation Act (NAECA), EPAct, and the Energy Independence and Security Act (EISA). 2. Higher Efficiency. Products shall comply with the greater of the ENERGY STAR requirements in Section 7.4.7.3 and the values in Normative Appendix C of ASHRAE Standard 189.1 2011. These requirements supersede the requirements in Tables 6.8.1.A to 6.8.1J of ANSI/ASHRAE/IESNA Standard 90.1 2010. The building project shall comply with Sections 7.4.5.1 of ASHRAE Standard 189.1. Hot Water boilers systems shall incorporate a leak detection system 7.4.3.2 Chilled Water Systems shall incorporate a leak detection system with an alarm or positive displacement meter on water makeup points to prevent fluctuation in the internal system pressure. While on the surface a good idea, building energy requirements in a water standard will lead to confusion in the industry. Additionally, it is my understanding that Standard 90.1 2010 with Addenda is more energy efficient than Standard 189.1. Violates fed preemption for federally covered products and is not allowed if this is a min efficiency standard Most of the requirements in the standard are system/installation requirements; however, this states Hot Water boilers shall incorporate a leak detection system Suggest changing that to Hot Water boilers systems shall incorporate a leak detection Not t cost effective on small chillers. 7.4.3.2 7.4.7.6 Is this required on all sizes? 2. Boiler blowdown the system shall be equipped with a water tempering device which operates only when the discharge temperature to the sanitary system exceeds 140 deg F or recover the heat off the discharge water, when recommended in the manufacturer's instructions. As written, the standard could be misinterpreted to force unnecessary controls on boilers that do not recommend blowdown as part of their regular maintenance.
7.4.8 7.5 High Performance Option 8.2 8.3.2 1. Evaluate thermal energy storage systems to reduce water consumption at the building site and its energy source. 2. Where the utility rates are favorable, the evaluation shall consider: a. Full thermal storage systems. b. Partial thermal storage systems. c. Air cooled with ice thermal storage systems. If this is a minimum standard then this will violate preemption. Unless, you only comply with water requirements (chapter 5?). 8.2 Compliance All appliances and equipment shall comply with Section 8.3, Mandatory Provisions and Section 8.4, Submittals. and those listed below. 1. Section 8.4, Prescriptive Option. 2. Section 8.5, High Performance Option. Many will consider these processes and the standard does not cover processes. Scope should be changed. While the use of thermal storage is beneficial in many instances, no criteria for the level of water savings is listed, rendering this path questionable. Thermal storage systems often use more energy than conventional systems, but this energy is off peak and thus lower cost. Either drop this section or include a water use reduction goal and the path to determine the reduction (.i.e., include source energy water use?). Entire section needs to be reviewed as to proper code ready language. There is also no prescriptive or high performance section listed in this public review draft. 5. Shall use air cooled ice machines that comply with the requirements of the U.S. EPA Energy Star Program for Commercial Ice Machines These can increase cooling demand. Why exclude water cooled that complies with the standard for water use. Closedloop/cooling tower water cooled machines may be best design alternative. 8.3.2 8.4 Submittals Does not specify where to send submittals to. These can increase cooling demand. Why exclude water cooled that complies with the standard for water use. Closed loop/cooling tower water cooled machines may be best design alternative.