Learning Outcomes Upon completion of this training one should be able to: Identify the influence of codes on pump & hydronic design Understand HVAC loads.

Learning Outcomes Upon completion of this training one should be able to: Identify the influence of codes on pump & hydronic design Understand HVAC loads & their impact on equipment selection Compare hydronic HVAC system types & pipe configurations Determine appropriate applications for Magna3 Utilize life cycle cost economics to justify the use of Magna3 in both new and renovated systems Upon completion of this training one should be able to: 1) Identify the influence of codes on pump & hydronic design, 2) Understand HVAC loads & their impact on equipment selection, 3) Compare hydronic HVAC system types & pipe configurations, 4) Determine appropriate applications for the Manga3 pump, 5) Utilize life cycle cost economics to justify the use of the Magna3 in both new and renovated systems

Overview Building energy use & related energy codes
HVAC load calculation HVAC system applications Service hot water applications Magna3 Economics Specifications Pump comparison Obstacles to adoption As we move through the content of this training the we will cover the following topics: Building energy use and related energy codes Building loads HVAC system applications Service hot water applications Magna3 Economics Specifications Pump comparison Obstacles to adoption

Building Energy Use & Related Energy Codes
We have spent a lot of time discussing the codes that influence today’s building design but this of course is only a portion of the designer’s concerns when designing a buildings. In order to select a pump for a application one of the first steps be the design teams is to calculate the HVAC loads within a building.

Why Design Sustainably Conscious Buildings?
In 2010, the DOE approximated that U.S. buildings accounted for: 41% of total energy use 74% of electric consumption 40% of CO2 emissions 12% of potable water use By 2025, it is projected that buildings will be the largest consumers of global energy – greater than transportation and industry combined. The building construction industry has seen a significant change in priority for selection criteria for their design. The largest change is the fact that owners are asking for more energy conscious designs rather than allowing first costs be the only priority. This change can be attributed to greater understanding of limited energy sources resulting in increased energy rates and ultimately larger utility costs over the life of the building. The DOE (Department of Energy) approximates that U.S. buildings account for: 41% of total energy use, 74% of electric consumption, 40% of CO2 emissions, 12% of potable water use.

Why Design Sustainably Conscious Buildings?
2012 Department of Energy, Building Energy Data Book As displayed in this chart, industrial, commercial, and residential buildings consume far more energy than the automobiles on the roads . This makes it easily arguable that the building construction industry has the opportunity to make a tremendous impact – far greater than the automotive industry. A message that has not been effectively communicated by the media.

Commercial Energy End-Use
2006 U.S. Energy Information Administration (EIA) Energy is consumed in the many functions of a commercial building. HVAC systems, the light blue segments, total 32% of the overall energy use. Considering that pumps and fans, depending on the type of HVAC system employed, demand the largest portion of the energy consumed by the system therefore it is clear that improvements in pump and fan efficiencies can have a significant impact on energy demand.

Future Building Market
Existing U.S. building stock is ~275 billion ft2 Over next 30 years: 52 billion ft2 will be demolished 150 billion ft2 will be remodeled 150 billion ft2 will be new construction By 2035, approximately 75% of U.S. building stock will be new or renovated Energy Information Administration, Courtesy of Architecture 2030 Energy and water use by new buildings should not be the only focus of the construction industry since it there is a significant opportunity in the renovation market because of the significant stock (~275 billion ft2)of existing buildings. Over next 30 years: 52 billion ft2 of buildings will be demolished, 150 billion ft2 remodeled, and 150 billion ft2 newly constructed. By 2035, approximately 75% of U.S. building stock will be new or renovated.

Energy Codes & Standards
International Code Series – Jurisdictions Adopt Energy consciousness has become a societal priority. This can be attributed the green movement as well as the fact that energy production is nearing capacity of the existing plants and infrastructure resulting in increased pricing. Energy codes and standards are being developed and updated to help address the need to decrease energy use. The most commonly adopted and enforced energy code is the International Energy Conservation Code (IECC). This is adopted at the local jurisdiction level. Another code that has been newly published by the International Code council and is beginning to be adopted is the International Green Construction Code (IgCC).

Energy Codes & Standards
ASHRAE Standards – Designer Reference Although the International Code Series (IECC and IgCC) are the most commonly adopted codes, designers typically use the ASHRAE published design standards to guide their designs. This is acceptable as the IECC states that ASHRAE Standard 90.1 is an alternate compliance path and IgCC states that ASHRAE Standard is an alternate compliance path.

Energy Codes - Commercial
ANSI/ASHRAE/IES Standard Significant changes compared with 2007 Continuous maintenance publishing every 3 years ~30% increase in building performance from 2004 version Consensus based document Cost justification required Only addresses energy ANSI/ASHRAE/IES Standard is much different than the 2007 version of the standard with an decrease in energy use by approximately 30% compared to the 2004 version. This standard is consensus based document meaning that agreement must be found before allowing change and cost justification is required (ability for the energy saving measure to pay for itself over time).

Energy Codes - Commercial
ANSI/ASHRAE/USGBC/IES Standard Builds on ASHRAE Standard 90.1 Does not require cost justification Addresses design & operation Site Sustainability Water use Efficiency Energy Efficiency Indoor Environmental Quality Environmental Impact Construction & Operation ANSI/ASHRAE/USGBC/IES Standard builds on the requirements of 90.1 but is different in that it does not require cost justification and it addresses more than just energy related items. Note that the title is high performance therefore includes topics such as water use, Indoor Environmental Quality, and operation.

ASHRAE Standard Does not specifically address pumps or hydronic systems If criteria is not defined in ASHRAE Standard 189.1, then ASHRAE Standard 90.1 is the referenced minimum code Includes requirements for the measurement of energy consumption using meters Enhances the potential for building audits When looking at the content of ASHRAE Standard you will not find the topic of pumps or hydronic systems. Anything that is not addressed in should use 90.1 as the minimum code. One influential item in to the content of this training is the fact that to comply meter must be used to measure energy consumption. This is an important component because it impacts the long term monitoring of performance of buildings and enhances the opportunity for building auditing.

Auditing Audit levels I, II, III defined by ASHRAE
Benchmarking – Energy Star portfolio Meter requirement in ASHRAE Standard or LEED LEED - 3 points from Performance Measurement Push for benchmarking and auditing San Francisco New York Auditing is gaining prominence in the building industry because operation is where most expense is incurred over the life of a building. ASHRAE defines three levels of energy audits. The most simplistic audit is Level I and the most thorough as well as requiring the greatest initial investment is Level III. The auditing procedure allows systems and / or equipment to be identified that are operating at a lower efficiency then first installed and tested. The lower efficiencies can be a result of many different things such as dirt build up or incorrect settings. The advantage of an audit is that whatever the cause it can be identified and corrected without having to experience failure or extended system inefficiency. Benchmarking is the term used to define the baseline for which the systems is compared in the future. This benchmarking can be tracked in a simplistic fashion monitoring whole building utility consumption using the U.S. EPA (Environmental Protection Agency) Energy Star Portfolio or it can be more complex and detailed using the meters for specific pieces of equipment or systems. The installation of meters is required by both and LEED. Legislation is also becoming a driving force for auditing. In San Francisco, nonresidential buildings will be required to complete auditing, benchmarking, and reporting of findings, no less than every five years. New York has similar legislation that entails similar benchmarking, energy auditing, and retro-commissioning measures for private/existing buildings greater than 50,000 sq ft, and public buildings greater than 10,000 sq ft. This is a trend that is becoming more popular in cities policies as well as being required by power utility companies.

Energy Star Portfolio Manager
Online energy management tool created by U.S. EPA Tracks and assesses energy and water consumption across a portfolio of buildings Used by more than 200,000 commercial Advantages to a building owner: Benchmark energy use Determine energy-use intensity (kBTU/ft2) Track changes in energy and water use over Compare against national sample of similar buildings Energy Star’s Portfolio Manager is an online energy management tool created by the United States Environmental Protection Agency (EPA). This online tool is used by more than 200,000 commercial buildings to track their energy and water use, and to make strategic decisions in regard to reducing their consumption. The advantages of using Energy Star’s Portfolio Manager include: benchmark of energy use, determine energy-use intensity (kBTU/ft2), track changes in energy and water use over time, and compare against national sample of similar buildings.

ASHRAE Standard 90.1-2010 Pump Applications
Since does not address pump applications, ASHRAE Standard is the standard that should be referenced for design. The following slides will introduce the standard in general as wellas the different sections of the code related to pumps and hydronic systems.

ASHRAE Standard 90.1-2010 Scope
Applies to all buildings New construction Additions to existing facilities New & replacement equipment / components Excludes residential buildings <3 stories in height Defines the minimum efficiency requirements ASHRAE Standard applies to all buildings (different from 2007 version of the code). This includes new construction, additions to existing facilities, and new and equipment or components, and residential buildings when greater then 3 stories in height. The key to implementation of this standard is understanding that it defines the minimum efficiency requirements. This means that a building that only meets these minimums is as inefficient as possibly acceptable. A building may be designed above these minimums at the discretion of the owner and designer.

ASHRAE Standard 90.1-2010 Structure
Multiple sections: Envelope, HVAC, Service Water Heating, Power, Lighting, & Other Equipment Mandatory Provisions Prescriptive Path or Energy Cost Budget (ECB) Appendices (Normative) A Assembly U-, C-, and F-Factor Determination B Building Envelope Climate Criteria C Envelope Trade-Off Methodology D Climate Data ASHRAE Standard 90.1 is broken into multiple sections: Envelope, HVAC, Service Water Heating, Power, Lighting, Other Equipment. Each of these sections are then split into mandatory provisions and prescriptive path to attain compliance. The mandatory requirements must be complied with no mater the manner of showing compliance. The prescriptive path is the simpler and more commonly used method of proving compliance since it requires only that the designer meet the defined criteria per the standard whereas the ECB requires energy modeling (more time and effort) to display compliance. There are also appendices that are used for reference and provide additional information such as the weather tables.

ASHRAE Standard 90.1-2010 Section 6
Section 6 HVAC 6.1 General 6.2 Definition of Compliance 6.4 Mandatory Provisions 6.3 Simplified Approach 6.5 Prescriptive Path Section 11 ECB 6.7 Submittals Section 6 HVAC is split into seven subsections: 6.1 General, 6.2 Definitions of Compliance, 6.3 Simplified Approach, 6.4 Mandatory Requirements, 6.5 Prescriptive Requirements, & 6.7 Submittals. Not all the subsections need to be complied with rather one of the indicated paths must be followed to ensure compliance. Ultimately all the paths will require the same maximum level of energy consumption but some paths are limited to specific types/sizes of HVAC systems

Section 6 HVAC 6.1 General 6.2 Definition of Compliance 6.4 Mandatory Provisions 6.3 Simplified Approach 6.5 Prescriptive Path Section 11 ECB 6.7 Submittals The path including 6.3 the Simplified Approach is the easiest method of showing compliance but it is limited to small buildings with very basic HVAC systems. Hydronic heating and cooling systems are included in this path therefore eliminating it from the discussion for this presentation.

Section 6 HVAC 6.1 General 6.2 Definition of Compliance 6.4 Mandatory Provisions 6.3 Simplified Approach 6.5 Prescriptive Path Section 11 ECB 6.7 Submittals Besides the 7 subsections of Chapter 6 an alternate compliance path includes Section 11 ECB, Energy Cost Budget. This path is used when compliance is not possible by one of the other paths but the building energy use is projected to be less than or equal to the defined minimums using one of the other paths. This path is rarely used because it is more time consuming, complicated, and expensive but is needed for some of the more complex buildings being built today.

Section 6 HVAC 6.1 General 6.2 Definition of Compliance 6.4 Mandatory Provisions 6.3 Simplified Approach 6.5 Prescriptive Path Section 11 ECB 6.7 Submittals The most commonly used path for compliance is the one highlighted here that includes 6.4 Mandatory Provisions & 6.5 Prescriptive Path. This path allows the designer to follow the compliance procedure in a clearly defined method that identifies all the minimums for compliance. This path, it requirements, and how it applied to hydronic systems are discussed in much more detail in the following slides. We will begin with the requirements of subsection 6.4 since the subsections 6.1 and 6.2 are more administrative in content.

ASHRAE Standard 90.1-2010 Mandatory
Section 6.4 Primary topics include efficiencies and controls Section Equipment Efficiencies No specified efficiencies for pumps Pump efficiencies are being developed No defined criteria for pump selection Section 6.4 focuses on efficiencies and controls. Tables are provided in the standard that defines the minimum efficiencies for many different types of HVAC equipment. No minimum efficiencies are defined for items not contained in the tables - pumps are one item not included. Currently effort is being put towards the development of minimum pump efficiencies.

Section Calculations Design load calculations for heating and cooling Pump head calculation for the purpose of pump sizing Determined in accordance with generally accepted engineering standards and handbooks The first of the mandatory criteria is to require calculations of the heating & cooling loads as well as the pump head. Calculations are important to include in an energy standard because over-sizing equipment has detrimental effects on energy consumption. The standard does not say that the system design has to be the same as load calculated but allows the designer to use their judgment. The calculation requirement is included to discourage sizing systems based on rules of thumb – changes in internal loads and construction techniques/materials have made it so that these old rules of thumb result in significantly oversized systems. It is expected that a designer with the load calculation results will be more inclined to use these more accurate values than grossly oversize a system.

6.4.3 Controls 6.4.4 HVAC System Construction and Insulation The next two sections Controls and HVAC System Construction and Insulation although important do not specifically address hydronic or pumping systems. This is the last of the mandatory requirements.

ASHRAE Standard 90.1-2010 Prescriptive Path
6.5.1 Economizers Water Economizer Required for specific OA temperature and humidity Maximum Pressure Drop < 15’ head for precooling coils and water to water heat exchanger ≥ 15’ head secondary loop required so this pressure drop is not seen by the circulating pump Section 6.5 begins the requirements of the prescriptive path compliance. The subsections that relate to hydronic topics include Water Economizer and the related Maximum Pressure Drop. ASHRAE Standard 90.1 requires the use of a water economizer when outside conditions are within specific parameters for projects that utilize a water cooled chiller. These subsections of ASHRAE Standard 90.1 are not necessarily the most obvious so let’s begin by explaining what a water economizer is and once we have that covered we will come back to requirements defined by the standard. To do this let’s first consider the piping configuration of a water cooled chiller.

Water Cooled Chiller Piping
Supply Secondary Pump Cooling Tower Primary Pump Loads Head Pressure Control Valve Evaporator Return Condenser Air Separator And Exp Tank Condenser Pump Chiller Sediment and Air Separator A water cooled chiller requires that there be a heat rejecting piece of equipment located outdoors. In this case it is the cooling tower. This piece of equipment is connected to the chiller’s condenser creating the condenser water loop. Two additional piping loops exist inside the building to distribute the chilled water to the space loads such as coils. One of these loops is the primary loop and the other is the secondary loop. The details of this piping and its configuration is important so that we can see the difference compared to piping system that incorporates a water economizer.

Water Cooled Chiller w/ Water Economizer
Supply Secondary Pump Cooling Tower Primary Pump Loads Head Pressure Control Valve Valve Position: Open Evaporator Return Condenser Sediment Separator Air Separator And Exp Tank Condenser Pump Chiller Chiller Operation Economizer Condenser Pump Heat Exchanger With a water economizer an additional piping loop is added to the systems (shown here in black). If we ignore this new loop, the piping is matches the previous slide. The system is not altered when the OA temperature are hot and cooling demand is high – the chiller and cooling tower operate and the economizer loop is ignored.

Supply Secondary Pump Cooling Tower Primary Pump Loads Valve Position: Closed Evaporator Sediment Separator Return Condenser Air Separator And Exp Tank Condenser Pump Chiller Economizer Mode Economizer Condenser Pump Heat Exchanger When the OA temperatures are temperate (below 50 degrees dry bulb and 45 degrees wet bulb), the work done by the chiller can be decreased as a result of free cooling because the cooling tower’s evaporative cooling can achieve low enough water temperatures to reduce the entering water temperature into the chiller. This is considered a water economizer. In this scenario, two way control valve closes directing the water through the heat exchanger coling the return water temperature going to the chiller – represented by the purple piping. This ultimately allows the chiller to work less and therefore decrease energy consumption. Note there are different types of economizer piping configurations – this configuration is referred to as water-precooling. The advantages of this configuration is it protects the equipment from the open condenser water loop and for a pump manufacturer, it requires an additional pump. Now that we understand a water economizer and how it impacts the piping configuration we can discuss the implication of ASHRAE Standard 90.1.

6.5.1 Economizers Water Economizer Required for specific OA temperature and humidity Maximum Pressure Drop Feet of head for water to water heat exchanger < 15’ acceptable ≥ 15’ head secondary loop required so this pressure drop is not seen by the circulating pump The fact that the economizer is required is straight forward but the maximum pressure drop requirements need some additional explanation. The head or pressure drop associated with the heat exchanger must not exceed 15’ of water or a secondary loop must be created. The purpose of this secondary loop is to ensure that the pressure drop is not seen by the pump during normal cooling operation.

Supply Secondary Pump Cooling Tower Primary Pump Loads Valve Position: Closed Evaporator Sediment Separator Return Condenser Air Separator And Exp Tank Condenser Pump Chiller Economizer Mode Economizer Condenser Pump Economizer Chilled Water Pump Heat Exchanger The addition of a secondary loop for the configuration of piping discussed earlier simply means the addition of a pump to the loop that connects to the heat exchanger to the chilled water return (Click). The addition of this pump allows the heat exchanger loop pressure drop to be disregarded in the calculations to size the chilled water pumps used in normal operation. This is important to limit the potential energy losses of this system configuration while taking advantage of the energy savings of the economizer cycle.

6.5.2 Simultaneous Heating and Cooling Hydronic Coils Cannot cool water previously heated Cannot heat water previously cooled Defines change over temperature / time Prohibits 3 pipe system configuration Common return pipe Section 6.5 Simultaneous Heating and Cooling includes requirements for hydronic coils that prevents the cooling of previously heated water and the heating of water that had been previously cooled. It also defines the allowable hydronic water change over temperature or time for different pipe configurations such as two pipe. ASHRAE Standard 90.1 also prohibits the installation of three pipe systems – hot water and chilled water supply pipe utilizing a common return pipe because the energy required to reheat or re-cool the common return water.

6.5.4 Hydronic System Design & Control Hydronic Variable Flow System Total pump system power > 10hp & control valves designed to modulate flow based on load Design variable fluid flow - reduce pump flow rate to ≤ 50% design flow rate Control shall be based on flow or min. differential pressure Hydronic System Design & Control is addressed in Section This section defines when variable flow is required as well as the operation of a variable flow system. When total pump system power (sum of all the motor nameplate horsepower of pumps within the piping system i.e. chilled water or hot water) is greater than 10hp & the systems contains control valves designed to modulate flow based on load the following criteria must be met: Design variable fluid flow reducing the pump flow rate to less than or equal to 50% design flow rate and control must be based on flow or min. differential pressure.

Hydronic Variable Flow System (continued) CHW pump in variable flow system > 5hp, controls are required that will result in pump motor demand of ≤ 30% of design wattage at 50% of design water flow Acceptable Operating Range Individual chilled water pumps in variable flow system greater than 5hp are required to have controls that will result in pump motor demand that is no more than 30% of design power at 50% of design water flow which is best achieved by using a variable speed drive.

Pump Isolation More than one Boiler/Chiller: need to be able to automatically reduce flow when a boiler or chiller is off Chilled & Hot Water Temperature Reset Controls Required when >300,000 BTUh system capacity unless variable flow is used to reduce pumping energy Section Pump Isolation states that when there is more than one Boiler or Chiller the hydronic system needs to be able to automatically reduce flow when a boiler or chiller is off. Section requires chilled & hot water temperature reset controls when the system capacity exceeds 300,000 BTUh unless variable flow is used to reduce pumping energy

Hydronic Heat Pump & Water Cooled AC Total pump system power > 5hp Controls to result in pump motor demand of not more than 30% of design wattage at 50% of design water flow. Based on variable speed drives Total pumps system power is again addressed, recall the prior graphic, when the total pump system power exceeds 5hp in a hydronic heat pump and water cooled air conditioning systems.

Pipe Sizing Variable flow allows smaller pipe sizes Pipe sizing criteria is outline in Table This is new to the 2010 version of ASHRAE Standard 90.1 although it has been referenced in the ASHRAE handbook for quite some time. Because it is now included in the energy code it has much more influence on the design process. Because not all jurisdictions have made the transition to the 2010 version of the code and not all designers are current with the changes in code content it is an opportunity for the sales representatives to help share and reinforce this information.

6.5.4.5 Pipe Sizing Variable flow allows smaller pipe sizes
Let’s walk through what this chart means and how it impacts the design of a hydronic system. (Click) The system must be first identified as a variable flow/speed system or ‘other’ which would include constant flow system to determine the column reference. (Click) The next step in the column selection is to determine the number of hours per year the system will operate. In a location like Houston the chilled water system would be likely operate I excess of 4,400 per year while the hot water system is likely to be less than 2000 hours per year. Let’s concentrate on a system that operates for fewer hours per year to allow us to see the table more clearly.

Pipe Sizing System Criteria Operating hours: 1800 hrs/yr
Max Flow: 200 GPM Constant Flow System Pipe size: 4” Pipe Head Loss: 2.5’/100’ Velocity: 5.5 fps Variable Flow System Pipe Size: 3” Pipe Head Loss: 9’/100’ Velocity: 9 fps (Click) If comparing the design of a constant flow system and a variable flow system at the performance values of 1800 hours per year and 200 gallons per minute maximum flow, (click) the table requires a 4” pipe for constant flow and only a 3” pipe for variable flow. It is important to note that the pipe sizes are smaller in variable flow/variable speed systems because it is expected that these systems will operate at full load only a small percentage of the time therefore the energy to overcome the increased head is less compared to the cost of increased pipe size. Remember that ASHRAE Standard 90.1 only includes energy efficiency measures that are cost justifiable. (Click) It is also important to recognize the sizing criteria as far as head and velocity are different than the values traditionally used by design engineers – 4’/100’ and 10 fps maximum. Another thing to recognize is that this table is based on steel pipe pressure drops and adjustments can be made for other piping materials per the approval of the authority having jurisdiction.

ASHRAE Standard 90.1-2010 Submittals
System Balancing Hydronic System Balancing 1st minimize throttling losses 2nd trim impeller or adjust pump speed except when pump ≤ 10hp or throttling loss ≤ 5% of nameplate horsepower above that required if the impeller were trimmed Section 6.7 defines the submittal requirements at project close out. Balancing of the hydronic system is included in this section. A hydronic system shall be balanced first by minimizing the throttling losses and secondly trimming the impeller. This topics will be cover in greater depth later in the training.

Section 7 – Service (domestic) Water Heating Circulating Pump Controls Pumps are not limited to applications in HVAC systems. They are also routinely used in domestic (service) hot water systems as recirculating pumps. ASHRAE Standard 90.1 Section 7 addresses the controls that are needed on circulating pumps. Note that ASHRAE Standard 90.1 references this service hot water pump as a circulating pump which is inconsistent with most pump manufactures nomenclature as well as the definitions in Section 3 of the Standard. The common terminology is recirculating pumps for domestic water systems and circulating water pumps in heating hot water systems.

Building Rating / Certification
Building codes and standards are just one influence on the design of energy and water conscious buildings. Another important factor is the impact of the different building rating and certification systems.

Building Rating / Certification
Typically owner driven – NOT code Domestic Building Rating Systems LEED Energy Star Building EQ Green Globes International Building Rating System BREEAM Pull the design market progressive compared to the push of the building codes Building rating and certification systems are different than codes in the fact that they are applied at the request of the owner. There are many different building rating systems: LEED, Energy Star, Green Globes, Building EQ, and BREEAM. Each of these rating systems have their own criteria and design requirements but have one thing in common – they encourage more energy conscious and sustainably focused design. The energy codes define minimum – how bad a building can be and still be constructed while the building rating systems encourage building owners to exceed these minimums and invest better design. This is important to the design market because owners ultimately control the budget and designing better systems on their request is much easier then trying to convince them to invest in sustainable design. The following few slides will discuss the certification programs seen most commonly in North America.

Leadership in Energy and Environmental Design (LEED)™
Developed by the U.S. Green Building Council Rating system for buildings Sustainable site development Water savings Energy efficiency Material selection Indoor environmental quality Points / Credit System – Platinum, Gold, Silver, & Certified Third-party verification Accredited Professionals LEED, Leadership in energy and Environmental Design is likely the certification program that the general public is most familiar with. LEED was developed by the US Green Building Council as one of the first certification programs and did the best job marketing themselves beyond the design community. The criteria considered for certification is beyond energy use as it also looks at factors such as sustainable site development, water savings, energy efficiency, material selection, and indoor environmental quality. The certification levels of platinum, gold, silver, and certified are based on a point system and must have both accredited professionals and third party verification as part of the process.

Energy Star Developed by the U.S. Environmental Protection Agency
Calculations are based on source energy Label based on building energy us 50 indicates average energy performance 75 or better indicates top performance Energy Star was first introduced at about the same time as LEED but did not get marketed to the same extent therefore is not as familiar. This rating system is significantly different because it is based on building energy consumption rather than on the design process. Being that energy is the focus, the source energy: electric from the grid, electric from wind or solar, or gas, is an important variable in this certification process. Not only does the source of energy matter but also amount energy consumed by the building. Energy consumption is monitored and compared to similar buildings. Based on this comparison the building being certified is qualified for an Energy Star rating if it consumes less energy then 75% of its peer buildings. This peer set is constantly changing because the technology and opportunity for more efficient buildings is improving with time.

Building Energy Quotient (bEQ)
Developed by ASHRAE Newest of the rating systems Label based on building energy use Design performance Operation performance Requires an ASHRAE-certified Building Energy Assessment Professional The newest of the rating systems is the Building Energy Quotient by ASHRAE. This rating systems looks at both the design and operating performance of a building therefore combining attributes of LEED and Energy Star. It does require that a ASHRAE-certified Building Energy Assessment Professional be involved in the process. These are the three primary certification systems used in the U.S. but one that us gaining ground in the US and is most commonly used in Canada is Green Globes.

Green Globes Developed by Energy and Environment Canada
Third-party verification Four levels of ratings Green Globes was developed by and is administered by Energy and Environment Canada. Similar to the other rating systems is composed of multiple levels and required third-party verification. It like LEED looks at more than just energy use. The categories of compliance include: energy, indoor environment, site, water, resources, emissions, project/environmental management. All of the rating systems discussed are good for the industry as they bring an awareness and consciousness to energy use, efficiency, and sustainable design. Each owner often has a preference as to which if any of the rating systems should be applied to their project but ultimately the fact that these rating systems exist make the conversation related to sustainable design easier with our building owners.

HVAC Load Calculations
We have spent a lot of time discussing the codes and building certification systems that influence today’s building design but this is only a portion of the designer’s concerns when designing a buildings. In order to select a pump for an application, one of the first steps taken by the design team should be to calculate the HVAC loads within a building.

Building Loads Heating and cooling load calculations performed as required per ASHRAE Standard 90.1 Section 6 HVAC Important to minimize over-sizing and maximizing efficiency As previously discussed calculating these loads is required per the energy code because it is important to both minimizing over-sizing and maximizing efficiency.

Purpose of Loads Load used to select system and size equipment
Size of the system limits equipment options Example: Small water cooled chillers not readily available Other factors also influence the system selection: Owner priorities Space availability Acoustics Exterior equipment restrictions Etc. The purpose of conducting a load calculation is to ultimately select an appropriate HVAC system and properly size equipment. The build load helps narrow down the practical system options for example a building with a small cooling load would like not use a water cooled chiller system since small water cooled chillers are not readily available in the U.S. It is important to recognize that building loads are only one of many factors considered in the selection of a system. Other items consider include: Owner priorities, space availability, acoustics, exterior equipment restrictions, etc.

Load Calculation Software often used to perform the analysis because of the complexity Goal of the calculation is to establish the peak load experienced by the building Complexity is a result of the many variables that must be considered Load calculations are typically conducted using software because of the complexity of the analysis. Some of the more common software used include: Trane TRACE 700, Carrier HAP, and elite. The goal of performing the calculation is to determine the peak load experienced by the building. The complexity enters the equation in that there are MANY variables that must be considered.

Load Calculation Heating Cooling
The load calculations are performed both for the heating and the cooling load.

Load Calculations Items accounted for in a peak load calculation
Weather conditions Envelope (walls, floors, windows, roof, etc.) Thermostat set point (summer vs. winter) Items accounted for in a peak load calculation include: weather conditions, building construction more specifically the envelope (walls, floors, windows, roof, etc.), and the internal thermostat set point (summer vs. winter). These factors are obvious. If the building is located in a southern hot climate the cooling load will far exceed the heating peak load. Better building construction minimizes the effect of heat transfer. In addition to the quality of the construction and materials used the mass of the components will also effect the peak – walls with significant mass i.e. concrete will delay the building peak loads to not match the exterior temperature peaks because of the delay of heat transfer. This only one of man complexities in the design. We should not forget that our building occupant also plays a important role in the peak load calculation as they determine the thermostat set points.

Climate Zones Marine (C) Moist (A) Dry (B)
Using climate zones is a common method of distinguishing whether certain energy saving features are applicable based exterior weather conditions. These climate zones are referenced by most energy codes. As graphically represented here there are 8 primary climate zone in the U.S. with 1 being the hottest and 8 being coolest. As I am sure we are all familiar, temperature is not everything when we discuss weather i.e. those that claim that 110 degrees F is not that hot because it is dry heat. This climate zone map distinguishes climates beyond temperature by labeling regions as Marine (c), Dry (b), and Moist (a) acknowledging that humidity does play a factor.

Cooling Loads Loads considered specific to cooling
Internal loads (people, equipment, lights, plug loads) Time of day and orientation (sun position) There are some elements that are only considered when conducting a cooling load calculation. These cooling only influences include internal loads and effects of sun position. Internal loads include heat gain that is attributed to people, equipment, lights, and plug loads within the space. The sun position is important as we know that he sun position will influence the amount of radiant heat gain depending on the building orientation and quantity of windows.

Heating Loads Heating peak load does not include the heat gain from sun and internal loads Worst case for heating occurs at night No sun, people, or equipment loads The internal heat gain and solar radiant loads are only considered for the cooling load calculation because in a load calculation we are determining the peak or the worst case situation (this does not hold true if we were conducting an energy consumption analysis). Since the worst case for heat will occur at night there will be no solar radiant loads and for many buildings it can be assumed that people leave and equipment is turned off at night. If we were to include the theses heat gains in the heating peak load calculation it would result in a reduced heating load that does not does not accurately represent the peak.

Building Examples Multi-use Facility Medical Office Building Hospital
4 Multi-use Facility Medical Office Building Hospital Campus w/ central plant 1 2 3 Applying these heating and cooling load concepts to example buildings will allow us to better explain the building HVAC load calculation process. To do this we need to first introduce the (3) building examples used for this training. These buildings include a small multi-use facility, a medium sized medical office building, and a large hospital. (Click). We will also consider a forth example for training purposes of all three of these buildings being tried together and served by a central plant producing hot and chilled water. This configuration will be referred to as a campus.

Multi-use Facility Occupancy – 140 persons
6 a.m. – 6 p.m. Monday - Friday Building Characteristics Single story 20,000 square feet (250’ x 80’) Standard construction The smallest of the building is the multi-use facility. This building is a single story 20,000 square foot building with 140 occupants. The occupied hours are expanded to included 12 hours per day Monday through Friday beginning at 6 am.

Medical Office Building
Occupancy – 400 persons 8 a.m. – 5 p.m. Monday - Friday Building Characteristics Three stories 40,000 square feet (200’ x 200’)/floor Standard construction The next of the example buildings is the medical office building. This building also of modeled using standard construction is thee stories in height each having an area of 40,000 square feet. The building will be occupied by 400 people at the peak and have the operational hours of 8 to 5 Monday through Friday.

Hospital Occupancy – Patient areas: 24 hours per day
Office areas: 8 a.m.– 5 p.m. Monday-Friday Building Characteristics: Four story with basement 140,000 square feet per floor Standard construction The hospital is the largest of the example buildings. The facility will be split into different occupancies – the patient area that will be used 24 hours a day 7 days a week and the office/support areas that will occupied during traditional business hours – 8-5 / 5 days a week. The building is fours stories high with a basement. Each floor will have an area of 140,000 square feet. For the purposes of modeling the envelope will be considered standard construction per the defaults eQUEST version 3.64 (Department of Energy Free software).

Climate Zones Anchorage Chicago Houston
The building are compared not only to one another for this training but we also will look at how the weather condition will influence the loads. For this weather analysis three different locations have been selected – 1) Hot, Climate Zone 2, Houston; 2) Moderate, Climate Zone 5; Chicago and 3) Cold, Climate Zone 7, Anchorage.

Peak Loads Cooling Heating
Using calculation software the peak loads for each of the buildings in each of the three locations have been conducted. Heating is represented by red and cooling is represented as blue in the graphs. Note that the y-axis units change in each of the charts (peak off 600 MBH for multi use compared to 12,000 MBH for the hospital). The hospital is expected to have the largest load and the multi use facility the smallest simply as a result of facility size. It is also not surprising to see the controlling peaks loads change from cooling to heating based on the climate zone. We would expect the heating load to be larger in Anchorage than in Houston.

Multi Use 3% 26% 37% 10% 47% 32% One other item that is worth noting is the change in proportion of heating and cooling loads based on location. For example the peak heating and cooling loads for the multi use facility are closer to equal than for the hospital facility. This can be attributed to the fact that in smaller buildings the envelope load typically has a larger impact on the load compared to larger buildings were internal loads typically control.

Operational Load Peak is a worst case moment in time
Many variable change even during a peak day Change in outside temp from morning to night Fluctuation in occupancy Equipment/Lighting loads are not consistent Changes in thermostat set points It is important to discuss the difference between the peak load used to select the system and size the equipment and the actual operational loads. These values are quiet different in that the peak is a worst case moment in time for a buildings load while the operational load is the load that changes based on the many variables considered in the load - change in outside temp from morning to night, fluctuation in occupancy, equipment/Lighting loads are not consistent, changes in thermostat set points due to occupant preferences, etc.

Simultaneous Heating & Cooling
Operation vs Peak Design Cooling Peak 15% Over-sized Cooling Design Heating Peak 25% Over-sized Heating Simultaneous Heating & Cooling This graphics is the actual data collected from a facility showing the difference between peak design loads and operational loads. The deign cooling peak for which the equipment is sized is represented by the blue dot at the top right and the heating peak is represented by the red dot at the top left. The blue and red triangles represent the actual heating and cooling demands. As one can see the actual demand never reaches the design peak and much of the time the peak load for which the equipment is selected far exceeds the demand. Another thing to note from this graph is at an ambient temperature of approximately 45 degrees plus or minus 10 degrees, there is both the need for heating and cooling depending on the space likely due to envelope exposure and sun position at a load that dose not exceed 10% of the heating or cooling design peak.

Over-sizing Result of conservative initial assumptions
Exaggerated by the idea that bigger is better Belief that safety factors is needed to protect themselves from under-sizing the equipment Select components that are the next size larger to be ‘safe’ when between sizes Bigger is NOT better in HVAC design! As just presented - the loads did not ever reach the design conditions therefore it could be said that the system is over-sized. The over-sizing issue can be attributed to many factors. Engineers are known to be risk adverse therefore initial assumptions are typically conservative. Many designers have not let go of the idea that bigger is better therefore this already conservative and oversized design is further exaggerated. Another common misnomer is that it is a good idea to apply a safety factor to their design values to protect themselves from inadvertently under sizing a systems or its components. Even when a safety factor is not specifically applied to calculated values it is common practice for a designer to select equipment that is the next size larger to be safe when between standard equipment size increments.

Conservative Design Justification for over-sizing:
Systems may not be installed per the plans Weather extremes will exceed the design values Changes in number occupants, thermostat set points, equipment/lights, etc. from that initially defined Changes in operation i.e. control settings and/or sequenced altered from that in the specification Changes in operational characteristics as a result of maintenance (or lack there of) and age of the system There are multiple ways that designers justify over-sizing even though in many cases it sacrifices optimum performance and efficiency. Systems are not always installed per the design plans therefore the reason construction as-builts exist. These changes occur during construction due to conflicts or issues that were not anticipated in the original design and the designers try to compensate for this with conservative design. It is also recognized that the temperatures taken from ASHRAE weather table are averages and the actual extremes will exceed the design values some of the time. What is often forgotten is that if the external temperature extremes exceed the design values it does not deem the space unoccupiable but rather the thermostat temperature may not be able to be temporarily maintained - in most situations this is considered acceptable. Variations in design assumptions such as internal loads, thermostat set points, and operational characteristics are also items that are outside the designers control and conservative over-sized system attempt to compensate for but at some point the number of safeties applied are equivalent to wearing a belt and suspenders – can we afford to design if all ‘what if’ must be accounted for?

Poor Design Practice Rules of thumb Time / budget
Conservative design occurs by the best designers that are thorough but then there is also the other situations where over-sizing occurs due to poor design practice. Rules of Thumb are still used in out industry even though ASHRAE Standard 90.1 requires that load calculations be performed. This incomplete design practice of performing more precise calculations is typically employed because of limited time or the budget. It should be clarified that with every project there are a number of parameters that need to be balanced and one is the owner and their interests – an owner that is simply building for quick resale versus a long term owner that will occupy the building have very different priorities. It is important to acknowledge that design is not always done correctly or with sustainable design in mind but this training will instead concentrate on helping good designers and owners do better then they are today with building more efficient buildings.

Better Design Designers do not always look at the part load operation when selecting and specifying equipment Redundancy is required on some projects (N+1) May be good practice when not required Revised Cooling Design Peak Revised Heating Design Peak Thinking back to the prior graphic showing operation versus peak load calculated even if the peak had been reduced to the location of the bold red and blue line, a good portion of the time the system would operate at only part of this peak load. Although it appears obvious that designers should look at not only the peak load but also part load values when selecting systems and sizing equipment, it is certainly not always employed due to time and budget constraints as well as sometimes the understanding of the system by the designer. If the system configuration were considered more closely, it becomes clear that using multiple pieces of equipment in lieu of a single large piece of equipment is an optimal solution. The most efficiency piece of equipment is one that is shut off which can occur when loads are small and multiple pieces of equipment are utilized. Some projects require redundancy referred to as N+1 such as data centers, hospitals, and laboratories. But using multiple pieces of equipment such as pumps can also be applied to non-critical applications allowing systems to be sized more appropriately for part load applications while also providing backup in the case one of the pieces of equipment fail.

Impact of over-sizing Pumps must meet operational loads therefore affecting the position on the pump curve compared to the original (over- sized) selection Affects the pump efficiency This over-sizing effects our pump selection because the pump must meet operational loads therefore effecting the position on the pump curve compared to the original (over-sized) selection. This will in turn effect the pump and ultimately the system efficiency.

Learning Outcomes Upon completion of this training one should be able to: Identify the influence of codes on pump & hydronic design Understand HVAC loads.

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Learning Outcomes Upon completion of this training one should be able to: Identify the influence of codes on pump & hydronic design Understand HVAC loads.

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Presentation on theme: "Learning Outcomes Upon completion of this training one should be able to: Identify the influence of codes on pump & hydronic design Understand HVAC loads."— Presentation transcript:

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