John Swift, Jr., PE, LEED, CEM Principal – Cannon Design, Boston, MA

Smart Water Use:

Developing an ASHRAE Water Standard

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Learning Objectives: 1. Describe the purpose of SPC 191 and the opportunities for water efficiency

in building HVAC systems.

2. Describe how interactions with non-HVAC systems are affected.

3. Explain the water-energy nexus.

4. Describe how Standard 191 applies to other standards like 189.1 and how it

may be applied on future building design projects.

Session Agenda: 1. Why develop an ASHRAE water standard?

2. Overview of Proposed ASHRAE Standard 191 on Water Efficiency

3. Comparison of Existing Water Standards and Codes

4. Design Considerations

5. Case Studies

6. Questions?

Session Agenda: 1. Why develop an ASHRAE water standard?

2. Overview of Proposed ASHRAE Standard 191 on Water Efficiency

3. Comparison of Existing Water Standards and Codes

4. Design Considerations

5. Case Studies

6. Questions?

Buildings consume 20% of the world’s available water, a resource that

becomes scarcer each year, according to the United Nations

Environmental Program.

EPA estimates that approximately 8% of all energy use in the USA

is directly related to pumping, treating, or heating water.

Power production is the largest consumer of fresh water daily

(~200 Bgals/day in 1995) more than irrigation, more than public

supply

Residential and commercial buildings use 12% of freshwater

consumed in the U.S.

Water Efficiency – Why?

• Water has been a secondary consideration during the development, design,

construction and operation of buildings. A stand-alone standard gives water

efficiency more weight.

• Standard 189.1, the International Green Construction Code (IGCC), and the

IAPMO Green Plumbing and Mechanical Code Supplement (GPMCS) have

been further developed, but these documents are more comprehensive and

are not solely focused on water efficiency.

• Many projects will not be required to meet 189.1 or the two green codes.

• Standard189.1 would reference the 191 baseline to ensure that both

documents provide a consistent message with regard to water efficiency

requirements.

Why ASHRAE SPC 191?

• There are no water efficiency ANSI standards completed or in development

that are focused only on water efficient building design considerations.

• The IGCC and the IAPMO documents are supplementary code documents

written in code language and are not ANSI standards. ASHRAE 191 is

targeted to be an ANSI standard written in mandatory language.

• A minimum standard for water efficiency, similar to 90.1 (Energy) and 62.1

(IAQ), would be of great value to the industry.

Why ASHRAE SPC 191?

Why ASHRAE SPC 191?

• Federal Mandates on Water Conservation

• E.O. 13423 mandates a reduction in water consumption intensity

(gallon/square foot) by 16% by the end of fiscal year 2015 from a 2007

baseline.

• E.O. 13514 expands these requirements, mandating Federal agencies to

improve water efficiency by:

• Reducing potable water consumption intensity 2% annually through

fiscal year 2020, or 26% by the end of fiscal year 2020, relative to a

fiscal year 2007 baseline.

In a typical office building, HVAC

systems account for approx. one third

of water consumption.

This increases for health-science

buildings and facilities where food is

prepared and served.

Therefore, minimizing the water

needed to operate HVAC systems

while not significantly increasing

energy usage should be a major

consideration in high performance

building design.

Water Efficiency- Opportunities

Energy production requires a reliable,

abundant, and predictable source of water,

a resource that is already in short supply

throughout much of the U.S. and the world.

The electricity industry is second only to

agriculture as the largest user of water in

the United States.

Electricity production from fossil fuels and

nuclear energy requires 190,000 million

gallons of water per day, accounting for

39% of all freshwater withdrawals in the

nation, with 71% of that going to fossil-fuel

electricity generation alone.

Water and Energy

According to the World Health

Organization, approximately 2.4

billion people live in highly

water-stressed areas. Two

primary solutions—shipping in

water over long distances or

cleaning nearby but dirty

supplies—both require large

amounts of energy. Therefore,

there is a significant amount of

embodied energy in the water

we use to drink, cook, flush

toilets and bathe.

Water Supply

Water Supply

Water Efficiency Opportunities:

US water consumption is

highest per capita.

The potential for replacing potable water with some form of

alternative water source is highly dependent upon a variety of

factors, including but not limited to:

Water Quality

Quantity

Demand

Human Health and Safety

Storage Requirements

Treatment

Codes, Laws & Ordinances

Codes

Maintenance and Service

Environmental Benefit

Water and Sewer Rates

Water Efficiency Considerations

Session Agenda: 1. Why develop an ASHRAE water standard?

2. Overview of Proposed ASHRAE Standard 191 on Water Efficiency

3. Comparison of Existing Water Standards and Codes

4. Design Considerations

5. Case Studies

6. Questions?

ASHRAE SPC 191

ASHRAE SPC 191- Purpose

The purpose of this standard is to provide baseline requirements for the

design of buildings, site, and mechanical systems that minimizes the

volume of water required to operate HVAC systems, plumbing systems,

and irrigation systems.

Balance environmental responsibility, resource efficiency, process

efficacy, and community sensitivity, and

Support the goal of the development that meets the needs of the present

without compromising the ability of future generations to meet their own

needs.

ASHRAE SPC 191- Partners

Intended to be an ASHRAE standard. Official partners are:

• AWWA

• USGBC

• ASPE

Also collaborating with many other organizations like the EPA, NREL, etc.

ASHRAE SPC 191-Scope

This standard provides baseline criteria that:

Applies to new buildings and renovation projects (new portions of

buildings and their systems) and the surrounding site: a building or

group of buildings, which utilize a single submittal for a construction

permit or which are within the boundary of a contiguous area under

single ownership.

Addresses water use efficiency through the concept of best practices

for water conservation measures implemented during design and

construction of residential, commercial, institutional and industrial

projects. .

ASHRAE SPC 191-Scope

The provisions of this standard do not apply to:

• Storm or building waste water management, except as a means of

reducing potable water use.

• Industrial process systems.

• This standard shall not be used to circumvent any safety, health or

environmental requirements.

ASHRAE SPC 191-Public Review Period

The public review period for BSR/ASHRAE/USGBC/ASPE/AWWA

Standard 191P began on October 26, 2012 and ran through December

10, 2012 (45-days). The draft is posted on the ASHRAE website at:

https://osr.ashrae.org/default.aspx

A final draft for public review is scheduled to be issued before the end

of this calendar year.

Instructions for submitting comments are available on the ASHRAE

website at: http://www.ashrae.org/standards-research--technology/public-review-drafts

Targeting summer of 2015 for publication

ASHRAE SPC 191-Sections

Section 4 – Building Sites • Standards and requirements for the installation of landscapes and

supplemental use of irrigation systems to irrigate those landscapes, if

required and used.

Section 5 – Alternate Sources and Treatment of Non-Potable Water • Standards and requirements for the use of alternate sources of water for

non-potable purposes.

Section 6 – Plumbing Systems • Standards and requirements for the installation of plumbing fixtures and

fittings, appliances, meters, graywater reuse systems, and water heating

and distribution systems.

ASHRAE SPC 191-Sections

Section 7 – HVAC Systems and Equipment • Water efficiency requirements for evaporative heat rejection equipment,

hydronic closed systems, ground source heat pump systems,

humidification systems, evaporative coolers, steam and hot water

systems, thermal storage systems, condensate drainage, and air

washers.

Section 8 – Appliances and Equipment • Water efficiency requirements for appliances and equipment for different

applications, including commercial food service operations, medical and

health care systems, laundering systems, laboratory facilities, and

residential appliances.

Other Key Goals of ASHRAE SPC 191

Intended to be a minimum, baseline standard

Intended to be similar in format and impact to ASHRAE Standards 90.1

and 62.1

Intended to be referenced by other green building codes and standards,

i.e. ASHRAE Standard189.1

Session Agenda: 1. Why develop an ASHRAE water standard?

2. Overview of Proposed ASHRAE Standard 191 on Water Efficiency

3. Comparison of Existing Water Standards and Codes

4. Design Considerations

5. Case Studies

6. Questions?

Comparison of Water Standards and Codes

Comparison of Water Standards and Codes

Comparison of Water Standards and Codes

Comparison of Water Standards and Codes

Comparison of Water Standards and Codes

Comparison of Water Standards and Codes

Comparison of Water Standards and Codes

Session Agenda: 1. Why develop an ASHRAE water standard?

2. Overview of Proposed ASHRAE Standard 191 on Water Efficiency

3. Comparison of Existing Water Standards and Codes

4. Design Considerations

5. Case Studies

6. Questions?

Design Considerations

How will a design engineer apply the water

efficiency standard requirements on projects?

Once-Through Cooling

Once-Through Cooling

Source: http://www1.eere.energy.gov/femp/program/waterefficiency_bmp9.html

Labs21 Best Practices

Flow Control:

….”Many pieces of lab equipment are “on”

continuously, even when the process runs only a few

hours per day or a few days per year. Often, the water

flow to some of this equipment is only a few gallons per

minute. However, a continuous 1.5-gpm trickle flow

through a small cooling unit adds up to 788,400

gallons per year. “…

The federal energy management program has identified

the elimination of single pass water cooling of

equipment as a “Best Management Practice”.

Once-Through Cooling

Once Through Cooling is Banned in Many Cities,

Including St. Louis

Metropolitan St. Louis Sewer District, Ordinance No.

12559, enacted August 14, 1991, Articles Four and

Five, Paragraph E.4:

“Prohibited discharge to Sanitary or Storm Sewers:

No person shall discharge or cause to be discharge into

any sanitary sewer any:…Cooling water which is

from a non-contact once through operation and

which is not treated prior to or during use”

“…Violation of this ordinance can result in a fine of

$1,000 and up to one year in jail…for each instance”

Once-Through Cooling

Single Pass Cooling Examples:

• Point-of-use chillers or other

refrigeration systems

• Laboratory Condensers

• Cryostats

• Air compressors

• Air conditioners

• Hydraulic equipment

• CAT scanners

• Degreasers

• Welding machines

• Vacuum pumps

• X-ray equipment

• Ice machines

• Wok stoves

• Condensate Coolers

Single

Pass

Cooling

Sustainability

A single fume hood device or

experiment using once through

water cooling can waste over

750,000 gallons of drinking water

per year.

Consider this potential scenario:

Cooling towers increase efficiency by 0.2 to 0.6 kWh/ton-hr = 1.4 to 4.2 cents/ton-hr.

The cost of water and water treatment is in the range of 2.0 to 3.0 cents per ton-hour and towers consume 0.02 – 0.05 kWh for pumps and fans

For cooling towers to be cost effective over air, energy efficiency must increase by at least 40%. That is approximately equal to an increase from 0.95 kWh/ton-hr to 0.55kWh/ton-hr.

Add costs for additional labor and concern for air pollution and possible legionella from drift.

Cooling Towers vs. Air Cooled Systems

Cooling towers serving water-cooled chillers are large consumers of

potable water in commercial and industrial buildings

Water saved at the power plant, even if gray water, frees up potable and

gray water elsewhere

Cooling Towers vs. Air Cooled Systems

Total water consumption is sum of the following:

• Power plant water usage

• Cooling plant water usage (if applicable)

• Direct and indirect evaporative cooling water usage (if applicable)

Cooling Towers vs. Air Cooled Systems

Potential Uses for HVAC Condensate

• Cooling Water

• Industrial Process Water

• Irrigation

• Potable Water

Condensate Collection Systems

Condensate Collection Systems

Potential Benefits for HVAC Condensate

• Reduced Potable Water Use

• Very low in Total Dissolved Solids

• High Quality Source of Water

• Fairly Constant and Reliable Source in Many Areas

• Lower Water & Sewer Bills

Condensate Collection Systems

Potential Risks for HVAC Condensate

• Lower pH – Can be Very Corrosive

• Can Carry Contaminants that Originate in the AC System or

Condensate Drain Pan. It is Highly Important to Keep the Entire

HVAC System Clean

• If Considering Potable Use, it is Very Important that All Surfaces

consist of Food Grade Materials

• Should be Treated if Stored or Aerosolized

Session Agenda: 1. Why develop an ASHRAE water standard?

2. Overview of Proposed ASHRAE Standard 191 on Water Efficiency

3. Comparison of Existing Water Standards and Codes

4. Design Considerations

5. Case Studies

6. Questions?

Case Study

King Faisal Specialist Hospital

Riyadh, Saudi Arabia

Case Study

Potable water service is

much more difficult to

supply at consistent,

cost effective levels.

Energy Use per 1000 gallons of water delivered

0

2

4

6

8

10

12

kWh

per

100

0 G

allo

ns Well Water

Surface Water

Brackish Water

Sea Water

Energy in Water

Case Study

Chilled Water Plant: Air-cooled Options

Option 1: 5,000 ton centrifugal chillers with dry coolers

Option 2: 2,000 ton centrifugal chillers with dry coolers

Option 3: Packaged Air Cooled Chillers (365 tons ea.)

Air Cooled 241,132,913 -

Water Cooled - Municipal 115,324,369 3,919,945

Water Cooled - Well 153,852,912 -

kWh/year

Municipal Water Use (M3)

Case Study

Case Study

HVAC Systems Life Cycle Cost Analysis

Summary of Options

$0.00

$2,000,000.00

$4,000,000.00

$6,000,000.00

$8,000,000.00

$10,000,000.00

$12,000,000.00

5000 Ton Chillers withDrycoolers

2000 Ton Chillers withDrycoolers

365 Ton Air Cooled Chillers

Annual Energy Cost (2) Annual Maintenance Cost

0

5

10

15

20

25

30

35

40

45

$0.00

$200,000,000.00

$400,000,000.00

$600,000,000.00

$800,000,000.00

$1,000,000,000.00

$1,200,000,000.00

5000 Ton Chillers withDrycoolers

2000 Ton Chillers withDrycoolers

365 Ton Air CooledChillers

System Installed Cost (1) 40 year Life Cycle Cost Chiller Life, Yrs

Interest Rate: 0.00

Inflation Rate: 3%

The University of Georgia

College of Veterinary Medicine

Athens, GA, USA

Case Study

Image Source: http://www.vet.uga.edu/giving/ugavii.php

Case Study

Condensate Collection System:

• Designed and installed in UGA’s

College of Veterinary Medicine

• Produces ~450,000 gallons of

condensate per year

• System cost was $3,200 installed

• Will save UGA $3,375/year

(assuming $0.0075/gallon)

• Simple payback is less than a

year Source: Prof. Tom Lawrence, The University of Georgia

Case Study

eVap™ Cooling System: Eliminates Once Through Water for Cooling

Case Study

eVap™ System Results in Significant Savings

Water Savings Example

Product Flow

Rate

(gpm)

Hours/Day

(Used)

Days/

Year

(Used)

Gallons/

Year

(Saved)

Cost/1000

Gallons

of Water*

Cost/1000

Gallons of

Sewer**

Annual

Water Cost

Savings

Annual

Sewer Cost

Savings

Total

Annual

Savings

eVap 1000 0.5 10 250 75,000 $3.19 $2.81 $239.25 $210.75 $450.00

eVap 1100 3 10 250 450,000 $3.19 $2.81 $1,435.50 $1,264.50 $2,700.00

eVap 1500 5 10 250 750,000 $3.19 $2.81 $2,392.50 $2,107.50 $4,500.00

eVap 1500 5 24 365 2,628,000 $3.19 $2.81 $8,383.32 $7,384.68 $15,768.00

*National Average Cost of water is $6.06 per 1,000 gallons. St. Louis region cost is $3.19/1,000 gallons.

**St. Louis region cost of sewer is $2.81 per 1,000 gallons.

Case Study

Post-Occupancy Research: Residence Hall Water Use

• Environmentally responsible decisions based on best practice design

and planning for projected outcomes.

• Analysis: Actual Water Use vs. Estimated Water Use (LEED Calculator)

• Development of water use benchmarks: gallons/occupant/day

3.25

1.86

2.25

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

Wate

r C

onsum

ption

[Mill

ions o

f G

allo

ns]

Baseline Annual CalculatedGallons (LEED)

Proposed Annual CalculatedGallons (LEED)

Actual Average AnnualGallons

Case Study

Residence Hall Water Use Research: Langdon Woods

Actual Water Use/Student/Day: 27 gal (‘09-10’), 22 gal (‘10-’11)

Actual 31% Better than Baseline

2.39

1.66

1.39

0.00

0.50

1.00

1.50

2.00

2.50

3.00

Wate

r C

onsum

ption

[Mill

ions o

f G

allo

ns]

Baseline Annual CalculatedGallons (LEED)

Proposed Annual CalculatedGallons (LEED)

Actual Average Annual Gallons

Case Study

Residence Hall Water Use Research: East Hall

Actual Water Use/Student/Day: 24 gal

Actual 42% Better than Baseline

Case Study

Post-Occupancy Research: Residence Hall Water Use

• Lessons Learned:

• Better water use prediction tools are needed

• LEED water-use reduction calculator does not cover items beyond

fixtures (i.e. laundry, mechanical systems, landscape, etc.)

• About 11-14% of water use is not considered in the LEED

calculator.

• Better water-use benchmarks are needed for modeling, testing and

comparison.

• More analysis of similar buildings are needed for a better data set.

Bill Hoffman- Austin, TX Water Conservation Program Presentation-

“Water & Energy Conservation: Relationships & Opportunities “

Michael Sherber- ASHRAE Presentation-

“WATER USAGE OF EVAPORATIVE COOLING AND VAPOR

COMPRESSION COOLING SYSTEMS”

Gary Klein- Green Plumbers Presentation-

“Water Efficient Technology Workshop”

Acknowledgements

Session Agenda: 1. Why develop an ASHRAE water standard?

2. Overview of Proposed ASHRAE Standard 191 on Water Efficiency

3. Comparison of Existing Water Standards and Codes

4. Design Considerations

5. Case Studies

6. Questions?

Questions?

John Swift, Jr., PE, LEED, CEM Principal – Cannon Design, Boston, MA

e: jswift@cannondesign.com

Smart Water Use:

Developing an ASHRAE Water Standard