RIGHT-SIZED:Equipment and Controls for Super Efficient Buildings|March 9, 2012|

PRESENTERS: Jim Keller, Jay Denny, Russ Landry,Julianne Laue

Funded By: ARRA Funds Energy Resource Manage office

Minnesota

Developed By: In partnership with:

Funded By: ARRA Funds Energy Resource Manage office

Minnesota

Developed By: In partnership with:

Special Thanks to:

Erik Kolderup, PE, LEED APKolderup Consulting

www.kolderupconsulting.com erik@kolderupconsulting.com

(415) 531-5198

3

Learning Objectives

• Right-sizing after applying passive energy conservation strategies

• Utilize controls to optimize the efficiency of equipment

• Energy efficient strategies to maintain occupant comfort

• Understanding energy flows in a building

4

Agenda

• Part 1 (12:30-2:00)– IAQ and Ventilation– Thermal Comfort– HVAC Loads– Energy Flows

• Break• Part 2 (2:10-3:00)

– HVAC System Alternatives– “Right-Sizing” HVAC Components– HVAC Controls– Selecting an HVAC System– The Architect’s Role

• Break• Exercise (3:10-3:40)• Right Sizing in Practice (3:40-4:00)• Case Studies (4:00-4:20)• Wrap Up (4:20-4:30)

5

EnergyFlows

6

Three Key Energy Flow IssuesHeat Flow from One “Thing”

to AnotherMoving Heat from One Place

to Another

Moving Heat “Uphill”

7

Getting Heat from One “Thing” to Another

• Heat Naturally Flows “Downhill” from Hot to Cold– The bigger the temperature difference, the faster the heat

flows– The bigger the area, the faster the heat flows

8

Carrying Heat from One Place to Another

• Heat Carried by Water or Air– Depends on temperature change (TD or T)– Depends on water or air flow rate

Temperature

Ener

gy P

er P

ound

=

9

Carrying Heat from One Place to Another

• Refrigerants--Evaporation(Boiling)/Condensing is “Freeze-Dried” Version– Can carry a lot of energy with

little fluid– Little temperature change needed– Used in Refrigeration systems

(evaporation = boiling)

Temperature

Ener

gy P

er P

ound

Boiling orCondensing

10

Carrying Heat from One Place to Another• Refrigerants—Controlling

Temperature of Heat– Change pressure to control

temperature of evaporation/condensing

– Pressurize to move heat uphill

Pressure

Boiling/Condensation Temperature

11

Carrying Heat from One Place to Another

Temperature

Ener

gy P

er P

ound

Evap

orati

on --

>Pressure

Boiling/Condensation Temperature

Condensation -->

Pressure

Pressure

• Refrigerants—Controlling Temperature of Heat– Change pressure to control

temperature of evaporation/condensing

– Pressurize to move heat uphill

12

Moving Heat “Uphill” (aka Refrigeration)

– Energy must be added to move heat uphill

– That extra energy ends up as more heat

– The farther “uphill” the heat is moved, the more energy it takes

Tem

pera

ture

13

Moving Heat “Uphill” (aka Refrigeration)

Tem

pera

ture

– Energy must be added to move heat uphill

– That extra energy ends up as more heat

– The farther “uphill” the heat is moved, the more energy it takes

14

Moving Heat “Uphill” (aka Refrigeration)

Tem

pera

ture

– Energy must be added to move heat uphill

– That extra energy ends up as more heat

– The farther “uphill” the heat is moved, the more energy it takes

Room Heat Gain & Loss Components

Lighting

Other?

Occupants

Conduction through opaque

envelope

Solar radiation through windows

Conduction through

windows Office equipment

Internal heat gains

External heat gains

Infiltration through cracks

16

Getting Heat Into a Space in a Building:“Typical” Central System

-20°F

0°F

20°F

40°F

60°F

80°F

100°F

120°F

140°F

160°F

180°F

Gas, Coal or Oil3,500 – 4,000F

Boiler Water 180FBoiler

Radi

ator

s

Air H

andl

er/V

AV

Space

Heated Air

Mixed or Cooled Air

Mi x

~350 to 400F

17

Getting The “Rated” Efficiency Out of Condensing Boilers (>90% Efficiency)

Heated Air

75%

80%

85%

90%

95%

100%

80°F 100°F 120°F 140°F 160°F 180°F

Entering Water Temperature

Bo

iler

Eff

icie

ncy

Natural Draft

EnergyStar Min

Condensing Boiler

18

_______ Chart for Showing Moisture in Air Issues

• Curve at Top Shows When Air Can’t Hold Any More Moisture (aka saturated)

• Once At the Top, Cooling More Condenses Moisture Out of Air

Air Temperature

Amou

nt o

f Moi

stur

e (a

ka S

team

) in

Air

140F100F60F

19

Getting The “Rated” Efficiency Out of Condensing Boilers (>90% Efficiency)

Heated Air

75%

80%

85%

90%

95%

100%

80°F 100°F 120°F 140°F 160°F 180°F

Entering Water Temperature

Bo

iler

Eff

icie

ncy

Natural Draft

EnergyStar Min

Condensing Boiler

Direct-Fired Heater

20

_______ Chart for Showing Moisture in Air Issues

• Moisture is Much More Diluted in Direct-Fired Heater

• It Reaches a Lower Temperature, but Never Condenses(THANK GOODNESS!)

Air Temperature

Amou

nt o

f Moi

stur

e (a

ka S

team

) in

Air

140F100F60F

Direct Fired Heater

21

Getting Heat Into a Space in a Building:“Typical” Central System

-20°F

0°F

20°F

40°F

60°F

80°F

100°F

120°F

140°F

160°F

180°F

Gas, Coal or Oil3,500 – 4,000F

Boiler Water 180FBoiler

Radi

ator

s

Air H

andl

er/V

AV

Space

Heated Air

Mixed or Cooled Air

Mi x

~350 to 400F

22

Getting Heat from One “Thing” to Another

• Heat Naturally Flows “Downhill” from Hot to Cold– Via conduction (key in solids), convection (moving gas or liquid),

and/or radiation

– The bigger the temperature difference, the faster the heat flows

– The bigger the area, the faster the heat flows• Moving Heat “Uphill” Takes Energy

– There’s a minimum possible energy required for a given rise in temperature

– The farther “uphill” the heat is moved, the more energy it takes– All Forms of Energy Put into Something Eventually End up as

Heat

23

Central System Designed for Condensing Boilers

-20°F

0°F

20°F

40°F

60°F

80°F

100°F

120°F

140°F

160°F

180°F

Gas at 3,500F

Boiler Water 160F Average

BoilerRa

diat

ors

Space 75F

Heated Air

Mixed or Cooled Air

M ix

Radi

ant

Fl

oor

+

Air

Han

dler

/VAV

24

Central System Designed for Condensing Boilers

-20°F

0°F

20°F

40°F

60°F

80°F

100°F

120°F

140°F

160°F

180°F

Boiler Water 150F Average

Space 75F

60F DropTraditional 20F Drop

25

Getting The “Rated” Efficiency Out of Condensing Boilers (>90% Efficiency)

Heated Air

75%

80%

85%

90%

95%

100%

80°F 100°F 120°F 140°F 160°F 180°F

Entering Water Temperature

Bo

iler

Eff

icie

ncy

Natural Draft

EnergyStar Min

Traditional 20F Drop

60F Drop

26

-20°F

0°F

20°F

40°F

60°F

80°F

100°F

120°F

Getting Heat Into a Space in a Building:Heat Pumps—Air Source & Ground Source

Air Source HP

Space

Heated Air

MixAir Source H

P

Mix

Air Source

27

-20°F

0°F

20°F

40°F

60°F

80°F

100°F

120°F

Getting Heat Into a Space in a Building:Heat Pumps—Air Source & Ground Source

Air Source HP

Space

Heated Air

MixAir Source H

P

Mix

Ground

Air Source Ground Source

Ground Source H

P

Water/Glycol

28

-20°F

0°F

20°F

40°F

60°F

80°F

100°F

120°F

Getting Heat Out of a Space in a Building:Typical Systems

Space

ChillerM ix

Chilled Water

Chiller

Cooled Air

Refrigerant in Chiller

Refrigerant in Chiller

Air CooledHigher Peak Lift

Water CooledLower Peak Lift

Cooling Tower Water

M ix

DX

29

_______ Chart for Showing Moisture in Air Issues

• Air Cooled Refrigerant Loses Heat to Air Temperature

• Evaporation Loses Heat to a Lower Temperature (Wet Bulb)

Air Temperature

Amou

nt o

f Moi

stur

e (a

ka S

team

) in

Air

95F75F55F

30

-20°F

0°F

20°F

40°F

60°F

80°F

100°F

120°F

Getting Heat Out of a Space in a Building:Economizer

Space

M ix

Chilled Water Cooled Air

Refrigerant in Chiller

Recirculated & Cooled Air

Economizer(Outdoor Air)

At Low Temperatures Mixing Outdoor and Room Air Does All Cooling

At Mild Temperatures All Outdoor Air Does Part of Cooling

31

Moving Heat from One Place to Another

Air Water RefrigerantTemperature Drop 20 10 -

Heat Carrying Capacity: BTU per Pound 5 10 50

Fluid Transport Energy Factor: Watts per lb/hr 0.17 0.04 0.27

Heat Transport Enegy Factor: Watts per BTU/hr 35 4 5

32

Water vs. Air

• Water good…– Moving heat via water typically requires less energy– Pipe much smaller than equivalent duct

• But…– Still need ventilation in many cases

• May need a fan and duct anyway

– Air distribution system typically less expensive– Air system can provide “free” cooling with outdoor air