NET ENERGY WATER LOOPS - MN ASHRAEmnashrae.org/downloads/Refrigeration_Seminar_2017/... · mass heat Net Energy Water Loops . ... refrigeration cases, snow melt, ice rinks, process

Presents

NET ENERGY WATER LOOPS A clear path to net zero energy buildings

Alan Niles WaterFurnace International

Net Zero Energy Building Design:

• Analyze the unique energy profile of the building

• Increase the efficiency of each system as they function as part of a

whole within the building

• Share energy across all of the systems within the building to minimize

waste energy

Net Energy Water Loops

Net Zero Energy Building Design:

• Analyze the unique energy profile of the building

• Increase the efficiency of each system as they function as part of a

whole within the building

• Share energy across all of the systems within the building to minimize

waste energy

The Goal:

• Reduce the energy foot print without sacrificing comfort or functionality

• Increase the impact of onsite renewable energy


HVAC Systems for a Net Zero Energy Building Design

must meet specific characteristics:

1. Capture and effectively transport energy from HVAC and non-HVAC sources

throughout the structure

2. Be scalable for any size building with minimal effects to overall efficiency

3. Provide maximum efficiency and maximum comfort with controllable

performance for each zone

4. Easily connect to onsite renewable energy opportunities


Requirements for a Net Energy Loop:

Low cost transportation of energy throughout the building

AIR

1. Requires a large amount of conditioned space to run ductwork

2. Fan Power excessive as net energy air loop increases




REFRIGERANT

1. Can only share energy within a single circuit

2. Compressor losses limits scalability (440 equivalent feet of line sets

causes 20% reduction in compressor efficiency)




WATER

1. Moves energy 10 times more efficient than air

2. Small diameter piping moves large amount of energy

3. Scalable and easy to shut off flow to zones that are satisfied for

minimizing operating costs of the transportation system

4. Easy to connect to onsite renewables like solar, ground loop, and bio-

mass heat



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Start with a Water Loop Heat Pump (WLHP) System

LOW INSTALLED COST


Air Cooled VRF 33% 31% 30% no data

From Reps and Installing Contractors

LOW INSTALLED COST


GLHP System Dramatically reduces Peak Load

ASHRAE Headquarters in Atlanta Live Data Available online http://images.ashrae.biz/renovation/

January 1, 2012 to May 9, 2012 Energy Use


http://images.ashrae.biz/renovation/

ASHRAE Headquarters in Atlanta

2010 HVAC Energy

GLHP = 25.26 kWh / sq. ft. / year

VRF = 39.66 kWh / sq. ft. / year



2010 HVAC Energy

GSHP = 25.26 kWh / sq. ft. / year

VRF = 39.66 kWh / sq. ft. / year



2010 to 2012 HVAC Energy






Hides above the ceiling increasing leasable space


Horizontal Cabinets Mirror Image Air Flow Patterns

Discharge Air Flow Pattern is Field Convertible




Vertical Cabinets Mirror Image Air Flow Patterns



Maximum Comfort at the Lowest Operating Cost for your budget

THE WLHP SYSTEM BECOMES THE BACKBONE OF

A BUILDING-WIDE NET ENERGY WATER LOOP


Integrate as much system efficiency as your budget

allows

• Upgrade to High Efficiency WSHP’s

• Add Heat Recovery for DHW

• Add Heat Recovery to Exhaust Air/Makeup Air

• Add Renewable Energy Hybrid Ground Loop

• Add other Renewable Energy (solar, wind, biomass)

• Integrate chilled beam, radiant floor, six pipe simultaneous chiller/boiler technology

• Integrate non-HVAC equipment:

- ice making machines, freezer cases, refrigeration cases, snow melt, ice rinks, process water, black water waste, grey water, sprinkler water



allows

Upgrade to High Efficiency WSHP’s

• Standard efficiency 12 EER means for every 1 watt of electricity consumed,

3.52 watts of energy is removed from the conditioned space (1 ton of cooling)

resulting in 4.52 watts of waste heat delivered to the net energy water loop

• High efficiency 21.6 EER reduces the electricity consumed from 1 watt to only

0.56 watts to remove the same amount of energy from the zone and reduces

the waste heat delivered to the net energy water loop from 4.52 watts to 4.08

watts


Impact of system efficiency and waste heat to a ground loop

Basis of Design:

60 bore holes x 305 ft per hole x $10/ft

Total: $ 183,000.00

75.5 Connected Tons of GLHP’s

Cost of Heat Pumps with Accessories

$ 60,000.00

Basis of Design 20.0 EER

Alternate # 1 18.5 EER





Basis of Design:


Total: $ 183,000.00

Add for Alt #1:

60 bore holes X 5 ft per hole = 300 bore ft

Plus 8 holes X 310 ft = 2,480 bore ft

Total: 2,780 bore ft X $10/ft = $ 27,800.00 15% add



$ 60,000.00







Basis of Design:


Total: $ 183,000.00

Add for Alt #1:




Add for Alt # 2:

16 holes X 305 ft = 4,880 bore ft

Total: 4,880 bore ft X $10/ft = $ 48,800.00 27% add 75.5 Connected Tons of GLHP’s


$ 60,000.00







Basis of Design:


Total: $ 183,000.00

Add for Alt #1:




Add for Alt # 2:

16 holes X 305 ft = 4,880 bore ft


Add for Alt # 3:

60 holes X 10 ft per hole = 600 bore ft





$ 60,000.00







allows

• Add Heat Recovery to DHW

• Add Heat Recovery from Exhaust Air/Makeup Air



ASHRAE 90.1-2010

Section 6.5.6.2.1 and 6.5.6.2.2

The required heat recovery system shall have the capacity to

provide (as a minimum) the smaller of:

a. 60% of the peak heat rejection load at design conditions, or

b. preheat of the peak service hot water draw to 85°F.

How much heat can be recovered

from the HVAC system?


Heat Recovery Calculation

Given: 100 ton Building

Zone Distribution: 60% core (60 tons), 40% perimeter (40 tons)

Snap Shot Winter Occupied Mode: 65% of core in cooling mode, 85% of perimeter in heating mode

Core (cooling mode)

60 tons x 0.65 (percent running) x 3 GPM/ton x 10 F (rise) x 500 = 585,000 BTUH heat rejected

Perimeter (heating mode)

40 tons x 0.85 (percent running) x 3 GPM/ton x 6 F (drop) x 500 = 306,000 BTUH heat absorbed

Net Heat Gain to the Net Energy Water Loop = 279,000 BTUH


Heat Recovery Calculation

Net Heat Gain to the Net Energy Water Loop = 279,000 BTUH

OA Pre-Heat Analysis

100 ton x 400 CFM/ton x 25% OA = 10,000 CFM of OA

Available Dry Bulb Rise of OA

279,000 BTUH / (10,000 CFM x 1.085) = 25 F Rise

100% recovered waste heat for preheating OA from 30F to 55F

Or DHW Pre-Heat Analysis

279,000 BTUH/(500 x (110 F LWT – 70 F EWT) = 14 gallon per minute

100% recovered waste heat for preheating 14 GPM of hot water or

840 gallons per hour




allows

• Add Renewable Energy Hybrid Ground Loop


85 F Supply Water

95 F Return Water

10F Across the Cooling Tower


95 F

90 F Return Water

79 F

85 F Supply Water

95 F 87 F

Only 5F Across the Cooling Tower

One unit in each zone with individual local temperature control


95 F

86.8 F Return Water

79 F

85 F Supply Water

95 F

84 F

Only 1.8F Across the Cooling Tower

Heat Recovery To OA AHU Snow Melt Domestic Hot Water Pre-Heat 130 F or 160 F Hot Water

Water-to-Water Unit


95 F

86.8 F Return Water

79 F

85 F Supply Water

95 F

84 F

Water-to-Water Unit

Only 1.8F to the Ground Loop

Heat Recovery To OA AHU Snow Melt Domestic Hot Water Pre-Heat 130 F or 160 F Hot Water


Supply Water approaches Ground Temperature

Typical Water Source Heat Pump Cooling Performance


33% Increase



33% Increase


Published EER is actual operating efficiency based on

specific operating conditions and the actual

Net cooling capacity of the WSHP

These are not seasonally adjusted IEER's or SEER's


Hybrid GLHP Systems

Take Advantage of Part Load Operation

Commercial Building Loads are only 50% or less of the Peak Load for

80% - 90% of the Year

Renewable Energy Hybrid GLHP Systems should be sold just like

Solar PV Panels

Only install the amount that is most economical


Take Advantage of Part Load Operation

50% of the hours In the year

27% Flow

80% of the hours In the year

54% Flow


552 GPM System (2.8 GPM/ton) with VFD Pumping

Maximize Property Area



Great River Medical Center – Burlington, Iowa 1500 Ton, 2002 ASHRAE Technology Award


allows

Using 6 Pipe chiller/boiler technology, integrate more hydronic

technologies in zones of the building where the application

makes sense:

• Chilled beam

• Underfloor Displacement Ventilation

• Radiant floor

• Ice Storage

• Integral Waterside Economizer


Six Pipe Simultaneous Chiller/Boiler

How It Works


Condenser Evaporator

Single Screw Compressor or Dual Scroll Compressors



Chilled Water Supply & Return

Hot Water Supply & Return

Net Energy Water Loop Supply & Return







Two Way Water Valves And Three Way Valves


Two Way Water Valves And Three Way Valves






Chilled Water Mode


Hot Water Mode







Simultaneous Chilled Water & Hot Water Mode







Simultaneous Chilled Water & Hot Water Mode







Partial Simultaneous

Mode







Allows for simultaneous control of both the Chilled Water and the Hot Water Set Point

Waterside Economizer

Mode















Primary Variable Speed Pumping

Hot Water Supply

Chilled Water Supply

Net Energy Loop



allows

Integrate non-HVAC systems and equipment:

ice making machines, freezer cases, refrigeration cases, snow melt, ice

rinks, process water, black water waste, grey water, sprinkler water



Black Water/Grey Water Heat Exchanger





Ice Making Machines, Freezer Cases, Refrigeration Cases,

Walk-in Freezers

AHRI Certified EER improves 20% using water cooled Ice

Making Machines as compared to air cooled machines. • Units are quieter

• Units do not add a heat load to the zone

• Units require less maintenance

Freezer and Refrigeration Cases are free sources of energy for

the Net Energy Water Loop and selecting "water cooled"

improves efficiency, reduces refrigerant charge, and improves

comfort by reducing sound levels


The GLHP system in this Minnesota gas

station heats and cools the building:

provides hot water, food refrigeration, and

ice making; and melts snow to and from the

carwash.

5 HP Cooler Case downsized to 3 HP

3 HP Freezer Case downsized to 1 HP

Integrating Hybrid Ground Loop, Snow Melt, DHW, Freezer Cases,

and Refrigeration Cases




allows

Add Renewable Energy

Solar PV Panels

Wind Power Generators

Solar Hot Water Panels

Co-Generation Bio-Mass

Questions ?

Alan Niles

Documents

NET ENERGY WATER LOOPS - MN ASHRAEmnashrae.org/downloads/Refrigeration_Seminar_2017/... · mass heat Net Energy Water Loops . ... refrigeration cases, snow melt, ice rinks, process