Mechanical Disciplinary Research

Marissa Caldwell, Anya Godigamuwe, Valerie Miller,Yuka Narisako, Jimmy Weaver

Variable Refrigerant Flow Systems (VRF)

[James Weaver]

The Vapor Compression Cycle

Expansion Valve

Compressor

Evaporator Coil

Condenser Coil

Variable Refrigerant Flow/Volume Systems

Figure 2: VRV System in a tall building. Provided by Daikin Industries, Ltd.

A VRF System operates by sending refrigerant between an outdoor and indoor unit.

The outdoor unit houses the condenser and compressor.

The indoor unit houses the evaporator. Refrigerant is varied to each indoor unit

based on the desired load using electronic expansion valves or pulse modulating valves.

Heat Recovery is available through the reuse of energy from superheated refrigerant.

Goetzler, William. Variable Refrigerant Flow Systems. ASHRAE Journal. April 2007.

Advantages Vs. Disadvantages Advantages: Lightweight and modular Flexible Design Minimal Ductwork Individual Comfort Control Energy Efficient – High Part Load

Efficiency

Disadvantages: Initial Costs Refrigerant Piping Concerns Cold Climate Issues Market Acceptance Many Require a Dedicated Outdoor Air

System

Figure 3: Heat Recovery VRF System. Provided by ASHRAE Journal, April 2007.

Goetzler, William. Variable Refrigerant Flow Systems. ASHRAE Journal. April 2007.

Potential Project Benefits

Figure 4: Temperature distribution in a building. Provided by Daikin Industries, Ltd.

Figure 5: VRV system with 100% Outside Air Unit. Provided by Daikin Industries, Ltd.

A multi-purpose building can benefit from space by space comfort control.

Minimal Ductwork can provide solutions to challenging space and coordination issues.

Energy performance from a VRF system can improve a building operational costs.

Goetzler, William. Variable Refrigerant Flow Systems. ASHRAE Journal. April 2007.

Thermal Energy Storage

[Yuka Narisako]

Thermal Energy Storage – Definition Store unused energy when it is undesired and

release it when it is necessary to reduce energy waste.

http://www.calmac.com/products/icebank.asp

Thermal Energy Storage – Types of Systems Time/Consumption

based Peak shaving

Heating Hot water tanks in homes Thermal mass

Cooling Water pumped from dams Water storage units Ice storage units

http://www.calmac.com/products/icebank.asp

Thermal Energy Storage – Real World Example Nissan Technical Center

North America Inc. Farmington Hills, MI

Duquesne University Pittsburgh, PA Add ice making chiller and

ice storage unit

http://www.energystorageexchange.org/

Thermal Energy Storage – Possible Use for Project Reduce cooling load by installing small chiller

and ice storage unit Lower cost Reduce size of mechanical room Possibly provide cooling for future

Energy Recovery Ventilator (ERV)

[Valerie Miller]

[Energy Recovery Ventilator] – Definition Energy Recovery Ventilators (ERV’s) utilize

conditioned waste air energy to precondition outdoor air, by the use of a heat exchanger.

Heating and cooling All ERV’s transfer sensible heat (temperature);

some types transfer latent heat (humidity)

Space Airconditioning PLCSustainable Sources

[Energy Recovery Ventilator] – Types of Systems Thermal Wheel Plate to Plate Runaround Coil

Fastlane: Ventilation Equipment LimitedLive Building: Integrated Learning Centre

[Energy Recovery Ventilator] – Types of Systems Thermal Wheel

Enthalpy Wheel Wheel spins between exhaust

and outdoor air duct, transferring the heat from the hotter air to the cooler air

Sensible and Latent heat; transfers heat and moisture

Small cross-contamination Ducts must be close

Plate to Plate Runaround Coil

Fastlane: Ventilation Equipment LimitedLive Building: Integrated Learning Centre

Sacramental Municipal Utility District Energy Info. Library

Fastlane: Ventilation Equipment Limited

[Energy Recovery Ventilator] – Types of Systems Thermal Wheel Plate to Plate

Air streams pass through alternating plates

Air streams never come in contact; no cross-contamination

Ducts must be close Runaround Coil

Fastlane: Ventilation Equipment LimitedLive Building: Integrated Learning Centre

Fantronix Online Ventilation Solutions

Fastlane: Ventilation Equipment Limited

[Energy Recovery Ventilator] – Types of Systems Thermal Wheel Plate to Plate Runaround Coil

Coil’s containing a medium run through the exhaust system

No cross-contamination Ducts can be any

distance

Fastlane: Ventilation Equipment LimitedLive Building: Integrated Learning Centre

Fastlane: Ventilation Equipment Limited

[Energy Recovery Ventilator] – Types of Systems

Fastlane: Ventilation Equipment LimitedLive Building: Integrated Learning CentreTrane

Thermal Wheel

Plate to Plate Runaround Coil

0102030405060708090

100Heat Exchanger Efficiency

HeatingCooling

Effici

ency

(%)

[Energy Recovery Ventilator] – Example McAllister Building

(2) enthalpy wheel ERV’s 73.7% and 71.4% effective <0.04% cross-contamination

OPP Commissioning Wikispaces

[Energy Recovery Ventilator] – Example Carnegie Mellon University's

Intelligent Workplace Enthalpy wheel Reduced heating load by 77%

James W. Meacham’s Spring 2003 Senior Thesis Grade School, Philadelphia, PA Enthalpy Wheel cost summary

showed a cost savings of ~$25,000 in the first year, a 4 day payback period

Installing an Enthalpy Wheel in new construction allows you to downsize equipment and save money up-front Florida school saved $25,000 up-

front by equipment downsizingProceedings of IMEC2006: 2006 ASME International Mechanical Engineering Congress and ExpositionAn FPL Technical Primer: Energy Recovery VentilationGreenheck: Energy Recovery Application Manual:

http://www.flickr.com/photos/32215181@N08/5521845253/in/photostream/

Greenheck: Energy Recovery Application Manual:

Earth-Coupled Systems

[Anya Godigamuwe]

Earth-Coupled Systems– Definition Using the near

constant temperature of the Earth to heat spaces in winter and to cool spaces in summer

Introduction to Geothermal Technologies / Egg & Howard

Earth-Coupled Systems– Types of Systems

Closed Loop

Introduction to Geothermal Technologies / Egg & Howard

Earth-Coupled Systems– Types of Systems

Open toReinjection

Introduction to Geothermal Technologies / Egg & Howard

Earth-Coupled Systems– Types of Systems

StandingColumn

Introduction to Geothermal Technologies / Egg & Howard

Earth-Coupled Systems– Real World Example 7R Building at EEB Hub, Navy Yard,

Philadelphia

Source: KieranTimberlake

Earth-Coupled Systems– Real World Example 7R Building at EEB Hub, Navy Yard,

Philadelphia

Source: KieranTimberlake

Earth-Coupled Systems– Possible Use for Project

Pros Cons Could provide 80%

heating/cooling needs

Short payoff period

Not suited for 24/7 cooling

Requires a large area of land

Introduction to Geothermal Technologies / Egg & Howard

Radiant Floor Heating

Marissa Caldwell

Radiant Floor Heating – Definition Supplies heat to the floor

from tubing or cables under the floor

Radiant Heat Transfer Heats from floor up Natural circulation

through convection

http://energy.gov/energysaver/articles/radiant-heating

Hydronic vs. Electric Hydronic

Uses pumps and valves to regulate flow based on design temps

Longer to heat up floor Requires a boiler

Electric Uses conduit to pass

electricity at night to heat the thermal mass, and radiate heat during the day

Radiant Floor Heating– Types of Systems Wet Installation

Tubing is placed within the concrete slab

Allows for the use of energy storage in the thermal mass

Dry Installation Plywood is placed on top of the

tubing It can be either sandwiched in or

the tubing is stapled to the underside of the flooring

http://energy.gov/energysaver/articles/radiant-heating

Radiant Floor Heating – Real World Example Herbert Jacobs House – Wisconsin

Wright 1st to use radiant floor heating in a US home

Hearst Tower – New York Radiant floor heating was added in their three-

story atrium to avoid heating unoccupied space California Academy of Sciences – California

35-foot-high museum space, reduced energy through heating by 10%

http://www.calacademy.org/academy/building/sustainable_design/

Radiant Floor Heating – Possible Use for Project This system is ideal for large spaces with high

ceilings Improved indoor air quality Inexpensive if the building already has a boiler Allows for open layouts

Thermal Dynamics of Radiant Floor Heating – Darren Cent