WHR & HVAC

1. Waste heat
recovery and HVAC
industry analysis





S u b m i t t e d t o C I I E , I I M A
B y : M a n v i n d r a Si n g h
3 r d y e a r u n d e r g r a d u a t e
M S E, I I T K a n p u r

9 5 5 9 7 5 3 6 5 8, 9 7 2 3 3 3 6 3 0 6

7 / 2 7 / 2 0 1 2
Manvindra Singh
This report cover opportunities and value proposition of
promising firms involved in waste heat recovery and
HVAC system.

2. Table of Contents
Contents
Technologies in Waste heat to energy and recovery .......................................................................... 3
Heat Exchangers ............................................................................................................................... 3
Low Temperature Energy Recovery Options and Technologies ........................................................... 4
Power Generation ................................................................................................................................ 4
Waste Heat Opportunity ...................................................................................................................... 5
Opportunity and Challenges ............................................................................................................ 5
Barriers:............................................................................................................................................ 6
Value proposition of Firms ................................................................................................................... 7
Ener-G-Rotors: ................................................................................................................................. 7
Enermotion: [] .................................................................................................................................. 7
Oregon State University ................................................................................................................... 7
BMW ................................................................................................................................................ 8
Eureka: ............................................................................................................................................. 8
Airec AB ............................................................................................................................................ 8
Entrans: ............................................................................................................................................ 9
Echogen Power Systems: ................................................................................................................. 9
HVAC systems .................................................................................................................................... 10
Trends in HVAC .............................................................................................................................. 10
Technologies involved: .................................................................................................................. 11
Value proposition ............................................................................................................................... 12
7AC Technologies: .......................................................................................................................... 12
Chromasun: .................................................................................................................................... 12
Save Energy Systems: USA based (commercial) ............................................................................ 13
Regenergy365: ............................................................................................................................... 13
Energy Recovery Technologies, LLC ............................................................................................... 13
EcoFactor: ...................................................................................................................................... 13
Optimum Energy: ........................................................................................................................... 14
Clean urban energy: ....................................................................................................................... 14
Appendix 1: ........................................................................................................................................ 15
Appendix 2 ......................................................................................................................................... 16

3. Appendix 3 ..................................................................................................................................... 17

4. Technologies in Waste heat to energy and recovery [1]
Sources of waste heat include hot combustion gases discharged to the atmosphere, heated
products exiting industrial processes, and heat transfer from hot equipment surfaces

Various studies have estimated that as much as 20 to 50% of industrial energy
consumption is ultimately discharged as waste heat

Waste heat recovery entails capturing and reusing the waste heat in industrial processes for
heating or for generating mechanical or electrical work.

Example uses for waste heat include generating electricity, preheating combustion air,
preheating furnace loads, absorption cooling, and space heating.

Evaluating the feasibility of waste heat recovery requires characterizing the waste heat source
and the stream to which the heat will be transferred

Important parameter
• heat quantity,
• heat temperature/quality,
• composition,
• Minimum allowed temperature, and operating schedules, availability, and other logistics.


Waste heat recovery option and Technologies

Methods for waste heat recovery include transferring heat between gases and/or liquids,
transferring heat to the load entering furnaces, generating mechanical and/or electrical power,
or using waste heat with a heat pump for heating or cooling facilities.

Temperature Range for waste heat classification

-High 1200ºF [650°C] and higher
-Medium 450ºF [230°C] to 1,200ºF [650°C]
-Low 450ºF [230°C] and lower

Temperature classification and work potential of
various industry are given in APPENDIX 2

Heat Exchangers


Heat exchangers are most commonly used to
transfer heat from combustion exhaust gases to
combustion air entering the furnace. Typical
technologies used for air preheating include
recuperators, furnace regenerators, burner
regenerators, rotary regenerators, and passive air

1
US-DOE ITP - Waste Heat Recovery; Technology and Opportunities in U.S. Industry
High temperature(>650 °C)
•Combustion preheat, Steam generation,
Furnace load preheating
•Transfer to low-mid Temperature
Medium Temperature(230 to 650°C)
•Combustion air Preheat, ORC power, Feed
water preheating, Furnace load preheating.
•District cooling, heating.
Low temperature( <230°C)
•Space heating, domestic water heating. ORC
power
•Adsorption chiller AC
•Thermoelectric

5. preheaters
Temperature classification, comparison of heat exchanger with other are given in appendix 1,3.

Low Temperature Energy Recovery Options and Technologies
While economics often limit the feasibility of low temperature waste heat recovery, there are
various applications were low grade waste heat has been cost effectively recovered for use in
industrial facilities. Much industrial waste heat is in the low temperature range.

In the case of combustion exhaust gases, substantial heat can be recovered if water vapor
contained in the gases is cooled to lower temperatures. Cooling the flue gas further could
significantly increase heat recovery by allowing the latent heat of vaporization to be recovered.
Power Generation
Generating power from waste heat typically involves using the waste heat from boilers to
create mechanical energy that then drives an electric generator. New Technologies includes
thermoelectric and piezoelectric generation. Important factor is the thermodynamic
limitations on power generation at different temperatures.



Source: 2008, US-DOE ITP - Waste Heat Recovery; Technology and Opportunities in U.S

6. Waste Heat Opportunity

60% of waste heat is at low temperature range






Opportunity and Challenges


1. Low temperature waste heat sources: About 60% of waste heat losses are at
temperatures below 450°F [230°C]. A major challenge for low temperature heat recovery
from exhaust gases is the condensation and corrosion caused by cooling exhaust gases
below their dew point temperature. Alternate technologies, such as transport membrane
condensers are being developed and may have lower costs.
Large heat transfer area required. Efforts can be made in further demonstrating
emerging power cycles, improving these power cycles, and developing alternative
generation systems.

2. Systems already including waste heat recovery that can be further optimized to
reduce heat losses
3. High temperature systems where heat recovery is less common : There are market
segments where waste heat recovery is less common; this is due to barriers such as
chemical constituents in exhaust gases that interfere with heat exchange, as well as
limitations on economies of scale for smaller waste heat streams.
4. Alternate waste heat sources typically not considered for waste heat recovery: This

7. focused on combustion and process exhaust gases. Alternates include heat radiated,
convected, and conducted from heated products (e.g., cast steel, hot cokes), as well as
heat lost in aluminum
cell sidewalls and after pyro-processes where slag or after materials are solidified to
protect the
vessel walls.
5. Easier maintenance: Develop economic recovery systems that can be easily
cleaned after exposure to gases with high chemical activity
6. Gas cleaning : Develop lowcost methods for cleaning exhaust gases.
7. New recovery technologies: Develop new heat recovery technologies such as
solid state generation

Barriers:
1. Cost: Long payback periods, Material constraints and costs
2. Economies-of-Scale: Equipment costs favor large scale heat recovery systems and create
challenges for small scale operations. Corrosion, scaling and fouling of heat exchange
materials lead to higher maintenance costs and lost productivity.
3. Temperature Restrictions: Materials that retain mechanical and chemical properties at
high temperatures are costly. Liquid and solid components can condense as hot streams
cool in recovery equipment, leading to corrosive and fouling conditions. The additional
cost of materials that can withstand corrosive environments often prevents low
temperature recovery. The heat flow in some industrial processes can vary dramatically
and create mechanical and chemical stress in equipment.
4. Chemical Composition: Waste heat stream chemical compatibility with recovery
equipment materials will be limited both at high and low temperatures. Deposition of
substances on the recovery equipment surface will reduce heat transfer rates and
efficiency. Streams with high chemical activity require more advanced recovery equipment
materials to withstand corrosive environments
5. Application Specific Constraints:
i) Process specific constraints – Equipment designs are process specific and must
be adapted to the needs of a given process. For example, feed preheat systems
vary significantly between glass furnaces, blast furnaces, and cement kilns.
ii) Product/ Process control – Heat recovery can complicate and compromise
process/quality control systems
iii) Inaccessibility/Transportability:
i. Limited space – Many facilities have limited physical space in which to
access waste heat streams (i.e., limited floor or overhead space)
ii. Transportability – Many waste heat gaseous streams are discharged near
atmospheric pressure (limiting the ability to transport them to and through
equipment without additional energy input).
iii. Inaccessibility – It is difficult to access and recover heat from
unconventional sources such as hot solid product streams (e.g., ingots) and
hot equipment surfaces (e.g., sidewalls of primary aluminum cells). Safety

8. and operational demands that require access around/above most melting
furnaces, boilers, heaters, and other high temperature equipment.
Value proposition of Firms

Ener-G-Rotors:
 Ener-G-Rotors is commercializing devices based on a near frictionless expander that turns
low- temperature heat into electricity based on organic rankine cycle.
 Their product(GEN4) could be used for industrial processes, commercial buildings, solar
thermal collectors, geothermal sources, biomass boilers and combustion engines.
 The equipment sells for $90,000 and pays for itself in as little as two years by generating
electricity. Its fourth-generation product can generate 40 to 60 kilowatts. It creates no
waste and uses heat waste from 65 to 176 C.[
2
]
 The innovation is how they hold the inner and outer rotor each on two sets of pre-loaded
roller element bearings, controlling the radial and axial tolerances of the inner and outer
rotors.
 Website: http://www.ener-g-rotors.com/
Enermotion: [
3]
 It develops fully functioning auxiliary power unit (APU) powered solely by waste heat
recovery which is capable of providing heating, cooling and load power for up to 10 hours
without any fuel consumption.
 It's estimated that as much as 30% of the energy produced by a diesel engine is lost
through the tailpipe in the form of heat. They utilizes the high-grade heat in big diesel
motors, anywhere from 300-800 degrees C. Their system ties into the stock exhaust.
 Based on metrics collected by EnerMotion , the company is expecting to reduce fuel
consumption by 9% with its system, providing a payback in less than a year - as long as it
works.
 It weighs about the same as a diesel-powered APU and contains no moving parts. The
thermal storage unit boasts a higher energy density than lithium-ion batteries
 Website: http://www.enermotion.com/

Oregon State University
 Oregon State University (OSU) in the USA have developed a device that turns the waste
heat from car exhaust pipes, diesel generators, factories and electrical utilities into cooling
or electricity

2
http://www.ener-g-rotors.com/nyserda-awards-725000-to-ener-g-rotors/
3
http://www.trucknews.com/news/exclusive-canadian-tech-company-designs-waste-heat-recovery-
powered-apu/1000638393/

9.  They combine an ORC system with a vapor compression cooling cycle. This combined
system can utilize waste heat or other thermal sources such as solar and geothermal to
generate power and cooling.
 The device gains much of its efficiency by using extraordinarily small micro channels which
help to better meet the performance, size and weight challenges.[
4
]
 The prototype tested under laboratory condition succeeded in turning 80 percent of the
waste heat into cooling capability. When producing electricity the system would not be as
efficient, reaching only 15 to 20 percent efficiency.
 In automotive technologies it would seamlessly fit in the setup of hybrid cars, taking waste
heat from the gasoline engine and using it not only for air conditioning but also to help
recharge the battery that powers the vehicle.
BMW
 They made a device called turbosteamer. The Turbosteamer works by harnessing the
previously wasted heat energy (from the exhaust and cooling system) of an internal
combustion engine to power a closed loop steam expansion unit connected to the
crankshaft, supplementing the standard engines power.
 Even if a car engine is only placed under moderate pressure, the water in this circuit is
heated up to a maximum of 550 degrees Celsius.
 In tests, with a 1.8 litre BMW four cylinder, power was upped by 14 hp (10 kw), torque
increased by 15 lb/ft (20 Nm), and fuel consumption was 15% more efficient.[
5
]
 It will be in mass production after 10 years and BMW working on reducing the weight from
current 50kg per circuit.
Eureka:
 Eureka heat transfer systems capture waste heat from air conditioning, refrigeration plant
by transferring the heat from the refrigerant into a specially designed water cylinder,
raising the water temperature to approximately 60 degrees centigrade.
 Eureka heat recover is designed for application including supermarkets, butcher’s shops,
bakeries, hotels, restaurants, food processors and wherever refrigeration plant is about
1kW to 400KW is operated.[
6
]
 The user can draw-off hot water at a sufficiently high temperature within minutes.
Airec AB
 They involved in business of high efficiency heat exchangers for gas and air. Airec Energy
India is distributer of products of Airec. [
7
]
 Airec specializes in Gas-to-Liquid heat exchangers. Airec’s exchanger design is optimized
for systems which either cool air or use energy from a hot gas flow

4
http://oregonstate.edu/ua/ncs/archives/2011/jun/prototype-demonstrates-success-advanced-new-
energy-technology
5
http://www.gizmag.com/go/4936/
6
http://www.cambridgeenergycentre.co.uk/pages/content/8/31/Eureka-Heat-Recovery-System---How-It-
Works
7
http://www.climatesolver.org/show.php?id=1263391

10.  Innovation: they have revolutionized the corrugated shape of the metal plates inside
exchangers to make them extremely compact yet highly efficient. Airec heat exchangers
are based on the brazed design and unique plate patterns for high efficiency and
compactness.
 The company’s innovative AirLight exchangers, designed specifically to be cost-effective
and optimized for air-and-water cooling systems, can increase energy efficiency and
reduce CO2 emissions by up to 30% in systems for air conditioning, freezing and
ventilation.
 Website: http://www.airec.se/
Entrans:
 Manufacture of equipment called Flexigen. Flexigen has ability for trigeneration which
combines heating, cooling and electricity generation. It is based on ORC technology and
can operates using low waste heat from 50 to 200 degree Celsius.
 It has the Ability to dynamically switch between the three operation modes to maximize
the investment and efficiency.
 They claim it to have economic lifetime of 20 years and power output between 50-
500kWel and 150-3000kWcooling. For each kWh of produced electric power with
FlexiGen, about 2,5 kWh fuel can be saved on average.
 Within the marine sector, fuel savings of up to 6% can be obtained.
 In conventional geothermal wells, if the temperature of the well is less than 160oC, they
are disregarded as it is not considered commercially viable to set up a geothermal plant
with these wells. But with the use of flexigen, operating between 50-220oC, flexigen
system are perfectly suited for generating electricity.
 Website: http://www.entrans.se/
Echogen Power Systems:
 Develpop techonolgy to produce electricity from waste heat using rankine cycle and
Supercritical CO2 as working fluid
 Operate across a broad temperature range of heat sources from 200°C to >536°C;
 Achieve efficiencies above 30% depending on waste heat source
 Be readily scalable to 45 MWe systems and above, and
 Use system components a fraction of the size of conventional technologies, yielding a
smaller system footprint and easier installation.
 Website: http://www.echogen.com/value-proposition.aspx
 Echogen Power Systems is a runner-up in the Energy Category of the 2011 WSJ Technology
Innovation Awards[
8
]




8
http://online.wsj.com/article/SB10001424052970203633104576623261551755704.html

11. HVAC systems

HVAC (heating, ventilation, and air conditioning) refers to technology of indoor and automotive
environmental comfort. HVAC system design is a major sub discipline of mechanical engineering,
based on the principles of thermodynamics, fluid mechanics, and heat transfer.
General understanding about HVAC systems: [
9
]
 Typical HVAC processes: Air handling units, fan coil units, exhaust fans
 Typical plumbing systems: Transfer pumps, sump pumps, water tanks
 Typical chilled water systems: Chillers, secondary pumps, HEX systems
 Field equipment: Sensors, valves, actuators, relays, variable frequency drives
Air-Conditioning industry is of 9,400-crore. Air-conditioning penetration is expected to grow from
3% in 2009 to 5% by 2015.
Total building space in India will increase from 8 billion square meters in 2005 to 41 billion by
2030.
McKinsey & Company report (2009), 80 percent of the India of 2030 is yet to be built.
The buildings sector accounted for the largest share (169 Mtoe or 47%) of India’s final energy use
between 1995 and 2005 (IEA 2007).
Trends in HVAC
Variable Capacity Compressors: reduced energy consumption, which may be up to 40%.
Modulates mass flow of refrigerant from 10% to 100%, Keeps the coil cold for longer periods of
time improving humidity control. [
10
]
Modulating reheat for humidity control: The part load efficiency of equipment with a modulating
compressor can be up to 35% more efficient than equipment with a standard on-off compressor
and hot gas bypass.[
11
]
Higher efficiency fans: Forward curve fans, backward incline fans
Direct Drive Fans: No belt service, reduced maintenance, No belt vibration and noise, No belt
losses, higher efficiency, Reduced bearing stress, No belt dust, residue.

9
http://www.price-hvac.com/Media/trainingModules.aspx
10
http://www.eurocooling.com/public_html/articleembraco.pdf
11
http://www.aaon.com/Documents/Featured/ModulatingCompressor_110914.pdf

12. Construction improvements, System types: Better insulating materials, dual path systems,
rooftop.
Advancements in sensors for diagnostics and inspection purpose. Continuous calculation of
energy consumption
Liquid desiccant dehumidification
Technologies involved:
Vapour compression Cycle

Vapour absorption Cycle

13. Solid-Vapour Adsorption Cooling

Value proposition
7AC Technologies:
 develops Ultra Efficient Liquid Desiccant HVAC systems for Commercial and Industrial (C&I)
buildings
 Lower the operating costs of commercial buildings for heating and cooling by 50 to 75
percent by using a strong saline solution (a desiccant) for moisture removal.
 Has less than a 1 year payback period when powered with natural gas or with a small
conventional chiller. [
12
]
 Website: http://www.7actech.com/
Chromasun:
 Chromasun’s device is 75 percent efficient. 10 * 4 foot sealed box --a utility scale solar
thermal plant and a utility-scale concentrating solar PV plant in miniature.
 The heat – roughly 65 percent of the power generated – gets exploited to run the air
conditioners while the PV-generated electricity is used locally to offset grid
 Test conducted in Bangalore concluded that Chromasun’s PVT-based CHP (Combined Heat
and Power) can be grid-competitive without government subsidies.[
13
]
 Website: http://www.chromasun.com/

12
http://energy.gov/americas-next-top-energy-innovator/7ac-technologies-inc
13
http://cleantechnica.com/2011/12/14/chromasun-harvests-suns-heat-photons-with-hybrid-
concentrated-solar-photovoltaic-thermal-modules/

14. Save Energy Systems: USA based (commercial)
 Their device Demand limiting controller (DLC) remotely manages units, minimizes
electrical use and provides HVAC service contractors feedback on performance.
 The Demand Limiting Controller (DLC) attacks the three charges for electricity: demand,
peak rate, and use.
14

 Pricing for the DLC starts at $3,399, provide potential HVAC energy savings of 30%
 The DLC is designed for commercial buildings of 6,000 square feet or more.
 Website : http://www.SaveEnergySystems.com
Regenergy365: USA based (commercial building, industrial)
 Patented exhaust energy recovery technology to significantly reduce the intense operating
costs of commercial and industrial HVAC/refrigeration systems by capturing waste air flow
(exhaust) expelled by HVACR systems to generate on-site electricity. [
15
]
 The Patented technology is referred to
as E.C.E.R.D.™ (Exhaust Capturing Electrical Regeneration Devices).
 Not much information is given about payback, price structure but this startup was listed a
semifinalist in Clean Tech Open competition.
 Website: http://www.regenergy365.com/technology.html

Energy Recovery Technologies, LLC (USA based)
 Commercializing High Efficiency Energy Recovery Ventilation (HE-ERV) systems that save
commercial and residential building owners 50% of their HVAC related energy costs.[
16
]
 Provide solution for the recovery of heat and moisture from exhaust air resulting in
inadequate efficiencies, trouble prone operations and unreliability.
 Efficiency:90% ,payback period:1 year, also has web enabled monitoring
 Website: http://www.energyrecoverytechnologiesllc.com
EcoFactor:
 Provides software-as-a-service system which uses a home’s wireless thermostat and
broadband Internet connection to regulate temperature
 EcoFactor delivers monthly reports to subscribers documenting its savings, provides web
and mobile interfaces that allow consumers to program
 System can save users up to 30 percent in HVAC-related energy use

14
http://finance.yahoo.com/news/massachusetts-start-launches-smart-approach-134800418.html
15
http://www.geekwire.com/2012/pacific-nw-semifinalists-cleantech-open-announced/
16
http://www.ongreen.com/deal-marketplace/energy-recovery-technologies-0

15.  Website: http://www.ecofactor.com
Optimum Energy:
 OptimumVAV™ is software developed to regulate air flow while using less fan power, less
chilled water and less heating energy to meet temperature.
 OptimumVAV uses demand-based relational control to reduce the amount of work
performed by central air handler fans which force air through the building to meet
temperature, humidity and CO2 or airflow requirements.
 Website: http://optimumenergyco.com/solutions/software-solutions/optimumtrav/
Clean urban energy:
 Software as a service (SaaS) platform features an automated, scalable, energy-
optimization system that exploits the thermal mass of commercial office buildings to make
buildings more energy efficient.
 Its HVAC optimization software on average achieves 10% energy savings, 20% energy
expense savings and up to 30% peak demand reduction.
 Tested on The United Building which is a 50-story, 960,000 ft²office building located in the
Chicago Loop. And results are Reduced HVAC energy expense by up to 20%.Reduced on-
peak energy usage by up to 30%.Reduced monthly peak demand expense by up to
30%.Improved chiller efficiency. Improved tenant comfort. [
17
]
 Website: http://www.cleanurbanenergy.com









17
http://www.cleanurbanenergy.com/assets/documents/United%20Case%20Study%20120425.pdf

16. Appendix 1:

17. Appendix 2

18. Appendix 3