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Title: Development of a High Latent Effectiveness Energy Recovery Ventilator with Integration into Rooftop Package Equipment

Abstract

This Final Report covers the Cooperative Program carried out to design and optimize an enhanced flat-plate energy recovery ventilator and integrate it into a packaged unitary (rooftop) air conditioning unit. The project objective was to optimize the design of a flat plate energy recovery ventilator (ERV) core that compares favorably to flat plate air-to-air heat exchanger cores on the market and to cost wise to small enthalpy wheel devices. The benefits of an integrated unit incorporating an enhanced ERV core and a downsized heating/cooling unit were characterized and the design of an integrated unit considering performance and cost was optimized. Phase I was to develop and optimize the design of a membrane based heat exchanger core. Phase II was the creation and observation of a system integrated demonstrator unit consisting of the Enhanced Energy Recovery Ventilator (EERV) developed in Phase I coupled to a standard Carrier 50HJ rooftop packaged unitary air conditioning unit. Phase III was the optimization of the system prior to commercialization based on the knowledge gained in Phase II. To assure that the designs chosen have the possibility of meeting cost objectives, a preliminary manufacturability and production cost study was performed by the Center for Automation Technologiesmore » at RPI. Phase I also included a preliminary design for the integrated unit to be further developed in Phase II. This was to assure that the physical design of the heat exchanger designed in Phase I would be acceptable for use in Phase II. An extensive modeling program was performed by the Center for Building Performance & Diagnostics of CMU. Using EnergyPlus as the software, a typical office building with multiple system configurations in multiple climatic zones in the US was simulated. The performance of energy recovery technologies in packaged rooftop HVAC equipment was evaluated. The experimental program carried out in Phases II and III consisted of fabricating and testing a demonstrator unit using Carrier Comfort Network (CCN) based controls. Augmenting the control signals, CCN was also used to monitor and record additional performance data that supported modeling and conceptual understanding. The result of the testing showed that the EERV core developed in Phase I recovered energy in the demonstrator unit at the expected levels based on projections. In fact, at near-ARI conditions the core recovered about one ton of cooling enthalpy when operating with a three-ton rooftop packaged unit.« less

Authors:
; ; ;
Publication Date:
Research Org.:
United Technologies Research Center
Sponsoring Org.:
USDOE
OSTI Identifier:
886847
DOE Contract Number:
FC26-01NT41254
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; AIR CONDITIONING; AUTOMATION; COMMERCIALIZATION; ENERGY RECOVERY; ENTHALPY; HEAT EXCHANGERS; MARKET; MEMBRANES; MONITORS; OFFICE BUILDINGS; OPTIMIZATION; PERFORMANCE; PRODUCTION; TESTING

Citation Formats

Gregory M. Dobbs, Norberto O. Lemcoff, Frederick J. Cogswell, and Jeffrey T. Benolt. Development of a High Latent Effectiveness Energy Recovery Ventilator with Integration into Rooftop Package Equipment. United States: N. p., 2006. Web. doi:10.2172/886847.
Gregory M. Dobbs, Norberto O. Lemcoff, Frederick J. Cogswell, & Jeffrey T. Benolt. Development of a High Latent Effectiveness Energy Recovery Ventilator with Integration into Rooftop Package Equipment. United States. doi:10.2172/886847.
Gregory M. Dobbs, Norberto O. Lemcoff, Frederick J. Cogswell, and Jeffrey T. Benolt. Wed . "Development of a High Latent Effectiveness Energy Recovery Ventilator with Integration into Rooftop Package Equipment". United States. doi:10.2172/886847. https://www.osti.gov/servlets/purl/886847.
@article{osti_886847,
title = {Development of a High Latent Effectiveness Energy Recovery Ventilator with Integration into Rooftop Package Equipment},
author = {Gregory M. Dobbs and Norberto O. Lemcoff and Frederick J. Cogswell and Jeffrey T. Benolt},
abstractNote = {This Final Report covers the Cooperative Program carried out to design and optimize an enhanced flat-plate energy recovery ventilator and integrate it into a packaged unitary (rooftop) air conditioning unit. The project objective was to optimize the design of a flat plate energy recovery ventilator (ERV) core that compares favorably to flat plate air-to-air heat exchanger cores on the market and to cost wise to small enthalpy wheel devices. The benefits of an integrated unit incorporating an enhanced ERV core and a downsized heating/cooling unit were characterized and the design of an integrated unit considering performance and cost was optimized. Phase I was to develop and optimize the design of a membrane based heat exchanger core. Phase II was the creation and observation of a system integrated demonstrator unit consisting of the Enhanced Energy Recovery Ventilator (EERV) developed in Phase I coupled to a standard Carrier 50HJ rooftop packaged unitary air conditioning unit. Phase III was the optimization of the system prior to commercialization based on the knowledge gained in Phase II. To assure that the designs chosen have the possibility of meeting cost objectives, a preliminary manufacturability and production cost study was performed by the Center for Automation Technologies at RPI. Phase I also included a preliminary design for the integrated unit to be further developed in Phase II. This was to assure that the physical design of the heat exchanger designed in Phase I would be acceptable for use in Phase II. An extensive modeling program was performed by the Center for Building Performance & Diagnostics of CMU. Using EnergyPlus as the software, a typical office building with multiple system configurations in multiple climatic zones in the US was simulated. The performance of energy recovery technologies in packaged rooftop HVAC equipment was evaluated. The experimental program carried out in Phases II and III consisted of fabricating and testing a demonstrator unit using Carrier Comfort Network (CCN) based controls. Augmenting the control signals, CCN was also used to monitor and record additional performance data that supported modeling and conceptual understanding. The result of the testing showed that the EERV core developed in Phase I recovered energy in the demonstrator unit at the expected levels based on projections. In fact, at near-ARI conditions the core recovered about one ton of cooling enthalpy when operating with a three-ton rooftop packaged unit.},
doi = {10.2172/886847},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2006},
month = {Wed Mar 01 00:00:00 EST 2006}
}

Technical Report:

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  • This report summarizes the investigation of two active desiccant module (ADM) pilot site installations initiated in 2001. Both pilot installations were retrofits at existing facilities served by conventional heating, ventilating, and air-conditioning (HVAC) systems that had encountered frequent humidity control, indoor air quality (IAQ), and other operational problems. Each installation involved combining a SEMCO, Inc., ADM (as described in Fischer and Sand 2002) with a standard packaged rooftop unit built by the Trane Company. A direct digital control (DDC) system integral to the ADM performed the dual function of controlling the ADM/rooftop combination and facilitating data collection, trending, and remotemore » performance monitoring. The first installation involved providing preconditioned outdoor air to replace air exhausted from the large kitchen hood and bathrooms of a Hooters restaurant located in Rome, Georgia. This facility had previously added an additional rooftop unit in an attempt to achieve occupant comfort without success. The second involved conditioning the outdoor air delivered to each room of a wing of the Mountain Creek Inn at the Callaway Gardens resort. This hotel, designed in the ''motor lodge'' format with each room opening to the outdoors, is located in southwest Georgia. Controlling the space humidity always presented a serious challenge. Uncomfortable conditions and musty odors had caused many guests to request to move to other areas within the resort. This is the first field demonstration performed by Oak Ridge National Laboratory where significant energy savings, operating cost savings, and dramatically improved indoor environmental conditions can all be claimed as the results of a retrofit desiccant equipment field installation. The ADM/rooftop combination installed at the restaurant resulted in a reduction of about 34% in the electricity used by the building's air-conditioning system. This represents a reduction of approximately 15% in overall electrical energy consumption and a 12.5-kW reduction in peak demand. The cost of gas used for regeneration of the desiccant wheel over this period of time is estimated to be only $740, using a gas cost of $0.50 per therm--the summer rate in 2001. The estimated net savings is $5400 annually, resulting in a 1-2 year payback. It is likely that similar energy/cost savings were realized at the Callaway Gardens hotel. In this installation, however, a central plant supplied the chilled water serving fan coil units in the hotel wing retrofitted with the ADM, so it was not metered separately. Consequently, the owner could not provide actual energy consumption data specific to the facility. The energy and operating cost savings at both sites are directly attributable to higher cooling-season thermostat settings and decreased conventional system run times. These field installations were selected as an immediate and appropriate response to correct indoor humidity and fresh air ventilation problems being experienced by building occupants and owners, so no rigorous baseline-building vs. test-building energy use/operating cost savings results can be presented. The report presents several simulated comparisons between the ADM/roof HVAC approach and other equipment combinations, where both desiccant and conventional systems are modeled to provide comparable fresh air ventilation rates and indoor humidity levels. The results obtained from these simulations demonstrate convincingly the energy and operating cost savings obtainable with this hybrid desiccant/vapor-compression technology, verifying those actually seen at the pilot installations. The ADM approach is less expensive than conventional alternatives providing similar performance and indoor air quality and provides a very favorable payback (1 year or so) compared with oversized rooftop units that cannot be operated effectively with the necessary high outdoor air percentages.« less
  • In 1994, Wheelabrator Environmental Systems began operation at two new facilities. The Ridge Generating Station is an independent power production facility located in Polk County, FL consisting of a 45 NM, multi-fuel, steam driven electric power plant. The plant utilizes a unique mix of wood waste, shredded tires and landfill gas to fuel the steam generator. The Falls Recycling and Energy Recovery Facility, located in Morrisville, PA, has two units designed to process 750 tons per day each of municipal solid waste and generate a total of approximately 50 MW of electrical energy. Both facilities began commercial operation in Julymore » - August 1994. Each facility was designed to meet Best Available Control Technology for particulate, acid gases, metals and nitrogen oxides. The air pollution control equipment common to both facilities includes a Selective Non-Catalytic Reduction system, a two fluid nozzle Spray Dryer Absorber and a Fabric Filter. The Falls facility is also equipped with a Powered Activated Carbon injection system for additional mercury control. This paper will discuss the design philosophy of the air pollution control equipment at each site, the results of each facility`s compliance tests, the first year operating experiences and a comparison of the achieved emissions. The discussion of results will include particulate, SO{sub 2}, HCl, NO{sub X}, CO, VOC, Pb, Be, Hg and other trace metals emission measurements.« less
  • Two engineering models of high-efficiency heating sections for a commercial rooftop heating/cooling system were developed, fabricated, and evaluated. Each engineering model used a different combustion technology. A variable-rate pulse-combustion heating section operated satisfactorily over a range of 42% to 127% (96,600 to 292,000 Btu/hr) of its normal input rate of 230,000 Btu/hr. This variable rate unit exceeded program goals, which anticipated only a dual rate pulse combustion model and had a steady-state efficiency of 91.9% at 100% input rate and 97.3% at 50% input rate. A secondary heat exchanger was also successfully added to the heating section of a conventionalmore » rooftop unit employing tubular heat exchangers. This modified conventional unit had a steady-state efficiency of 93.5% at 100% input rate and 92.2% at 50% rate.« less
  • This project was undertaken to determine how much energy could be saved in the US by using high efficiency recoperators to recover heat from industrial flue gases. A mail questionnaire was sent to 1350 manufacturing firms in California and the Eastern US to obtain data on fuel consumption in plants representing 50 different Standard Industrial Classifications (SIC). Plant surveys of 16 of the most fuel-consuming firms were made, so that the potential fuel-saving with recuperators could be estimated for the operating conditions and equipment used in each plant. These data were extrapolated to predict potential savings for US industry. Themore » results indicate that an estimated 0.35 quads of energy can be recovered from industrial process thermal effluents using heat recuperators which are 85% effective. This represents 0.50% of the annual energy consumption in the US, or 4.2% of the total natural gas and fuel oil consumed by all SIC's as reported in 1974, or enough fuel to heat 5 million typical US homes. It is concluded that: the most significant fuel conservation potential of recuperators exists in the metals, glass, and cement industries where the flue gas temperature is between 1000 to 1200/sup 0/F or above 1800/sup 0/F; technical problems involved in waste heat recuperation must be solved and are related to the physical and chemical properties of the flue gas, high temperature materials needed for recuperators, and modifications to industrial equipment so that the recovered heat can be used; and, as fuel costs increase, the installation of high efficiency recuperators hassignificant economic advantages. Further federal-industry efforts to develop high performance recuperators are recommended. (LCL)« less
  • Drawings illustrating the piping and mechanical equipment of the Barstow Solar Pilot Plant are presented. (BCS)