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Trouble-Free ERV. for over 20 years!. What is an Energy Recovery Ventilator (ERV). An air-to-air heat exchanger that…. … recovers energy from both heat and humidity. What makes ERV the preferred choice for schools?.
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Trouble-Free ERV for over 20 years!
What is an Energy Recovery Ventilator (ERV) An air-to-air heat exchanger that… … recovers energy from both heat and humidity.
What makes ERV the preferred choice for schools? Problems resulting from low ventilation rates have never been more evident. The demand for mechanical ventilation has never been greater.
Conventional Ventilation • Flushes Out Contaminants $ • Dries Excess Moisture • Dispels Odors • CAN COST A LOT!
What makes ERV the preferred choice for schools? ERV makes the ventilation rates needed for moisture control and good IAQ affordable. How?
EPA “Tools for Schools” “ERV reduces the peak heating & cooling loads” “ERV systems can provide annual energy savings by reducing the amount of HVAC energy needed” “Allows capital reduction due to HVAC equipment downsizing” www.epa.gov/iaq
What makes ERV the preferred choice for schools? Code requirements & mandates • Minnesota • Washington • Ohio • New Jersey Next?
Heating Season Conventional Ventilation Cold Dry Warm Humid
Less Warm Less Humid Less Dry ERV Less Cold Heating Season Energy Recovery Ventilation Cold Dry Warm Humid
Cooling Season Conventional Ventilation Hot Humid Cool Dry
Less Cool Less Dry Less Hot ERV Less Humid Cooling Season Energy Recovery Ventilation Hot Humid Cool Dry
Mechanical Wheel Systems Circumference Seal Desiccant Material Diameter Seal Blowers, Motors
PURGE AIR Mechanical Wheel Systems Outdoor Air Fresh Air Supply Room Air Exhaust Air Media Rotation
RenewAire Static-Plate Technology Cross-flow Exchange Core EV450 Blowers
World-Wide Acceptance Kuala Lumpur • Integrated in systems featuring prominent HVAC brands: Point Barrow Trane Carrier York McQuay • Developed & Patented 1970’s • First U.S. installations 1980
The Core is the Key! Transfers heat by conduction. Transfers humidity through vapor pressure differential.
EXHAUST Lower Humidity Hydroscopic Resin Medium H2O Migration Higher Humidity FRESH AIR
EXHAUST Higher Humidity H2O Migration Hydroscopic Resin Medium Either Way = Lower Humidity No liquid water No freezing FRESH AIR
Think of a magnet… Zn Fe Zn Fe Fe Pb Fe Cu Cu Fe Pb Fe Fe Zn Fe Pb Pb Fe Cu Fe Fe Cu Fe Zn Zn Fe Pb Fe Fe Pb Fe Cu Cu Fe Zn Fe Fe Zn Fe Pb Cu Zn Pb Fe Zn Fe Zn Fe Fe Pb Fe Cu Cu Fe Pb FeFe Zn Fe Pb Pb Fe Cu FeFe Cu Fe Zn Zn Fe Pb Fe Fe Pb Fe Cu Cu Fe Zn Fe Fe Zn Fe Pb Cu Zn Pb Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe
…for water vapor! O2H2O N H2OH2O Co H2O Co N H2O Co2H2O NH3 N H2O N Co2H2O N H2O H2O N H2O N Co H2O N H2OH2O N H2O CoN H2O Co2H2O H2O O2H2O NH3 Co2 O2H2O N H2OH2O Co H2O Co N H2O Co2H2O NH3 N H2O N Co2H2O N H2O H2O N H2ON Co H2O N H2OH2O N H2OCoN H2O Co2H2OH2O O2H2ONH3 Co2 H2O H2O H2O H2O H2O H2O H2O H2O H2O Hydroscopic Resin Medium
Why is RenewAire preferred over wheel products? Capital Savings Operational Savings Reliability Design Flexibility
The Problem With Wheels Air Leakage Circumference Seal Desiccant Material High Maintenance Diameter Seal Reliability Issues Blowers, Motors
PURGE AIR (10 CFM ) Lost Air EffectsMicrometl ERV-AA Rated Airflow = 500CFM Pressure = -0.5Exhaust Air Transfer = 9.9% OACF = 1.02 Wheel Cross Section Outdoor Air Fresh Air Supply 510 CFM 500 CFM Room Air Exhaust Air Media Rotation 510 CFM 500 CFM
PURGE AIR (165 CFM ) Lost Air EffectsMicrometl ERV-AA Rated Airflow = 500CFM Pressure = 0.00 Exhaust Air Transfer = 0.2% OACF = 1.33 Wheel Cross Section Outdoor Air Fresh Air Supply 665 CFM 500 CFM Room Air Exhaust Air Media Rotation 665 CFM 500 CFM
PURGE AIR (295 CFM ) Lost Air EffectsMicrometl ERV-AA Rated Airflow = 500CFM Pressure = +0.5 Exhaust Air Transfer = 0.0% OACF = 1.59 Wheel Cross Section Outdoor Air Fresh Air Supply 795 CFM 500 CFM Room Air Exhaust Air Media Rotation 795 CFM 500 CFM
“Lost Air” is Significant in Wheels • Small wheels 15-30% and still some exhaust air transfer • Small wheels over 50% to achieve 0.0 exhaust air transfer • Large wheels typically 10-20%
Fresh Air Supply 450 CFM Room Air 450 CFM Lost Air EffectsRenewAire EV450 Rated Airflow = 450 CFM Pressure = 0.0 Exhaust Air Transfer = 0.0% OACF = 1.02 Outdoor Air 459 CFM Exhaust Air 459 CFM
High Cross Contamination Low Efficiency Ventilation System Design Low Cross Contamination High Efficiency Wheel Performance - A Delicate Balance High Cross Contamination Low Efficiency Ventilation System Design Low Cross Contamination High Efficiency
Minimum Purge Air Losses = No Overbuilding of System Low Cross Contamination High Efficiency Ventilation System Design = Capital Savings
Routine Wheel Maintenance 1. Remove wheel module 2. Disassemble module 3. Recondition exchange medium 4. Adjust/replace seals 5. Adjust/replace belts or drive 6. Reassemble module 7. True wheel 8. Replace module
Wheel Maintenance Cost 2.5 hours – 8.5 hours x $70/hour (Madison, WI) $175 - $595 x 2/year $350 - $1190 per wheel!
Maintenance Downtime • Wheel stops: no energy recovery • Air-X-Change has recommended buying a replacement wheel with each unit to switch out for maintenance
Without Regular, Professional Service System Failure : 100% outside air!
RenewAire Technology • Straight Air Passages • Laminar Flow • Typical Velocity • 200 - 500 ft./ min. • Static pressure loss • 0.3 – 1.3 inch Turbulent Flow vs. Laminar Flow
Does the RenewAire core foul with particulate? Particulate mats on the low velocity entering faces of the core.
After vacuum cleaning with soft brush – airflow is fully restored
Easy Maintenance: 15 minutes @ janitorial staff hourly rate = operational savings
Reliability 10 YEAR Core Warranty • No failure • No degradation in performance
RenewAire Allows Heating Equipment Downsizing (per 1000 cfm at 0º design condition) Load imposed by OA = 150,000 BTU/hour Load imposed by RenewAire = 56,000 BTU/hour Savings with RenewAire = 94,000 BTU/hour
How can RenewAire be Applied? Distributed air schematic Rooftop Tied to central air handler
Distributed Air Application Twenty-seven EV450 units above suspended ceiling Yellow Medicine East High School, MN
Integrated ERV/Fan Coil in School Classroom (Available 277VAC option)
Integrated ERV/VAV boxin School Classroom (Available 277VAC option)
Rooftop Application Fourteen RTEC ERVs tied into Carrier and ICP roof top units Ballentine Elementary School Irmo, South Carolina
Rooftop Application End - connect or stand - alone 450 cfm – 8000 cfm HE2X900RTV