NEEA NBI RTU Projects Review RTUG Nov 8, 2012 AirMax Indirect/Direct evap RTU-Idaho –3 gen unit (2 nd gen IDEC/Dx hybrid) –Add-on to existing 5 ton RTU Variable Rate RTU Test (VRTUT) 5-ton RTUs NBI-L in Vancouver, WA + Fred Meyer-2 Idaho locations Trane Precedent Daikin McQuay Rebel AAON RQ RTU physical model

Evaporative IDEC RTU Cooling Research Overview Project installation – Bigelow Tea facility in Boise Idaho: long term field site for NEEA Summer 2012 – good data for Aug/Sept Savings projections: 50%(2,400 kWh/yr); 60% (3.6 kW) Final report December Potential to test next generation evap. unit summer 2013

AirMax IDEC Product 4 th Gen Unit Blower change: from external rotor motor 960 W single- 0.5 inch ) to 1.1 kW blower internal rotor 3-speed ( inch or inch ) Changed blower wheel from 450 mm with 130mm depth to 478mm with 170mm depth backward curve blower Control board changes: –Added LCD to replace dipswitches –Runs the economizer or direct or direct /indirect as a 3-stages unit which saves water usage –Increased purge system control accuracy –TruPsych™ control board fully integrated into the cabinet –Water coil and water pump redesigned completely to allow 100% winter drain down –Standard’ beige cabinet color

IDEC Evaporative Project Compressor Cooling Mo de

Evaporative Cooling Mode

IDEC Evaporative Savings Potential Topic 1

VRTUT Topic 1 Three high efficiency (code and better) units tested at NBI Lab, now in field measurement in Idaho The best performance was associated with the most efficient fan use Short cycling losses not relevant if timed fan is used ClimaCheck refrigeration diagnostics added

VRTUT-Typical Duty Cycle (Trane) Topic 1 Typical fan power ~ W No short cycle loss if constant vent fan on

VRTUT-Rebel Duty Cycle Topic 1 Typical supply fan power ~130 W Most energy savings from low fan power

VRTUT- Comparison of 3 RTUs Topic 1 Daikin McQuay Rebel performed about 30% better than base case (CAV-only) AAON RQa performed worse than base case when excessive supply fan power was used AAON RQb performed slightly better than base case when supply fan power was minimized

RTU Physical Model Topic 1 NBI-L is closer to a ‘Field Site Lab’ with the capability of simulating constant internal loading and measuring thermal output necessary to develop an RTU model RTU model uses inputs derived from published unit label data and unit site conditions The conditioned space can be described by two parameters: internal loading parameter (BTU/day) temperature dependency parameter (BTU/deg day)

Physical Model Input Parameters Topic 1 Nominal unit size, tons Neutral temperature COP at neutral temp Airflow, lbs/minute Fixed supply fan run, hours Fixed supply fan power, W Standby power, W Fan Power during compressor, W Economizer effect, 0 to 100% Minimum OSA fraction, % full flow Thermal effect at space, BTU/deg day Space gain, BTU/day

Physical Model - Data Fit Topic 1

Physical Model Main Energy Components Topic 1

Projects Staff Topic 1 NBI Mark Cherniack Howdy Reichmuth Dan Harris Mark Lyles Adam Sherba Idaho Design Lab Brad Acker