Specifications

2008 Residential Appendices RA3-24
Appendix RA3 – Residential Field Verification and Diagnostic Test Protocols
The fan flow measurement shall be performed using the following procedures; all registers shall be fully
open, and the air filter shall be installed. Turn on the system fan at the cooling speed and measure the
fan flow at the return grille(s) with a calibrated flow capture hood to determine the total system return fan
flow. The system fan flow (Qah, cfm) shall be the sum of the measured return flows.
RA3.3.3.2 - RESERVED
RA3.3.3.3 Diagnostic Air Handler Watt Draw
The sy
stem passes the Watt Draw test if the air handler watt draw is less than or equal to the value
claimed in compliance calculations and reported by the ACM on the CF-1R.For multi-zone systems the
measured air handler watt draw must be less than or equal to the value claimed in compliance
calculations and reported by the compliance software on the CF-1R. This must be accomplished with all
zones operating and without bypasses from the supply ductwork to the return ductwork.
The diagnostic air handler watt draw shall be measured using one of the following methods:
RA3.3.3.3.1 Diagno
stic Air Handler Watt Draw Using Portable Watt Meter
The air handler watt draw measurement shall be performed using the following procedures; all registers
shall be fully open, and the air filter shall be installed. Turn on the system fan at the maximum speed used
in the installation (usually the cooling speed when air conditioning is present) and measure the fan watt
draw (Wfan).
RA3.3.3.3.2 Diagnostic Air Handler Watt
Draw Using Utility Revenue Meter
The air handler watt draw measurement shall be performed using the following procedures; all registers
shall be fully open, and the air filter shall be installed. Turn on the system fan at the maximum speed used
in the installation (usually the cooling speed when air conditioning is present) and turn off every circuit
breaker except the one exclusively serving the air handler. Record the Kh factor on the revenue meter,
count the number of full revolutions of the meter wheel over a period exceeding 90 seconds. Record the
number of revolutions (Nrev) and time period (trev, seconds). Compute the air handler watt draw (Wfan)
using the following formula:
Equation RA3.3-3 Air Handler Fan Watt Draw Wfan = (Kh x Nrev x 3600) / trev
Return all circuit breakers to their original positions.