Verifying Capacity - Aprilaire 1830 Troubleshooting Manual

Verifying Capacity

If the unit is functioning properly, and there are no diagnostic codes present, this procedure can be used
if there is concern that the dehumidifier is not removing sufficient moisture. This procedure requires
that the external static pressure of the dehumidifier be known and that the user has measuring
equipment capable of measure air conditions between 50°F – 100°F, and 5% RH to 70% RH. If ducted
from the return to the supply of the HVAC system, make sure the HVAC system is not operating during
this test; the HVAC system must be on if the unit is ducted return to return. If the unit is not ducted to
the HVAC system, then it does not matter. Use the graphs and airflow performance tables provided to
convert the inlet/outlet air conditions and airflow to air moisture removal rates. If the inlet air
conditions are not within those listed on the table(s), contact Aprilaire Technical Support Monday
through Friday from 7:00 a.m. to 5:00 p.m. CST at (800) 334-6011 for assistance in determining
performance.
1. Verify that the flap damper on the outlet of the dehumidifier opens/closes freely.
2. Verify that the ductwork is free of obstructions and kinks and that the filter is clean – remove
the filter for this test if dirty.
3. Ensure that all panels are in place and assembled with screws. DO NOT REMOVE PANELS
DURING THIS TEST.
4. Adjust the control lowest setting 40% (do not put the unit in TEST mode as this will allow the
compressor to run for only one minute) to initiate a dehumidifier call. Note: If the dew point of
the air is below 40°F, the dehumidifier compressor will not turn on.
5. Measure the static pressure between the inlet and outlet of the dehumidifier and record the
corresponding airflow from the tables below (use an 1830 @ 0.20" w.c. static for example):
Table 1: Model 1830
Static Airflow
Pressure
("w.c.)
0.0
0.1
0.2
0.3
6. Allow the dehumidifier to run long enough to get a good, stable reading – 15 minutes minimum.
7. Press and hold the MODE button and UP button for 3 seconds. Use the UP or DOWN button to
scroll to and record the inlet air temperature (display shows "AIR SAMPLING" along with the
value) and RH of the inlet air.
8. Find the inlet air moisture content in Graph 1 below. Locate the inlet air temperature at the
bottom of the graph and draw a straight line up until you meet the inlet air RH curve then read
the moisture content at the left (1.31 ppd/CFM @ 80°, 60% RH for Model 1830 example shown).
11 | P a g e
Table 2: Model 1850
Static
(CFM) Pressure
("w.c.)
160 0.0
140 0.1
120 0.2
100 0.3
Table 3: Model 1870
Airflow Static
(CFM) Pressure
("w.c.)
245 0.0
230 0.1
215 0.2
200 0.3
Airflow
(CFM)
310
290
270
250