Nortek Reznor RHC DJL 8000, Installation, Commissioning, Servicing

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Page 12 RHC 8000 EN April 2019 D301207 Issue C
• the temperature rise of the air through the enclosure (around the tubes)
• the inlet air temperature passing over the heat exchanger.
In function of the expected minimum inlet air temperature, the minimum required
temperature rise (to avoid condensation) must be derived from the chart below).
Type H H1 Y Y2 W W1 E
8045 09 741 671 1244 1170 400 400 400
8060 12 950 880 1244 1170 400 400 400
8075 09 741 671 1844 1770 400 400 400
8075 15 1160 1070 1244 1170 400 400 400
8100 12 950 880 1844 1170 400 400 400
8125M 15 1272 1202 1844 1770 400 460 420
8150M 18 1481 1411 1844 1770 400 460 420
8175M 21 1691 1621 1844 1770 400 460 420
8200M 24 1900 1830 1846 1770 530 530 470
Example :
• expected minimum inlet temperature = -5°C
• minimum required temperature rise shown on the chart = +13°K
Table 1 indicates the heat output (kW) of the different models.
The maximum allowable airflow through the enclosure (duct channel) around the tubes can
be calculated as follows
Example 1: Tmin = 13K (with minimum inlet temperature = -5°C)
model 8100 12 at 100% heat output : 99.94kW results into Vmax = 22459m³/h
Example 2: Tmin = 13K (with minimum inlet temperature = -5°C)
model 8100 12 at 50% modulation (see table 1 ‘heat output’) : 47.48kW results into :
Remark For air heaters with modulating gas valve attention must be given to determine
the maximum allowable airflow in function of the appropriate heat input
Table 8 Duct channel & controls compartment