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Mitsubishi Mini-Split Decision - Moisture Removal Rate FH09na versus FH12na
SuperJ
Member Posts: 609
I'm trying to decide which mini-split heat pump to install. My options are basically the 9000btu/hr and 12,000btu/hr Mitsubishi mini-splits. Because of the low min-capacity on both units I don't think the slight oversize of the 12,000btu unit will be a problem (its min is 2500btu/hr).
The FH09na should serve my needs load wise and is slightly more efficient than the FH12na (30seer instead of 26).
But it's moisture removal rate is almost a third of the FH12na (0.6pints/hr versus 1.6pints/hr FH12na). I'm guessing this is because the max cfm is similar (328cfm/342cfm) despite the FH09 being 25% smaller capacity wise, meaning the discharge air temp at design conditions will be a bit warmer on the FH09.
My question is does this balance out at lower loads? Or will the expansion valve keep the discharge temperature higher all the time on the FH09? Since the fan speed can automatically modulate, will the real world dehum capability be pretty similar? Min cooling is 1700btu on the FH09 and 2500btu/hr on the FH12na. So they both have great turn done to keep running (and dehumidifying at lower loads).
Another way of asking this does the sensible heat ratio bias towards latent as the unit unloads, or is it pretty constant throughout the modulation range?
The FH09na should serve my needs load wise and is slightly more efficient than the FH12na (30seer instead of 26).
But it's moisture removal rate is almost a third of the FH12na (0.6pints/hr versus 1.6pints/hr FH12na). I'm guessing this is because the max cfm is similar (328cfm/342cfm) despite the FH09 being 25% smaller capacity wise, meaning the discharge air temp at design conditions will be a bit warmer on the FH09.
My question is does this balance out at lower loads? Or will the expansion valve keep the discharge temperature higher all the time on the FH09? Since the fan speed can automatically modulate, will the real world dehum capability be pretty similar? Min cooling is 1700btu on the FH09 and 2500btu/hr on the FH12na. So they both have great turn done to keep running (and dehumidifying at lower loads).
Another way of asking this does the sensible heat ratio bias towards latent as the unit unloads, or is it pretty constant throughout the modulation range?
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