Home Performance AC Changeout w/ UltraAire SD12

The home had 3 A/C systems and was experiencing high relative humidity indoors and in the attic. A load calculation revealed that the equipment was new but severely oversized. So, the Kalos team planned to downsize the equipment, seal the attic vents, and install a dehumidifier in the attic. The UltraAire SD12 dehumidifier allows the attic’s humidity and temperature to stay under control; the SD12 has a remote condenser and removes some heat from the attic as well. As with most dehumidifiers, the SD12 does reheat the air, but it doesn’t cause a sensible increase in temperature.

Two of the Carrier Infinity condensers and the UltraAire dehumidifier condenser are on one side of the house. Each Carrier Infinity system also has an ICM493 surge suppressor to protect the units from high-voltage events (either from excess utility voltage or lightning strikes). The systems’ electrical components come together at a single disconnect.

The third Carrier Infinity condenser is on the other side of the house and has its own ICM493. Since the tubing comes out of the ground, we have covered it in corrugated tubing to protect it from lawn equipment.

As with all of our installations, we keep the liquid line filter driers indoors to prevent corrosion. An indoor liquid line filter drier is also more likely to protect the TXV from solid contaminants during cool mode testing. The condensate line has also been trapped and vented at the unit itself.

The SD12 contributes to a small decrease in supply air temperature and removes roughly 150 pounds of moisture per day. It also has ports, so you can check its functioning with apps like measureQuick (and use probes to read the supply air temperature). The dew point is very low in the attic, which is desirable.

The fully commissioned equipment ended up solving the customer’s comfort and humidity problems.