It comes down to the layout and how the suite is zoned. Two fan coils let the sleeping area and the living area run as separate zones, so one person can sleep cool while another keeps the living room warm, and two smaller units serving two zones tend to run more quietly than one unit pushing air across a whole suite. Because the per unit rate drops when there are two on the agreement, the second fan coil adds about $22 a month rather than doubling the cost. The Realm sales team confirms the exact count for your suite before you sign anything.