Multi-zone is the answer when you want two to five rooms conditioned, each on its own thermostat, without putting a separate outdoor unit on the wall for every room. One condenser outside, several heads inside. The planning order matters: rooms first, heads second, outdoor unit last.
Step one: list the rooms and size each one
Size every room like a small standalone job, about 20 BTU per square foot, adjusted for sun, ceilings, and insulation. Our sizing guide walks through it. A typical outcome looks like: main bedroom 9K, two kids' rooms 6K each, living area 12K.
Step two: pick a head style per room
- Wall heads are the default: mounted high on the wall, easy to service. BLU+ wall heads run 6K to 24K; SAJA wall heads run 7K to 18K.
- Ceiling cassettes recess into the ceiling and disappear into the room. They need ceiling cavity depth and a bit more install work. Both series offer cassette options.
Step three: match the outdoor unit
Add up the head capacities and pick a condenser in that neighborhood. NG multi-zone outdoor units come in 18K, 27K, 36K, and 48K in the BLU+ Multi Zone series (R-454B), and 18K, 30K, and 36K in the SAJA Multi Zone series (R-32).
The total doesn't need to land exactly on the condenser rating. Rooms rarely peak at the same time, so running head capacity slightly above the outdoor rating is normal practice. Each condenser supports specific head combinations, so before you order, run your combo through the system builder or call us and we'll check it.
The rule you can't break
Heads and condenser must come from the same series. BLU+ runs R-454B, SAJA runs R-32, and the two refrigerants never mix on one circuit. Pick your series first, then build inside it.
Multi-zone or several singles?
Two or three rooms scattered across opposite ends of a house sometimes come out simpler as individual single-zone systems: shorter line runs, no combination rules, independent failure points. Multi-zone wins on outdoor wall space, a single electrical circuit, and install labor for rooms that cluster together. If you're on the fence, that's a phone call: (877) 811-1251.
The short version
- Size rooms individually, then pick heads, then match the condenser to the head total.
- BLU+ Multi: 18/27/36/48K outdoor, R-454B. SAJA Multi: 18/30/36K outdoor, R-32. No mixing series.
- Wall heads for simplicity, cassettes for invisibility.
- Verify the head combination with the builder or a call before ordering.
English or Spanish, Monday through Friday, 8 to 5 Pacific: (877) 811-1251.
