The Technology Behind
-22°F Performance
EVI inverter compressor technology. The same platform trusted by Carrier, Bryant, and Daikin — without the brand markup.
Why Most Heat Pumps Fail in Winter
Standard heat pumps are rated at 47°F — essentially fall weather. As temperatures drop, they lose capacity fast. By 5°F most are running at 50-60% output. By -5°F they shut off entirely, and you're back on fossil fuel backup.
| Outdoor Temp | Standard Heat Pump | Z-Pro -22°F |
|---|---|---|
| 47°F | 100% | 100% |
| 17°F | 75% | 100% |
| 0°F | 50% | 85% |
| -5°F | SHUTDOWN | 80% |
| -13°F | SHUTDOWN | 70% |
EVI Compressor Technology
Enhanced Vapor Injection (EVI) is what separates a cold-climate heat pump from a standard unit. Standard compressors recirculate refrigerant in a single stage — efficient at mild temperatures, but the compression ratio collapses in extreme cold. EVI injects additional refrigerant vapor mid-cycle, maintaining compression efficiency and heating output even at -22°F.
Why EVI Outperforms Standard Compressors
Standard compressors use a single compression stage. EVI injects additional refrigerant vapor mid-cycle — effectively a two-stage process that maintains full output even at extreme cold.
Standard Compressor
EVI Compressor (Z-Pro)
Vapor Injection Port
Mid-cycle refrigerant injection maintains compression ratio at temperatures down to -22°F. This is the core technology that separates cold-climate heat pumps from standard units.
DC Inverter Motor
Variable-speed operation from 10-120Hz. Matches exact heating demand instead of cycling on/off. Higher efficiency, less wear, quieter operation.
Electronic Expansion Valve
Precision refrigerant metering responds in real-time to load changes. Maintains optimal superheat across all conditions for maximum efficiency.
R454B Refrigerant
Next-generation low-GWP refrigerant. 78% lower global warming potential than R410A. Meets 2025+ EPA requirements ahead of schedule.
Performance vs. The Competition
How the Z-Pro -22°F series stacks up against every major cold-climate brand on the market.
| Brand | Min Temp | Output at -13°F | Refrigerant | Warranty | Price Tier |
|---|---|---|---|---|---|
| Mitsubishi Hyper Heat | -13°F | ~100% | R32 | 12yr | Premium ($$$) |
| Daikin Aurora | -13°F | ~100% | R32 | 12yr | Premium ($$$) |
| Carrier Infinity | -22°F | 100% | R454B | 10yr | Premium ($$$) |
| Cooper & Hunter | -22°F | 100% | R32 | 5yr | Mid ($$) |
| LG Artcool | -13°F | ~95% | R32 | 10yr | Premium ($$$) |
| Bosch Climate 5000 | -13°F | ~90% | R32 | 10yr | Mid ($$) |
| Zero Z-Pro | -22°F | 100% | R454B | 12yr | Value ($) |
Zero Z-Pro uses the same EVI inverter platform as leading premium brands — manufactured on the same production lines used by global OEM suppliers to Carrier and Bryant.
AHRI Certified Performance
Every Z-Pro model is tested and certified by the Air-Conditioning, Heating, and Refrigeration Institute — the same independent lab that certifies Carrier, Trane, and Lennox.
Independent Lab Testing
Performance ratings verified by AHRI-accredited third-party laboratories. No inflated specs.
Mass Save Eligible
AHRI certification qualifies Z-Pro systems for Mass Save, NYSERDA, and other utility rebate programs.
Submittal Packages Available
Full engineering submittals with AHRI reference numbers for permit applications and inspections.
Four Head Types. Every Application Covered.
Z-Pro outdoor units support up to 6 zones from one condenser with no branch boxes. Mix and match any combination of head types.
Wall Mount
6K–36K BTU- The go-to for bedrooms and living spaces
- Mounts 7 feet up, horizontal discharge
- Quiet as 22dB — won't disturb sleep
- Quick install — 2-3 hours per head
4-Way Ceiling Cassette
9K–48K BTU- Best for commercial and open-plan spaces
- Recessed into drop ceiling — nearly invisible
- 360° airflow covers up to 1,200 sq ft from one unit
- Requires drain line to condensate pump or gravity drain
1-Way Ceiling Cassette
6K–18K BTU- Ideal for corridors and long narrow spaces
- Directional single-discharge airflow pattern
- Low profile — works with existing 2x2 T-bar grid
- Compact footprint for tight ceiling cavities
Floor Console
9K–18K BTU- Floor-level installation — no high mounting required
- Excellent for floor-to-ceiling windows and basements
- Great for rooms with limited wall space
- Easy access for filter maintenance
Faster to Install. Easier to Commission.
Z-Pro systems are designed for contractors who value their time. Standard tools, standard fittings, no proprietary headaches.
Mount & Connect
Bracket mounts in 15 min. Line set connects with flare fittings — standard 1/4" and 3/8" for most sizes. No special tools, no brazing required on pre-charged lines.
- Standard flare connections
- Pre-charged line sets available
- Universal mounting brackets
Wire & Configure
208-230V single phase for residential, 460V 3-phase available for commercial. Communication wire between indoor and outdoor units — no gateway boxes or proprietary controls.
- Standard electrical — no special circuits
- 2-wire communication bus
- DIP switch or app commissioning
Vacuum & Charge
Pull vacuum to 500 microns, release factory charge. System self-tests on power-up. Full commissioning in under 4 hours for a single-zone install.
- Factory pre-charged outdoor units
- Auto-addressing for multi-zone
- No branch boxes required
- Built-in diagnostics on first run
Ready to Stock Zero?
Get contractor pricing on the full Z-Pro -22°F lineup. Same technology, fraction of the cost.
Request Contractor Pricing