Representative illustration of a ductless mini-split
Representative · ductless mini-split
Representative illustration — ductless mini-split (not the exact unit)
InfinityLiving · EZ Series

InfinityLiving EZ-48Z-M5B

ductless mini-split heat pump · ~3.5 ton (43,000 BTU/h cooling)

A ductless mini-split heat pump that still moves 2× more heat than the power it draws at 5°F.

ENERGY STAR Most Efficient Cold-climate designated Ductless mini-split Residential R-454B
COP at 5°F

Buy this system

Sold through HVAC contractors

This unit isn't stocked for DIY online. It's installed by a licensed pro, who also handles the refrigerant charge, permit and warranty. Get a few local quotes so you can compare the installed price.

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At a glance

Who it's for

Homes in cold climates that want to heat with a heat pump instead of gas or oil.

The standout number

COP 2 at 5°F — it keeps working efficiently when it's frigid.

The catch

Sold through contractors, so the installed price depends on local labor — get a few quotes.

The Verified Label — every certified spec

Verified LabelCertified performance & real operating cost
AHRI ref 216980917
certified 2025-03-04
status: Active

Efficiency ratings — source: AHRI / ENERGY STAR

SEER2 cooling seasonal efficiency20
EER2 cooling at 95°F, steady-state12
HSPF2 heating seasonal efficiency10.5

Capacity & the cold-climate truth — source: AHRI

Cooling capacity at 95°F outdoor43,000 BTU/h · ~3.5 ton
Heating capacity at 47°F outdoor47,000 BTU/h
Heating capacity at 17°F outdoor37,800 BTU/h
Heating capacity at 5°F the cold-climate truth — does it still heat when it's frigid?37,000 BTU/h
COP at 5°F heat moved per unit of power, at 5°F

Operating cost — computed by Verified HVAC Data

Heating cost

$17.93

per MMBtu of delivered heat, at U.S. average electricity prices

Vs. electric resistance

68%

cheaper to run than baseboard / strip heat ($55.19/MMBtu)

Computed from this unit's HSPF2 × EIA U.S. average electricity price. Your local price changes the answer — run it with your rates →

Refrigerant, staging & identity

RefrigerantGWP ≈ 466 (IPCC)R-454B
Compressor stagingContinuously variable
Cold-climate designationENERGY STAR Cold Climate
ENERGY STARMost Efficient
Outdoor modelEZ-48Z-M5B
SegmentResidential
AHRI reference #216980917

How it ranks

Where this unit sits among the 12,239 heat pumps we track, on the two numbers that decide a heat pump. Percentiles are computed from our corpus (higher = better).

COP at 5°F

Better than 55%

of the 11,972 units with a published COP at 5°F

HSPF2

Better than 81%

of the 11,928 units with a published HSPF2

Rebates & incentives

This unit meets ENERGY STAR Most Efficient — the tier many state and utility heat-pump rebates require. The federal 25C tax credit expired on December 31, 2025; the live money now is state and utility programs plus HEEHRA. Check what applies where you live on our rebates page.

Compare similar heat pumps

Frequently asked questions

Does the InfinityLiving EZ-48Z-M5B still heat in cold weather?

At 5°F it runs at a COP of 2, meaning it delivers 2 units of heat for every unit of electricity it uses. Its certified heating output at 5°F is 37,000 BTU per hour. It carries the ENERGY STAR Cold Climate designation.

What does the InfinityLiving EZ-48Z-M5B cost to run?

About $17.93 per MMBtu of delivered heat at the U.S. average electricity price, roughly 68% less than electric resistance heat. Your local electricity price changes the number — use our operating-cost calculator to run it with your rate.

What refrigerant does the InfinityLiving EZ-48Z-M5B use?

R-454B, which has a global-warming potential (GWP) of about 466. This is one of the lower-GWP refrigerants replacing R-410A.

Where can I buy the InfinityLiving EZ-48Z-M5B?

InfinityLiving sells this line through HVAC contractors rather than DIY retail, so the way to buy it is to get installed quotes from local pros. Compare the installed price, not just the equipment price.

Sources. Performance ratings from the AHRI Directory (cited by reference number 216980917; not a verbatim mirror) and ENERGY STAR certification data. Operating-cost ($/MMBtu), savings and percentile figures are computed by Verified HVAC Data from published ratings and EIA U.S. average energy prices — see our methodology. Refrigerant GWP is the IPCC value for that refrigerant. We publish no star ratings and take no payment for placement. "Not published" means the source registry doesn't disclose it — we never fill a spec with a guess.

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