Model
Sub-Zero DEC3650R**/*
Rank #557 means 556 of the 1,000 refrigerator models we track cost less to run each year; the 97th efficiency percentile means it uses less energy for its size than 97% of those models.
What does the Sub-Zero DEC3650R**/* cost to run per year?
At $67 a year to run, the Sub-Zero DEC3650R**/* sits close to the middle of its class on cost, ranking #557 of 1,000 refrigerator models we track. It uses 10% less energy than the U.S. federal standard model in its class, which would cost about $75/yr to run, a saving of roughly $8 a year. Once capacity is factored in, it outperforms 97% of the refrigerator models we track on efficiency, near the very top of the normalized ranking. Its listing marks it counter-depth, meaning it sits nearly flush with surrounding cabinets rather than protruding a few extra inches like a standard-depth model; that shallower body usually means less interior volume for the same footprint.
Immediately around it on the leaderboard, the Sankey RF 1963 SS at $67/yr runs a little cheaper and the Vissani MDTF18WHRES4 at $67/yr runs a little more, a sense of how tightly models are packed at this point in the ranking. A refrigerator typically stays in service for somewhere around 12 years; over that span, the Sub-Zero DEC3650R**/*'s $67/yr adds up to roughly $804 in electricity alone, before purchase price or repairs.
By the numbers
The Sub-Zero DEC3650R**/* normalized against its whole class, so each figure means something.
What it costs you over time
Running cost is an every-year number, so it compounds. At $67/yr, here is what the Sub-Zero DEC3650R**/* adds up to before purchase price, water, or repairs enter the math.
Left running for a decade at today's US average rate, the Sub-Zero DEC3650R**/* costs about $670. That is roughly $80 less than a standard model in its class, which would run closer to $750 over the same ten years.
How the Sub-Zero DEC3650R**/* compares
The refrigerator class we track runs from $8 to $149 a year. At $67/yr, it runs about $3 a year above the class median of $64, and it is about $59 a year more than the cheapest refrigerator to run at $8. Against the US federal standard model for its class at about $75/yr, the Sub-Zero DEC3650R**/* uses 10% less energy.
What drives its running cost
At 21.7 cu ft, the Sub-Zero DEC3650R**/* is a large refrigerator for its class, which spans 1.2 to 31.7 cu ft with a median of 12.6 cu ft, size is usually the single biggest lever behind a running-cost figure, and at this end of the range there is more capacity to service, which tends to push the number up.
- Counter depth vs standard depth. Counter-depth models sit flush with cabinets but usually hold less interior volume than a standard-depth model of the same width, which can nudge the per-cubic-foot running cost either way.
- Interior volume. Cubic feet of interior volume is the first thing that scales a fridge's running cost up or down, before compressor quality even enters the picture.
- Compressor technology. Newer variable-speed (inverter) compressors modulate output instead of cycling fully on and off, which tends to use less energy for the same cooling job than an older fixed-speed compressor.
- Placement and ventilation. A fridge pushed tight against a wall or cabinet, or standing next to an oven or in direct sun, works harder to shed the heat its compressor produces, which can push real-world cost above the published figure.
Common questions
Is the Sub-Zero DEC3650R**/* cheap to run?
It is about average. At $67 a year it ranks #557 of 1,000 refrigerator models we track, close to the middle of its class on running cost.
How much does the Sub-Zero DEC3650R**/* cost per month?
Roughly $5.6/mo, spreading the $67/yr estimate evenly across twelve months at $0.1856/kWh. Actual monthly bills swing with your rate and usage pattern.
How is this running-cost figure calculated?
We take the model's published annual energy use of 362 kWh from ENERGY STAR and multiply it by the US average residential electricity rate of $0.1856/kWh, giving about $67 a year. It is an electricity-only estimate and does not include purchase price, water, or installation.
How efficient is the Sub-Zero DEC3650R**/* for its size?
97th percentile once size is factored in, a fairly typical result for the class.
Cheaper to run in the same class
| Rank | Model | Cost/yr |
|---|---|---|
| 556 | Sankey RF 1963 SS18 cu ft | $67 |
| 555 | Moffat MTE18HTKBB*18.1 cu ft | $67 |
| 554 | Moffat MTE18G*****18 cu ft | $67 |
| 553 | Midea WHD-663FWE***18 cu ft | $67 |
| 552 | Midea MDRT663FGF*****18 cu ft | $67 |
Source
ES_0031863_DEC3650R**/*_09262022111806_80141551View certified refrigerator listingsENERGY STAR data as of July 2026Sub-Zero and DEC3650R**/* are used here for identification only and are not endorsements. Figures are computed by WattWise Labs from public ENERGY STAR data, not measured in our own lab.