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Community and Q&A

Multizone Compressor vs. Two Single-Unit Compressors

jgold723 | Posted in General Questions on

We’re getting estimates for mini-split heat pumps for our 1970’s split level in southern Maine. We have two proposals, each for two heads, 1 on each level. One contractor is proposing a multizone compressor, the second two single-unit compressors.

Is there an advantage to one method over the other?

Both are selling Mitsubishi products

FWIW, the two-compressor cost is lower than the multizone.

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Replies

  1. Expert Member
    PETER Engle | | #1

    One-to-one matched systems are generally more efficient than multi-head systems, because the one-to-one compressors generally have significantly better turndown ratios. The independent systems would also provide better zone control than two heads on a single compressor. With a single compressor, there is generally some refrigerant routed through the second head, even when it is not calling for heat/cold. If the one-to-one separate systems are cheaper to install, I would definitely go with that option. As always, make sure the systems are properly sized for your loads. Have a Manual J heat load analysis performed, preferably by an independent contractor. With minisplits, there is definitely a "Goldilocks" zone where proper sizing gives best energy performance and comfort.

  2. jwasilko | | #2

    1:1 systems generally have a better turndown ratio, which means they avoid short cycling. Some of them are 4.5:1 or more.

    2 1:1 systems also gets you redundancy in case of failure.

    Plus, it's cheaper. It's a win all around.

  3. mr_reference_Hugh | | #3

    1:1 for sure. If it is cheaper that is a bonus.

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