GMCC KSN89D21UER31 Rotary Compressor: Model String Decode, 8.9 cm3/rev Class Data and Selection Guide

The string KSN89D21UER31 can be read field by field against the GMCC Rotary Compressor Product Catalog 2024. KSN is a KSN line prefix, 89 is a displacement field that the catalogue prints as 8.9 cm3/rev, and the characters after the displacement carry motor, load and build information. No edition consulted publishes a rating row for the exact string, and the two field values it combines late in the string are each printed only on 9.8 cm3/rev rows.

Key facts at a glance

What does the model string KSN89D21UER31 encode?

The catalogue prints rotary model strings as a run of fields with no separators, and each field can be read against a printed example elsewhere in the same document. Six fields are visible in the strings that carry a trailing element. Reading KSN89D21UER31 against that grammar gives a KSN line prefix, an 8.9 cm3/rev displacement field, the motor letter D, a two-character load field reading 21, a three-character build field reading UER, and the trailing element 31.

The displacement field is the least ambiguous part of the string. The catalogue prints the displacement column in cubic centimetres per revolution, and every string whose two-digit field reads 89 carries 8.9 in that column rather than an adjacent value, so the mapping is direct and does not need interpolation from a neighbouring size.

Is there a published rating row for KSN89D21UER31?

No. A full-text search of the official 2024 extract, the Famco edition, the Totaline edition and a distributor catalogue mirror returns zero occurrences of the exact string, zero occurrences of the partial strings D21UER31 and KSN89D21, and zero occurrences in the site sitemap used to build this article. The exact string is therefore not a published catalogue model in any document consulted.

This is a different situation from a string that is merely absent because a catalogue omits a page. Four of the six fields are independently attested in the same document, and the two that are least common are printed on rows that sit in a different displacement band. The combination is unattested even though its parts are not.

Where does the D21 field appear in the catalogue?

The string D21 occurs on exactly two rows of the official 2024 extract, and both rows carry 9.8 in the displacement column. The first is KSN98D21UEZB31, rated 9.8 cm3/rev with 3070 W, 10475 Btu/h, 784 W input and COP 3.92. The second is KSN98D21UEZD31, given the same 9.8 cm3/rev, 3070 W, 10475 Btu/h, 784 W and 3.92 in the same table. Both sit in the refrigerant band whose head reads R 32/R410A and whose sub-head names the DC Inverter Single Cylinder and DC Inverter Twin Cylinder groups at a test condition of SEER60.

No 8.9 cm3/rev row in that band carries the field value 21. The load fields printed on the 8.9 rows of the same band are 32 and 35, and one further 8.9 row outside the band carries 53, so the value 21 does not appear anywhere in the 8.9 displacement class.

Where does the UER31 suffix appear in the catalogue?

The suffix UER31 occurs on exactly one row of the official 2024 extract. That row is KSN98D27UER31, rated 9.8 cm3/rev with 3070 W, 10475 Btu/h, 779 W input and COP 3.94. It sits in the same refrigerant band as the two D21 rows and carries the load field 27 rather than 21. The row differs from KSN98D21UEZB31 in two places only: the load field, and the input power, which falls from 784 W to 779 W while the stated capacity stays unchanged at 3070 W and the COP rises from 3.92 to 3.94.

No 8.9 cm3/rev row anywhere in the extract ends in UER31. The build fields printed on 8.9 rows that carry a D motor letter are UEZA31, UEZ3 and UEDF. The string UER31 therefore has exactly one printed home, and that home is in the 9.8 displacement band.

Why do D21 and UER31 never appear on the same string?

Across the whole official 2024 extract the two field values are mutually exclusive. D21 is printed on the KSN98D21UEZB31 and KSN98D21UEZD31 rows, which carry the load field 21 and the build field UEZB or UEZD. UER31 is printed on the KSN98D27UER31 row, which carries the load field 27 and the build field UER. The two rows that hold D21 differ from the one row that holds UER31 in both the load field and the build field, so no printed string carries both.

That is the reason KSN89D21UER31 cannot be resolved by pointing at a single catalogue row. Its displacement field places it in the 8.9 class, where the load fields printed are 32, 35 and 53. Its load field reads 21, a value the catalogue prints only in the 9.8 class. Its build suffix reads UER31, a value the catalogue prints once, also in the 9.8 class. Every field is attested somewhere in the catalogue, but the four values that matter are drawn from two displacement bands that the printed tables keep separate.

Which GMCC models does the catalogue publish at 8.9 cm3/rev?

Twelve rows in the official 2024 extract print 8.9 in the displacement column. They span six line prefixes and several motor generations, and they do not agree on capacity, input power or efficiency. The Famco edition prints fifteen such rows and the Totaline edition seventeen, so the count depends on the edition, but the membership of the official extract is stable and is what the table below records.

None of the twelve is KSN89D21UER31, and none carries the D21 field or the UER31 suffix. The D-motor rows in this class are KSK89D32UEZA31, KSK89D35UEZ3, TSK89D35UEZ3 and ASK89D53UEDF, so if a buyer is looking for a D-motor 8.9 cm3/rev compressor with published figures, those four rows are the ones the catalogue supports.

Under which operating conditions are the 8.9 cm3/rev rows measured?

The rows are not measured under one condition. Each sits under a band whose head names a refrigerant and whose sub-head names a supply and a test condition, and the bands differ from one another. Reading the neighbouring sub-heads of the official extract, the four D-motor rows sit under the band headed R 32/R410A with the DC Inverter Single Cylinder and DC Inverter Twin Cylinder groups at SEER60. The KSN89V11VEZ3 row sits under a band headed R 32 with a single-phase supply at 50Hz and 220 to 240 V, where the left sub-head gives GX as the test condition and the right sub-head gives ARI.

Because the bands differ, two rows at the same displacement are not automatically comparable. A capacity figure printed under a GX sub-head and one printed under an ARI sub-head come from different measurement regimes, and the same string printed in a different edition can carry different columns, as the next section records.

One measurement caveat applies to the rows that fall under paired sub-heads. Where a band prints two sub-heads side by side, the extract does not always make it unambiguous which of the two governs a row in the middle of the table, because the flattened column mode places the sub-head text and the row text on the same visual line. The attributions in the table above are the ones the neighbouring rows support, and a reader who needs certainty for a specific row should read the sub-head immediately above it in the source PDF rather than relying on the flattened text.

What performance spread does the 8.9 cm3/rev class cover?

The spread is wide enough that the displacement alone predicts very little. Capacity across the twelve official rows runs from 2195 W on KSM89V13UDZK to 2795 W on KSK89D32UEZA31, a spread of 600 W, or 27 per cent above the lowest figure. Input power runs from 592 W on ASM89V1VFZ to 895 W on ASN89N1UDZ. COP runs from 2.70 on KSM89V13UDZK to 4.20 on ASM89V1VFZ, and the ratio between those two figures is 1.556.

The row with the highest COP is also the row with the lowest capacity and the lowest input power, so efficiency in this class is bought by moving less refrigerant rather than by moving the same amount with less work. A buyer who fixes on the displacement value alone and then expects the highest capacity to come with the highest efficiency is reading the class backwards.

Two rows in the class are printed with the same figure in both editions used here and two are not. KSN89D22UFZ and KSN89D32UFZ appear in the Famco edition at 8.9 with 2815 W, 9605 Btu/h and 730 W for the first and 2815 W, 9605 Btu/h and 712 W for the second, while the Totaline edition prints 2782 W, 9500 Btu/h and 710 W for the first and 2650 W, 9042 Btu/h and 670 W for the second. Both rows sit under a band naming R32 with a single-phase 50Hz 220 to 240 V supply and ARI as the test condition in each edition, so the divergence is not explained by a different stated condition. It is recorded here as an open item rather than resolved.

Which applications and refrigerants does this class suit?

The 8.9 cm3/rev class is an air-conditioning displacement group. The bands that govern its rows name R 32, R410A and, on one band, R 22 alongside R 32. R 32 is a mildly flammable refrigerant, and a system built around it has to satisfy the charge limits, ventilation and leak-detection rules that apply to that classification rather than treating the choice as a compressor-only decision. The D-motor rows in the class are named as DC Inverter Single Cylinder and DC Inverter Twin Cylinder groups, which places them in variable-speed residential and light commercial air conditioning rather than in fixed-speed equipment.

The catalogue also separates its air-conditioner sections from its freezing sections, and the 8.9 rows sit in the air-conditioner sections. A buyer who needs a low-temperature compressor should not read the 8.9 class as a candidate for that duty on the strength of displacement alone.

What should a selection brief specify?

A brief that gives only the displacement value is not enough to select from this class, because twelve published rows share the displacement and differ by up to 600 W in capacity and by a factor of 1.556 in COP. A workable brief names the refrigerant, the supply, the test condition the capacity figure is quoted against, and the capacity itself, and it states whether the compressor is to be fixed speed or inverter driven. The D-motor rows in this class belong to the inverter groups, so a fixed-speed requirement and a D-motor requirement cannot both be met by the same rows.

If the exact string KSN89D21UER31 is the requirement, the brief cannot be answered from published data at all, and the correct step is to ask the supplier or the manufacturer for a rating sheet that names the full model string. A sheet that names a shorter string, or that names the displacement class without the load field and build field, does not answer the question.

What are the selection advantages of this displacement class?

The advantages are breadth and availability rather than a single standout figure. Twelve published rows share the displacement, which means a system designer can move within one envelope across a capacity range of 600 W and a COP range from 2.70 to 4.20 without changing the compressor footprint class. Four of the twelve rows carry the D motor letter and sit in the inverter groups, so a variable-speed design has published options at this displacement. The best published COP in the class, 4.20 on ASM89V1VFZ, is achieved with the lowest published input power in the class, 592 W, which suits designs where supply loading matters as much as capacity.

The class also carries a cost in ambiguity. Two rows of the class are printed with different figures in two editions of the same manual, and the class contains rows under four different test-condition sub-heads. A designer who compares two rows without checking their sub-heads will compare figures that were not measured the same way. The practical advantage is therefore conditional: the class is well populated, and it rewards a buyer who reads the condition line before the number.

Which related GMCC rotary compressor models does this supplier list?

The models below are taken from this supplier's own product page URLs rather than from catalogue rows, and each listing page carries its own specification table, which is the authority for that model. No displacement, capacity, Btu/h, input or COP figure is asserted for any of them here.

Two of the six designations sit in the 8.9 cm3/rev displacement class used above, KSK89D59UEZC and KSM89V1VDZ, and one sits in the KSN line. The remaining three fall outside this displacement class and are listed because they are the same product family on the same site.

Frequently asked questions

Is KSN89D21UER31 a real GMCC model?

It does not appear as a published catalogue model in any document consulted, and the exact string returns zero occurrences. Its fields are individually attested, but the combination is not printed. The supplier maintains an editorial and technical content index alongside its product pages.

What displacement does the 89 field indicate?

The catalogues this article relies on print the displacement column in cubic centimetres per revolution. Every string whose two-digit field reads 89 carries 8.9 in that column, so the field reads 8.9 cm3/rev.

Can capacity be quoted for KSN89D21UER31?

No. No rating row exists for the exact string, so there is no published capacity, Btu/h value, input power or COP that belongs to it. Any figure offered for this string would have to come from a different model.

Where is the D21 field printed in the catalogue?

On two rows of the official 2024 extract, KSN98D21UEZB31 and KSN98D21UEZD31. Both carry 9.8 cm3/rev, 3070 W and 10475 Btu/h.

Where is the UER31 suffix printed in the catalogue?

On one row of the official 2024 extract, KSN98D27UER31, which carries 9.8 cm3/rev, 3070 W and 10475 Btu/h.

Which refrigerant applies to this class?

The class is not tied to one refrigerant. The D-motor rows sit under a band headed R 32/R410A, one further band is headed R 32 alone, and one band names R 22 alongside R 32. System design must address the charge limits and leak-detection rules that follow from the chosen refrigerant rather than treating refrigerant selection as a compressor-only decision.

Why do two rows with the same displacement show different COP?

Because they are not measured under the same sub-head. Across the class the sub-heads in use include GX, ARI, ASH and SEER60, and a capacity figure printed under one is not directly comparable with a figure printed under another.

Does a higher load field mean higher capacity?

Not in a way that can be relied on from the load field alone. The 8.9 cm3/rev rows carry the load fields 32, 35 and 53, and their published capacities run from 2195 W to 2795 W with no monotonic order against the load field. The load field identifies a row; it does not predict its output.

How to verify a unit before purchase

Ask the supplier for a rating sheet that names the full model string, including the load field and the build field, and ask which test condition the capacity figure is quoted against. A sheet that names a shorter string cannot be matched to a catalogue row, and a capacity figure without a stated condition cannot be compared with the figures in this article. Ask which edition of the manufacturer manual the figures come from, because two rows of this class carry different columns in two editions of the same manual. Ask for the applicable safety certificate for the compressor itself, and treat a certificate for the assembled unit as a different document.

Sources