Room-size starting point
28,000 BTU is closest to ENERGY STAR’s 1500–2000 sq. ft. room-size row.
ENERGY STAR sizing chart ↗
28,000 BTU heat pumpACIQ 28,000 BTU Wall-MountES-27Z-M3B
AHRI reference 210857386
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Where to buy
Check model number ES-27Z-M3B at your preferred retailer.
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Decision guide
At a glance
What the published numbers mean before you compare every spec.
Cold-weather output
At 5°F, certified output is 19,000 BTU/h — 68% of its 47°F rating.
ENERGY STAR ↗DIY status not confirmed
The cited fields do not confirm a pre-charged line set or DIY-line designation for this model.
Electrical details missing
Voltage is not published in the sources we cite, so confirm it before choosing equipment.
Heating efficiency in its size class
HSPF2 9.5 is below the 9.8 average among 74 models in the same rounded capacity class.
ENERGY STAR ↗Good fit if…
Your room is near 1500–2000 sq. ft. under the ENERGY STAR starting-point assumptions, and a load calculation agrees.
Think twice if…
You have not confirmed the voltage, room load, and installation requirements for this exact model.
Room guidance is a screening estimate for standard conditions. Check your room inputs; use Manual J for final sizing.
Certified spec table
| Outdoor model number | ES-27Z-M3B |
|---|---|
| AHRI reference number | 210857386 |
| Series | ES |
| Heating capacity at 47F | 28,000 BTU/h |
| Heating capacity at 17F | 21,000 BTU/h |
| Heating capacity at 5F | 19,000 BTU/h |
| SEER2 | 24.6 |
| EER2 | 12.7 |
| HSPF2 | 9.5 |
Values marked ENERGY STAR come from the certification dataset; values marked Manufacturer spec come from the linked product documents.
Other certified configurations of this outdoor unit
ACIQ ES-27Z-M3B appears in the certification records under 4 separate certificate numbers. The equipment is the same; the tested pairing and the resulting ratings differ. This page carries them all.
| AHRI reference | Indoor unit | Heating at 47°F | Heating at 5°F | SEER2 | HSPF2 |
|---|---|---|---|---|---|
| 210857386 | Not supplied | 28,000 BTU/h | 19,000 BTU/h | 24.6 | 9.5 |
| 210857387 | Not supplied | 28,000 BTU/h | 18,700 BTU/h | 21 | 9.2 |
| 210857388 | Not supplied | 28,000 BTU/h | 18,800 BTU/h | 22.8 | 9.35 |
| 210857404 | Not supplied | 28,000 BTU/h | 19,000 BTU/h | 24.6 | 9.5 |
Every row comes from the same certification record set, retrieved 2026-08-09. Ask the seller which certificate number the unit you are quoted matches.
Specs not published for this model
The sources we cite do not publish these values for this model, so we leave them blank rather than guess.
Indoor model numberVoltageMinimum circuit ampacityMaximum breaker / fuseLine set length rangePre-charged line setBrand DIY line
Check the fit for your room
Room-size guidance is a starting point, not a load calculation. Confirm sizing and installation requirements with a qualified contractor.
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