Room-size starting point
18,000 BTU is closest to ENERGY STAR’s 700–1000 sq. ft. room-size row.
ENERGY STAR sizing chart ↗
18,000 BTU heat pumpModel #: 4PAMSHQCO18 / 4PAMSHQCW18
Check model number 4PAMSHQCO18 / 4PAMSHQCW18 at your preferred retailer.
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What the published numbers mean before you compare every spec.
18,000 BTU is closest to ENERGY STAR’s 700–1000 sq. ft. room-size row.
ENERGY STAR sizing chart ↗At 5°F, certified output is 18,000 BTU/h — 100% of its 47°F rating.
ENERGY STAR ↗The cited fields do not confirm a pre-charged line set or DIY-line designation for this model.
Voltage is not published in the sources we cite, so confirm it before choosing equipment.
HSPF2 10 is below the 10.2 average among 125 models in the same rounded capacity class.
ENERGY STAR ↗Your room is near 700–1000 sq. ft. under the ENERGY STAR starting-point assumptions, and a load calculation agrees.
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.
| Outdoor model number | 4PAMSHQCO18 |
|---|---|
| Indoor model number | 4PAMSHQCW18 |
| AHRI reference number | 216498646 |
| Series | HiULTRA |
| Heating capacity at 47F | 18,000 BTU/h |
| Heating capacity at 17F | 18,000 BTU/h |
| Heating capacity at 5F | 18,000 BTU/h |
| SEER2 | 21 |
| EER2 | 13 |
| HSPF2 | 10 |
Values marked ENERGY STAR come from the certification dataset; values marked Manufacturer spec come from the linked product documents.
The sources we cite do not publish these values for this model, so we leave them blank rather than guess.
Room-size guidance is a starting point, not a load calculation. Confirm sizing and installation requirements with a qualified contractor.
Check your room size