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AC Efficiency & Inverter Savings Calculator

Payback period

6 yr 9 mo

Your payback period comes out to about 6 yr 9 mo.

Recover $300.00 purchase premium via $3.72/mo electricity savings

On/Off (fixed speed)

Compressor cycles full power then off — temperature swings, higher peak draw.

~317 W avg

Inverter (variable speed)

Modulates compressor RPM — steadier room temp, quieter runs, less wear.

~206 W avg

Cooling capacity

13,500BTU/h

≈ 1.5 HP

Monthly kWh saved

26.6kWh

35% vs on/off

Annual savings

$44.64/yr

Summer-month estimate × 12

Why inverter AC costs less to run

  • Stable temperature — variable speed avoids overshoot and re-starts that waste kWh.
  • Quieter operation — lower average RPM means less noise than full-blast on/off cycles.
  • Less compressor wear — soft starts and partial load reduce mechanical stress over years.
Check your home insulation efficiency too

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How this calculator works

How to use the AC Efficiency & Inverter Savings Calculator

The Formula

Fixed-speed compressors run at full power then stop; inverter drives modulate RPM to match load. Field studies often show 30–40% lower kWh for comparable comfort.

Practical Example

Average watts ≈ (BTU/h ÷ EER ÷ 3.412) × duty cycle. Monthly kWh = watts × hours/day × 30 ÷ 1,000. Inverter kWh = on/off kWh × (1 − savings %). Cost = kWh × $/kWh.

About AC Efficiency & Inverter Savings Calculator

On/off vs. inverter

Fixed-speed compressors run at full power then stop; inverter drives modulate RPM to match load. Field studies often show 30–40% lower kWh for comparable comfort.

Monthly cost formula

Average watts ≈ (BTU/h ÷ EER ÷ 3.412) × duty cycle. Monthly kWh = watts × hours/day × 30 ÷ 1,000. Inverter kWh = on/off kWh × (1 − savings %). Cost = kWh × $/kWh.

Frequently asked questions

Q: HP or BTU? A: 1 HP ≈ 9,000 BTU/h for room AC. Q: Payback? A: (Inverter price − on/off price) ÷ monthly savings. Q: Pair with envelope work? A: Better insulation lowers load for any AC type—see Home Insulation Savings.

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