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Air Filter Energy Calculator

Compare the total operating cost — filters, energy, labor, and carbon — of up to three filter systems. System #1 is your current (baseline) setup; savings for Systems #2 and #3 are shown against it. This opens with a sample project you can explore — edit any gold field, or clear it and enter your own.

⚠️ Research & Development Sandbox — a tool we're still refining. Notes here are for on-screen use and printing; they are not saved to an account.

Customer NameCustomer AddressPrepared ByDate

You can edit these fields Calculated automatically

Field	System #1 (baseline)	System #2	System #3	Notes
Filter Information
Filter Type
Filter Manufacturer
Filter Description
Filter Model Number
Filter Efficiency
Size (W x H x D)
Filter Price ($ per filter)
Initial Resistance (In. W.G.)
Recommended Final Resistance (In. W.G.)
System Information
AHU Identification
System Airflow Rate (CFM)
Number of Filters in Bank
Estimated Filter Life (months)
Days in Operation (per year)
Hours in Operation Per Day
Motor / Blower Efficiency (decimal, 0.6 = 60%)
Energy & Labor Cost
Energy Cost ($/kWh)
Labor Cost ($/hour)
Calculated — Airflow & Energy (per filter)
Initial Resistance (Pa)	—	—	—	= Initial (In. W.G.) × 249.09
Final Resistance (Pa)	—	—	—	= Final (In. W.G.) × 249.09
Average Resistance (Pa)	—	—	—	= (Initial Pa + Final Pa) ÷ 2
System Airflow (m³/sec)	—	—	—	= CFM ÷ 2120
Filter Airflow (m³/sec)	—	—	—	= System Airflow ÷ # Filters
Operating Hours (per filter life)	—	—	—	= Days × Hours ÷ (12 ÷ Life)
Energy Consumption (kWh per filter)	—	—	—	= Filter Airflow × Avg Pa × Hours ÷ Efficiency ÷ 1000
Calculated — Annual Operating Cost
Energy Cost per Filter ($)	—	—	—	= kWh × $/kWh
Energy Cost per Changeout ($)	—	—	—	= per filter × # Filters
Annual Filter Cost ($)	—	—	—	= # Filters × Price × (12 ÷ Life)
Annual Energy Cost ($)	—	—	—	= per changeout × (12 ÷ Life)
Labor Time per Changeout (hrs)	—	—	—	= 5 min × # Filters ÷ 60
Annual Labor Cost ($)	—	—	—	= Labor Time × Rate × (12 ÷ Life)
Total Operating Cost ($ / year)	—	—	—	= Filter + Energy + Labor
Calculated — Carbon (CO₂)
CO₂ per Filter (lb)	—	—	—	= kWh × 1.35
Annual CO₂ (lb)	—	—	—	= per filter × # Filters × (12 ÷ Life)

Operational Savings ($) vs System #1Positive = cheaper than the baseline system

	Monthly	Yearly	3-Year	% vs #1
System #2	—	—	—	—
System #3	—	—	—	—

Monthly = annual ÷ 12 · 3-Year = annual × 3

Carbon (CO₂) Savings vs System #1Positive = less CO₂ than the baseline system

	Monthly	Yearly	3-Year
System #2	—	—	—
System #3	—	—	—

Reported in pounds (lb) of CO₂. Monthly = annual ÷ 12 · 3-Year = annual × 3

General Notes

How the numbers are calculated

Every calculated field below uses the same formulas as the original Airguard energy spreadsheet. Variable names match the input field labels above.

Airflow & energy (per filter)

Initial Resistance (Pa): = Initial Resistance (In. W.G.) × 249.09
Final Resistance (Pa): = Recommended Final Resistance (In. W.G.) × 249.09
Average Resistance (Pa): = (Initial Resistance Pa + Final Resistance Pa) ÷ 2
System Airflow (m³/sec): = System Airflow Rate (CFM) ÷ 2120
Filter Airflow (m³/sec): = System Airflow (m³/sec) ÷ Number of Filters in Bank
Operating Hours (per filter life): = Days in Operation × Hours per Day ÷ (12 ÷ Filter Life months)
Energy Consumption (kWh per filter): = Filter Airflow × Average Resistance (Pa) × Operating Hours ÷ Motor Efficiency ÷ 1000

Annual operating cost

Energy Cost per Filter ($): = Energy Consumption (kWh) × Energy Cost ($/kWh)
Energy Cost per Changeout ($): = Energy Cost per Filter × Number of Filters in Bank
Annual Filter Cost ($): = Number of Filters × Filter Price × (12 ÷ Filter Life months)
Annual Energy Cost ($): = Energy Cost per Changeout × (12 ÷ Filter Life months)
Labor Time per Changeout (hrs): = 5 minutes × Number of Filters ÷ 60
Annual Labor Cost ($): = Labor Time per Changeout × Labor Cost ($/hour) × (12 ÷ Filter Life months)
Total Operating Cost ($ / year): = Annual Filter Cost + Annual Energy Cost + Annual Labor Cost

Carbon (CO₂)

CO₂ per Filter (lb): = Energy Consumption (kWh) × 1.35
Annual CO₂ (lb): = CO₂ per Filter × Number of Filters × (12 ÷ Filter Life months)

Savings (Systems #2 & #3 vs the System #1 baseline)

Annual Dollar Savings: = Total Operating Cost of System #1 − Total Operating Cost of that system
Monthly Dollar Savings: = Annual Dollar Savings ÷ 12
3-Year Dollar Savings: = Annual Dollar Savings × 3
% vs #1: = Annual Dollar Savings ÷ Total Operating Cost of System #1
Annual Carbon Savings (lb): = Annual CO₂ of System #1 − Annual CO₂ of that system
Monthly / 3-Year Carbon Savings: = Annual Carbon Savings ÷ 12 / × 3

Constants used

249.09 — Pascals (Pa) per inch of water gauge (In. W.G.). Converts resistance to metric pressure.
2120 — CFM per m³/sec. Converts system airflow to metric.
1.35 — pounds of CO₂ produced per kWh (fossil-fuel power plant emission factor).
5 minutes — assumed labor time to change one filter.
÷ 1000 — converts watts to kilowatts (kWh).

Note on annualizing: energy, labor, and CO₂ are all scaled by 12 ÷ Filter Life (the number of changeouts per year), so systems with different filter lifespans compare correctly. When Filter Life = 12 months this factor is 1.