What HVAC really costs a NYC building per year.

The derivation, shown in full

A cooling system's annual energy cost is four numbers multiplied together:

tons × kW per ton × equivalent full-load hours × $ per kWh

Our inputs, and why:

• ~1.0 kW per ton. The draw of the older, installed equipment actually running on NYC roofs, not the nameplate of a new high-SEER unit. Monitoring targets the existing fleet, so we model the existing fleet.
• ~1,600 equivalent full-load hours. A commercial cooling season in NYC compressed into full-load terms. Spaces with high internal gains (kitchens, offices, retail, south exposure) run 1,500 to 2,000 equivalent hours; we sit near the low end.
• $0.18 per kWh.A deliberately conservative marginal energy rate. This is the honesty flag that matters most: NYC's all-in commercial rate realistically runs $0.24 to $0.30 per kWh (EIA put the NY commercial average at 21.9 to 23.5 cents in 2026), so every figure on this page is a floor. On an all-in rate, multiply everything below by 1.33 to 1.67.

Multiply it out: 1 ton × ~1.0 kW/ton × ~1,600 hours × $0.18 comes to about $286 per ton per year. A 5-ton unit is about $1,432 a year. A 50-ton building, ten 5-ton units, is about $14,317 a year, leaving every month whether anyone thinks about it or not.

Scaled, with the waste rows

A cooling season is not the whole year

The table above is the cooling floor. Commercial NYC equipment is increasingly a heat pump running year-round, and that is how we model it: heating adds about 2,300 equivalent full-load hours at a seasonal COP around 2.3, roughly $3,165 per 5-ton unit at the same $0.18/kWh basis. The full HVAC line is about $4,600 per 5-ton unit per year, about $46,000 on the 50-ton building, and a 15% recovery scenario on that line is worth about $690 and $6,900 a year respectively.

On a demand-billed SC9 meter, the demand charge adds roughly $3,900 per 5-ton unit a year (at $65.79 per kW-month), bringing the all-in line to about $8,500 per unit, about $85,000 on the 50-ton building. The demand-charge explainer walks through why degraded equipment pays that line twice.

The 15-year rows are flat, with no rate escalation. Con Ed's approved rate path adds 3.5%, 3.2%, and 3.1% per year through 2028; carrying a ~3.2% annual escalation through the 15 years lifts the cumulative figures by roughly a quarter. And again: on an all-in commercial rate, every row multiplies by 1.33 to 1.67.

Where the waste rows come from

The 15% and 30% rows are not a guess. They are the documented energy penalties of the faults deferred maintenance leaves in place, each cited on the equipment's own energy: a clogged filter costs 5 to 15%of an air conditioner's energy (U.S. DOE), an improper refrigerant charge costs 10 to 20%of unit efficiency (Downey & Proctor 2002, a 13,000-unit ACEEE field study), and field retrofits of rooftop-unit controls recovered 5 to 15%of building HVAC energy (PNNL-22656). A neglected unit stacks several of these at once, so ~15% is a conservative floor and 30% is the multi-fault case. The widely-quoted 15 to 30% figure from Katipamula & Brambley (2005) points the same direction, but it measures whole-building commercial energy, not the HVAC line, so we don't use it in these rows. The full sourcing discipline is in How we make claims.

HVAC against the whole electric bill

For scale: in U.S. commercial buildings, cooling is about 14% of electricity use and ventilation about 18% (EIA, CBECS 2018). So cooling plus ventilation is roughly 32%of a commercial building's electricity, call it a third of the electric bill, before any electric heating. HVAC is usually the largest single line an owner can move without touching the rest of the building. That share is context, not a savings claim; the waste and recovery numbers above are always scoped to the HVAC line itself.

What the model leaves out

This is a cooling-energy floor, and three real cost lines sit on top of it. On a demand-billed commercial meter, peak-kilowatt charges can dominate; on one real NYC commercial bill we analyzed, demand was about 70% of the total (see Demand charges, explained). Heating on an all-electric heat pump is a larger load than cooling in NYC's climate. And for buildings over 25,000 square feet, wasted kilowatt-hours carry LL97 carbon-penalty exposure at $268 per metric ton CO2e over cap. Each of those raises the stakes above the floor shown here.

If you own or operate a building, the buildings page applies this math to your situation, and pricing shows the rule we hold ourselves to: the subscription is priced below the energy it is expected to save. Actual savings depend on your equipment, runtime, and utility rate.

Sources

• U.S. Energy Information Administration, CBECS 2018, commercial electricity end uses (cooling ~14%, ventilation ~18%): eia.gov/tools/faqs/faq.php?id=1174
• U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A (NY commercial average rate): eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_a
• U.S. Department of Energy, Air Conditioner Maintenance (clogged filter: 5 to 15% of an AC's energy use): energy.gov/energysaver/air-conditioner-maintenance
• Downey, T. & Proctor, J. (2002), “What Can 13,000 Air Conditioners Tell Us?”, ACEEE Summer Study: aceee.org/files/proceedings/2002/data/papers/SS02_Panel1_Paper05.pdf
• Pacific Northwest National Laboratory, PNNL-22656 (rooftop-unit control retrofits: 5 to 15% of building HVAC energy).
• Katipamula, S. & Brambley, M.R. (2005), HVAC&R Research 11(1), whole-building commercial figure: osti.gov/biblio/15011268
• Con Edison electric rate schedules: coned.com/en/rates-tariffs/rates/electric-rates-schedule