Question 1

Where do calculator results and assumptions come from?

Accepted Answer

Each calculation keeps its working visible so you can review the inputs, method, and assumptions in context. Read the homepage methodology section or browse the full calculator directory.

Question 2

Which inputs does a cooling-load estimate use?

Accepted Answer

It uses IT electrical load in kW, lighting load in W, a whole-number people count, and an envelope heat-gain estimate you supply in BTU/hr. The illustrative people assumption is 450 BTU/hr per person (250 sensible + 200 latent) for moderately active office work at 75°F. This is an assumption, not measured facility data; envelope gain is not derived from building details. Read the cooling-load calculator guide or open the cooling-load calculator.

Question 3

How is cooling load calculated?

Accepted Answer

Total BTU/hr = ((IT kW × 1,000) + lighting W) ÷ 0.2930711 + (people × 450) + envelope BTU/hr. Refrigeration tons = total BTU/hr ÷ 12,000; thermal cooling kW = total BTU/hr × 0.0002930711. This is a first-pass arithmetic sum. It does not model design weather, envelope construction, solar gain separately, ventilation, diversity, or cooling-system effects. See the cooling-load calculator guide or use the calculator.

Question 4

How are PUE and DCiE calculated?

Accepted Answer

PUE = total facility power ÷ IT load. DCiE (%) = IT load ÷ total facility power × 100. The optional annual energy estimate assumes constant facility power for 8,760 hours, with no leap-year adjustment. A calculation from entered power is not an energy-metered or audited annual PUE. Review the PUE and DCiE calculator guide or open the calculator.

Question 5

How does the UPS runtime estimate work?

Accepted Answer

Nominal bank energy = V × Ah × series batteries × parallel strings. Runtime applies the efficiency and remaining-capacity percentages as fractions, then divides by load in watts. The arithmetic assumes a fully charged battery, constant load, and an idealized energy calculation. It is not model-specific or guaranteed; check the manufacturer’s data for the actual system. Read the UPS runtime calculator guide or open the calculator.

Question 6

What does the cooling-airflow result include?

Accepted Answer

The estimate uses CFM = sensible heat load ÷ (1.08 × temperature rise). The 1.08 coefficient is a simplified dry-air assumption. The calculator does not calculate latent load or correct for air-state or elevation conditions. Open the cooling-airflow calculator.

Question 7

How does rack-power sizing account for phase and power factor?

Accepted Answer

For single phase, real-power capacity = voltage × current × power factor. For balanced three phase, real-power capacity = √3 × line-to-line voltage × line current × power factor. The calculator applies its planning cap separately to nominal capacity; that cap is an explicit planning assumption, not an equipment rating. Open the rack-power calculator.

Question 8

Can these results be used as final designs or equipment ratings?

Accepted Answer

No. These are planning estimates, not final designs, verified facility measurements, or equipment ratings. The homepage explains that results do not replace a licensed engineer’s design or manufacturer data. Review the homepage methodology section, browse the calculator directory, and read the cooling-load guide, PUE and DCiE guide, and UPS runtime guide for calculator-specific limits.