There is a number hiding on your electricity bill that costs you money every month. There is probably a second one in the boiler room, and a third in the genset shed. Most businesses never see them, because finding them takes an engineer with a calculator — and engineers with calculators usually arrive attached to a sales pitch.
So we separated the two. The Karnot Engineering Hub now holds 30 free calculators — the same methods our own engineers use, with every constant cited to its standard: the Philippine Electrical Code, the Philippine Distribution Code, IEEE, ISO, IEC, CIBSE, ASHRAE. Use them with no login, no email, no callback. If you never buy anything from us, the tools still work and you're still welcome.
Here's a tour of the ones most likely to find you money, with the worked examples you can reproduce yourself.
1. The penalty hiding on your bill
The Philippine Distribution Code requires your power factor to stay at or above 85%. Most motor-heavy plants sit below it without knowing. The common billing scheme then multiplies your billed demand by 0.85 ÷ your actual power factor — so a plant recording 100 kW at 0.78 power factor is billed as if it drew 109 kW. At a ₱350/kW demand charge, that's about ₱3,100 a month for power you never used — roughly ₱37,700 a year, every year, until corrected.
The Power Factor Correction calculator reads the two numbers off your bill, sizes the capacitor bank (a 50 kVAr bank fixes the example above), and shows the monthly saving. The honest part: it also tells you capacitors won't cut your kWh — anyone promising that is selling something else.
2. Hot water, sized the way you actually count it
Nobody knows their hot water demand in kilowatts. You know rooms, beds, or covers. The Hot Water Demand calculator works in your units: a 50-room resort at 90 litres per room needs about 4,500 litres of 60°C water a day — roughly 173 kWh of heat. It sizes the heater, the storage tank, and tells you which machine fits: an AquaHERO for a villa or B&B, an iHEAT for a hotel. The demand figures come from CIBSE Guide G, and they're editable if you know your real numbers.
3. What your boiler would cost as a heat pump
The Boiler to Heat Pump converter takes your boiler in whatever units the nameplate uses — kW, boiler horsepower, or steam kg/h — and converts it honestly. The example we verify it against: a 100 kW diesel boiler running 4,000 hours a year at 60% load burns about ₱2.4 million of fuel. The same heat from a heat pump cascade costs about ₱0.9 million of electricity — a 63% cut.
The honest limit, stated up front: heat pumps deliver up to 75°C. They do not make live steam, and the tool says so rather than hiding it. If you run a steam boiler, it shows what the heat pump can take (everything below 75°C, plus feedwater pre-heat) and leaves the steam where it belongs.
4. The genset that's two sizes too big
Here's a result that surprises people. A 40 kW plant whose biggest motor is a 30 kW compressor started direct-on-line needs about a 100 kVA generator — double what the running load suggests — because that one motor demands six times its running current for the first moments. Put a VFD on the compressor and 75 kVA does the job. The Genset Sizing calculator works both constraints (ISO 8528 loading and motor starting) and takes the worse case; the Motor Starting calculator shows all four starting methods side by side.
It also prices the fuel honestly: a diesel genset makes power at roughly ₱24/kWh — about double the grid. Gensets are for outages, not baseload, and the tool says so.
5. Four ways to heat the same water
Heating 1,000 litres from 27°C to 60°C takes 38.4 kWh of heat. What that costs depends entirely on the machine:
| Method | Cost per 1,000 L |
|---|---|
| Electric heater | about ₱461 |
| LPG boiler | about ₱393 |
| Diesel boiler | about ₱384 |
| Karnot heat pump | about ₱115 |
Notice the honest part: the three fuels land close together — at today's cylinder prices LPG only just undercuts electric, and diesel edges LPG. The Water Heating Cost comparison shows it exactly as it prices up, no thumb on the scale. The heat pump beats the cheapest of them more than three times over, and every price in the tool is editable to your own invoices.
6. "What HP aircon do I need?"
The most-asked cooling question in the country, answered without the guesswork: a 20 m² bedroom with average sun, two people and a TV needs about 4.8 kW — a 2.0 HP unit, costing roughly ₱2,600 a month on an inverter at 8 hours a night. The Comfort Cooling estimator also pushes back on the national habit of buying "one size bigger to be safe": an oversized aircon cools fast, dehumidifies badly, and cycles itself to an early grave.
7. Solar and batteries, sized to what you use
A site using 20 kWh a day needs about a 4.5 kWp array under Philippine sun — and if 40% of that use is after dark, about 10 kWh of battery keeps the evening running on stored sunshine. The Solar & Battery Autonomy calculator explains the one rule that matters here: exports are credited at roughly half what you pay for imports, so a system sized to your own use beats one sized to your roof. It will also tell you honestly when a battery isn't worth it — day-heavy businesses often do better with panels alone.
And twenty-three more
For the electrically minded: voltage drop to the Philippine Electrical Code's 3%/5% limits (it also prices the heat your undersized cable wastes — about ₱7,200 a year in the worked example), kW/kVA/amps with running cost, cable sizing, electrical load and breaker sizing. For the thermally minded: heat exchanger LMTD, thermal storage sizing, pinch analysis, psychrometrics, steam tables, refrigerant properties, and the rest — the full list is here.
Why give this away?
Because the numbers are the argument. We build heat pumps that turn ₱1 of electricity into about ₱4 of heat. If that claim only survived inside a salesman's spreadsheet, it wouldn't be worth your money. It survives in the open, with the constants cited, where anyone can check it — and a customer who has already run their own numbers is a better customer to sit down with.
The tools also say no on our behalf. Light hot-water users, day-heavy sites that don't need batteries, rooms that need a smaller aircon than the shop recommends — the calculators will tell you, because a tool that only ever says "buy" isn't a tool, it's an advert.
Who's telling you this
Karnot Energy Solutions Inc. is a Philippine company in Mapandan, Pangasinan. We design and build natural-refrigerant heat pumps — AquaHERO for homes, iHEAT for businesses, iCOOL for cold chains — engineered for this climate, and serving the Philippines, the UK, the US and Canada. The calculators digitise thirty-plus years of thermal engineering practice; we use the same methods to design every system we quote.