Heating Load Volume
Calculator
Results
- Heating load (W)
- 2,340
- Heating load (kW)
- 2.34
- Power (BTU/h)
- 7,984.41228
- Temperature difference (K)
- 26
HVAC and plumbing results
| Heating load (W) | 2,340 |
| Heating load (kW) | 2.34 |
| Power (BTU/h) | 7,984.41228 |
| Temperature difference (K) | 26 |
formula-map diagram
- Heating load (W)
- 2,340
- Heating load (kW)
- 2.34
- Power (BTU/h)
- 7,984.41228
- Temperature difference (K)
- 26
HVAC and plumbing relationship
Formula
Q = V × f × (Tin − Tout)= 2340
Note
This is a simplified model: it applies a standard engineering formula to the numbers you entered. Conversions between BTU/h and kW use the exact factor 1 kW = 3412.142 BTU/h, but every sizing figure is an estimate. Air conditioner sizing uses the common 20 BTU/h per square foot rule of thumb, not a room-by-room load calculation, and it ignores insulation, glazing, orientation, ceiling height, infiltration and local climate. Heating loads use a single volumetric heat-loss factor in W/m³·K rather than a fabric-by-fabric U-value calculation. Air properties are fixed at 1.2 kg/m³ and water at 1000 kg/m³ and 4186 J/kg·K, with no correction for temperature, altitude or glycol. Duct and pipe results use the ideal continuity equation and ignore fittings, bends, roughness and system effect unless you enter those losses yourself. The Hazen-Williams equation is valid only for water in full turbulent flow at ordinary temperatures. Water hammer uses the Joukowsky surge, an upper bound for instant closure. Tank drainage assumes a prismatic tank and steady free discharge. Hot water recovery and condensate figures ignore standing losses and coil bypass. Size real systems with a proper heat-loss survey and have the work checked by a qualified HVAC or plumbing professional.
More in HVAC and plumbing
See all →Frequently asked questions
Why does this calculator use room volume instead of floor area?+
Heat loss depends on the total air volume being warmed and the surfaces losing heat, not just the floor footprint. A room with a 4-meter ceiling holds much more air — and loses more heat through walls — than an identical-footprint room with a 2.4-meter ceiling.
What does the watts-per-cubic-meter factor represent?+
It's a simplified heat-loss coefficient that bundles together insulation quality, climate severity, and typical air infiltration for a building type. Older, poorly insulated buildings use a higher factor; new, well-insulated construction uses a lower one.
Does this account for window and door heat loss separately?+
No, this volume-based method is a simplified estimate that folds average glazing and door losses into the single heat-loss factor. A room with unusually large windows or poor door seals will lose more heat than the estimate suggests.
How accurate is a volume-based estimate compared to a full heat loss survey?+
It's a reasonable ballpark for sizing a single room's radiator or heater, typically within 15-20% of a detailed room-by-room calculation, but a full survey accounts for specific wall construction, window types, and orientation for a more precise result.
Should I add a safety margin to the calculated heating load?+
Many installers add 10-15% on top of the calculated figure to cover colder-than-average days and account for heat-up time, especially in rooms that are only heated intermittently rather than kept at a constant temperature.