Baseboard Length for a Room Load
The active fin-tube length a room's heat load needs.
Example
You enter
- Target room load (BTU/hr) 4800
- Avg water temp (°F) 180
- Flow (gpm) 1
- Model slant_fin_baseline
You get
- Active baseboard length 8.3 ft
Checked against published worked examples from: Slant/Fin Corporation.
Details, formula, and sources
Scopelength = load / (output per ft x flow factor), with output per ft interpolated from the manufacturer table at the average water temperature. A 4,800 BTU/hr room on 180 F water needs 8 ft; raise the supply to 200 F and it drops to 7 ft (hotter water shortens the run). Answers 'how many feet of baseboard' instead of the output of one length. Active length only; add the inactive ends. The manufacturer rating and the room heat loss govern.
Formula or tablelength_ft = target_load / (btu_per_ft(water_temp) x flow_factor); the inverse of btu_total = btu_per_ft x length x flow_factor. btu_per_ft from manufacturer tables interpolated by water temperature.
Source and editionSlant/Fin Fine Line 30 typical-curve and high-output reference (manufacturer-attributed).
Free accessFree at slantfin.com.
What governsEstimate. AHJ and licensed mechanical contractor govern. ACCA Manual J / D / S supersede rules of thumb.
API field namestarget_btuhr, water_temp_F, flow_gpm, model, length_ft
- Curve table data/hvac/baseboard-output.json keyed to model and water temperatureSlant/Fin technical literature
- Active length returns the active fin-tube length; add inactive ends, and the water cools along a long runhydronic practice