UV-C POWER CONVERSION CALCULATOR

This tool helps HVAC engineers convert UV-C lamp power into irradiance, energy, and dose values for coil irradiation applications. Enter per-lamp watts, number of lamps, coil area (ft² or inches), or irradiance, and the calculator will fill in the rest. Results include UV dose (J/ft², mJ/ft², µJ/ft²), lamp power density (W/ft², J/ft², µW/ft²), and ASHRAE conformance.

Assumes uniform distribution across the coil face; irradiance & dose use UV output factor k = 0.159.

Lamp Power

Coil Area & Irradiance

Exposure Time & Energy

UV Dose (avg over coil face)

Lamp Power Density

ASHRAE Conformance

Typical ASHRAE coil irradiation design guidance targets an electrical lamp power density of ≥ 6 W/ft² across the coil face to maintain clean coils and suppress microbial growth.

Awaiting calculation…

Conformance is evaluated on the electrical W/ft² basis. Legend: Green = Within (≥ 6 W/ft²). Red = Below 6 W/ft².

Assumptions: values are averaged over coil face (ft² basis). Irradiance & dose estimated with UV output factor k = 0.159 (UV_W = Lamp_W × 0.159). Actual values vary with lamp type/ballast, temperature, aging, quartz soiling, reflectance, view factors, and placement.

UV-C LAMP WATTAGES BY LAMP LENGTH

This chart provides a quick reference to UV-C lamp electrical wattage output based on lamp length across the UV Resources product families (RLM[X], DE[X], SL[X], SLN[X], DLN[X], and X PLUS). Each section highlights the nominal lamp length (in inches) paired with its corresponding lamp wattage (W). This data helps engineers, contractors, and facility managers:

  • Match lamp lengths to wattage requirements when designing or retrofitting UV-C systems.
  • Compare performance across product families.
  • Simplify specification and ordering by showing standardized lamp options.
PRODUCTLAMPS
RLMXLENGTH33364261
WATTS758098145
(2) TOTALP150160196290
(4) TOTALP300320392580
(6) TOTALP450480588870
DE[X]LENGTH243642
WATTS406992
SL[X]LENGTH16202430364261
WATTS384758718598145
SLN[X]LENGTH162202430364261
WATTS384758718598145
DLN[X]LENGTH1216202430
PER LMAPWATTS2838475871
SYSTEMWATTS567694116142
X PLUSLENGTH172333364560
WATTS112641466173

ASHRAE GUIDELINE REFERENCE

According to ASHRAE Handbook — HVAC Applications – Chapter on Ultraviolet Lamp Systems, typical coil irradiation designs aim for 6–12 W/ft² of coil face area to maintain a clean coil surface and suppress microbial growth.

For further details, see the official ASHRAE resource:
ASHRAE UV-C Disinfection Guidelines