

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.
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.
PRODUCT | LAMPS | |||||||
---|---|---|---|---|---|---|---|---|
RLMX | LENGTH | 33 | 36 | 42 | 61 | |||
WATTS | 75 | 80 | 98 | 145 | ||||
(2) TOTAL | P | 150 | 160 | 196 | 290 | |||
(4) TOTAL | P | 300 | 320 | 392 | 580 | |||
(6) TOTAL | P | 450 | 480 | 588 | 870 | |||
DE[X] | LENGTH | 24 | 36 | 42 | ||||
WATTS | 40 | 69 | 92 | |||||
SL[X] | LENGTH | 16 | 20 | 24 | 30 | 36 | 42 | 61 |
WATTS | 38 | 47 | 58 | 71 | 85 | 98 | 145 | |
SLN[X] | LENGTH | 16 | 220 | 24 | 30 | 36 | 42 | 61 |
WATTS | 38 | 47 | 58 | 71 | 85 | 98 | 145 | |
DLN[X] | LENGTH | 12 | 16 | 20 | 24 | 30 | ||
PER LMAP | WATTS | 28 | 38 | 47 | 58 | 71 | ||
SYSTEM | WATTS | 56 | 76 | 94 | 116 | 142 | ||
X PLUS | LENGTH | 17 | 23 | 33 | 36 | 45 | 60 | |
WATTS | 11 | 26 | 41 | 46 | 61 | 73 |
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