Recommendation required

If you wanted to disinfect a 2’x2’ square surface, how many of which UVC LEDs would be required, and at what range of distances would they be effective?

To maximize range, likely we would want the most powerful option, but interested in your recommendation.

Effectiveness of UV radiation for germicidal applications varies with quite a few application factors including susceptibility of the target pathogen, incident intensity, wavelength, duration, filtering effects of system elements or surrounding media, surface geometry, etc.

Generally speaking, UV-C sources with peaks in the 240~300nm range seem to be quoted as most effective. LED products of that sort that we’ve got listed can be found here. Note that development of LEDs as UV-C sources has not kept pace with those used for general lighting, and for this reason other lamp types are still predominantly used for germicidal applications

Our application is covid19 related, and we are looking to disinfect a surface.

So the question is what bulbs if any can be used at a distance of 1 foot, and at that distance what area would one bulb disinfect? It would be in a closed sealed container, if outside light etc…
has any impact there will not be any.

UV-C lamps in form factors similar to common fluorescents are available from lighting specialty suppliers, and would probably be a better choice for such an application since they offer significantly more UV radiation per dollar than current UV LEDs.

Short of taking things to ridiculous extremes, I’ve no hard & fast answer to the “which bulb at (x) distance” question. In general, the more incident UV energy per area of treated surface, the more potent the effect. There will be some sort of exposure time vs. intensity curve needed to achieve a given level of reduction in viable cells, and it will change somewhat depending on the UV wavelength used. What those numbers are, I don’t know.

Beyond that, things such as the porosity of the treated surface can also have an effect; the UV photon bullets have to hit the viral cells to do damage, so if the surface in question provides lots of foxholes in which they can hide during bombardment, the treatment will be less effective.

I suspected that would be the answer. LED would be so convenient to use, but I had feeling the range and power would be too low for our application.

Do you have one or two manufacturers you would recommend we contact for this?

I am assuming you don’t carry this product yourselves.

Philips lighting might be one worth checking, though I’d have confidence in most any of the major US/European/Japanese suppliers that provide meaningful product datasheets–in this case, that means listing a UV radiant output at a minimum.

You are correct in that DK does not carry UV-C fluorescent lamps of this type at present, though there are numerous lighting specialty outfits online that do. As with any product related to sanitation matters however, availability may be limited at this point in time.