UV quartz sleeve--output or Wavelength distribution

[wooden_reefer]

A UV unit that has Quartz sleeve is certainly better for maintenance. Change of bulb is so much easier.

But is it true that UV is more effective with a quartz sleeve? IME, it is .

I think it is because when there is a quartz sleeve, the bulb will run warmer, as less heat is transfered into the water.

A warmer bulb generate more power or it have a lower wavelength distribution.

Any electrical guru here how about florescence lighting very well can share knowledge on the effect of temp on the output and/or wavelength distribution of the bulb?

[wooden_reefer]

I just studied the WL profile of some UVC bulbs.

It turns out that there is not much of a distribution to speak of. It is rather sharp on the UV side with some minor scattering. Does it change with temp nonetheless.

No temp on the graphs is shown.

[syrinx]

UV is shielded by regular glass- quartz glass allows much more UV through the envelope thus a lower wattage bulb is as effective as a higher wattage in a normal glass tube.

[wooden_reefer]

Originally Posted by syrinx

UV is shielded by regular glass- quartz glass allows much more UV through the envelope thus a lower wattage bulb is as effective as a higher wattage in a normal glass tube.

But units without QS have nothing more.

For units w/o GS, it is the glass of the bulb and then water. How can you have more transmission for having something in-between?

[syrinx]

Never seen one with no sleeve whatsoever- doesnt seem electrically sound.

[wooden_reefer]

Originally Posted by syrinx

Never seen one with no sleeve whatsoever- doesnt seem electrically sound.

Sound if built correctly, IMO.

A rubber compression fitting nut hugs the glass of the bulb. The water should not contact the metal end of the bulb, just the glass.

The water pressure directly on the bulb is not a concern, since in the proper use of UV flowrate and pressure is low.

When you flush it with tap water while cleaning it , you have to be careful to use slow flow as well.

My concern is not safety, it is effectiveness.

Bulb with direct water contact without GS will run cooler, may be much cooler. Does lower temp affect light output and/or wavelength?

[billsreef]

Originally Posted by syrinx

Never seen one with no sleeve whatsoever- doesnt seem electrically sound.

They do exist, I don't like them for several reasons. The seals are prone to leakage, harder to keep bulb clean, and as wooden_reefer notes they run cooler and therefore less efficient.

wooden_reefer,

You are quite correct about the quartz sleeve allowing the UV bulb to run warmer. This lets its run at peak efficiency and put out more power than if running cool. Again, fairly standard fluorescence technology. The other pluses to the quartz sleeve is the ability to change the bulb with the water still running, easy to clean the sleeve (especially if you get one with the built in wiper) and better isolation of the water and electric.