Overall For the same water‑treatment capacity, the operating cost of medium‑pressure UV sterilizers is significantly higher than that of low‑pressure UV sterilizers.
Low‑pressure UV Electro‑optical conversion efficiency reaches 35‑40 precent. Most electric power is converted into effective 254 nm UV light with low heat generation. The total power consumption is low, leading to lower electricity expense.
Medium‑pressure UV Electro‑optical conversion efficiency is only 10‑20 precent. Most electrical energy is converted into heat. Single‑lamp power ranges from several hundred watts to several kilowatts, plus air‑cooling or water‑cooling systems for heat dissipation. Electricity cost per ton of treated water is much higher.
Low‑pressure UV lamps Service life 8000‑12000 hours. Low unit price and long replacement cycle, resulting in low consumable cost.
Medium‑pressure UV lamps Service life 3000‑6000 hours with more frequent replacement. Lamp unit price is far higher than low‑pressure lamps, which increases consumable expenditure.
Medium‑pressure units operate at high working temperature. Ballasts and cooling components have relatively higher failure rates, so spare‑part repair cost is higher.
Low‑pressure UV equipment features simple structure and low failure rate. Routine work mainly consists of quartz sleeve cleaning.Selection Reminder
Although medium‑pressure UV has higher operating cost, it provides oxidation functions such as chloramine and TOC degradation as well as combined chlorine breakdown typical for public swimming pools, which cannot be achieved by low‑pressure UV. If photo‑oxidation degradation is required for the project, higher operating cost has to be accepted and shall not be the only selection criterion.
For disinfection only and low operating‑cost priority: choose low‑pressure UV.
For disinfection plus photo‑oxidation degradation e.g. chloramine removal for swimming pools : choose medium‑pressure UV, with acceptance of higher electricity and consumable costs.