Stainless Steel Heat Exchanger

A stainless steel heat exchanger transfers thermal energy from a heating source — boiler, solar, or combined system — to the mikveh pool water without mixing the two circuits. Hot water from the heating system flows through the exchanger's inner circuit; the mikveh water surrounds the outside. Heat passes through the stainless steel walls from the hot circuit to the pool water, raising the pool temperature to the required 34–37°C without any direct contact between the two water bodies. This separation is both a hygiene requirement and, in many communities, a halakhic requirement.

PRD is among the very few Israeli manufacturers producing stainless steel heat exchangers in-house. Most units in the Israeli market are imported — with the typical consequences: fixed catalogue sizes, long lead times, no local technical support, and no customisation. PRD custom-sizes every heat exchanger to the client's specific mikveh volume and heating load, working with you or your plumber to confirm the correct capacity before production begins. You do not need to calculate kilowatts independently — describe your mikveh and existing heating system and PRD advises on sizing.

AISI 304 stainless steel is standard — suitable for most water compositions and accepted by all major halakhic authorities for mikveh water contact. AISI 316 is specified for installations with high mineral content water or coastal saline conditions where enhanced corrosion resistance is required. The operating life of a correctly sized and installed PRD heat exchanger is 25–30 years, making it one of the longest-lived components in any mikveh heating system. Hot-side operating temperature up to 95°C; pressure rating up to 6–10 bar for standard plumbing.