Heat Exchanger for Swimming Pool Heating: Sizing and Material Guide

Pool water is chlorinated, salted or otherwise treated and is highly corrosive to stainless steel at elevated temperature. Connecting a pool directly to a boiler or heat-pump loop would corrode the boiler and contaminate the heating water. A dedicated heat exchanger isolates the pool water from the heat source — boiler water, heat-pump water or solar fluid on one side, pool water on the other.

Pool chemistry (free chlorine 1–3 ppm, salt-water systems up to 4000 ppm) attacks stainless 316L within months, particularly at the elevated temperatures used in pool heating. Titanium plates and tubes resist pool water indefinitely and are now the default for indoor pools, salt-water pools, hotels, leisure centres and competition pools. 316L is sometimes used for low-chlorine residential pools but is not recommended for commercial service.

Pool heat-up load depends on volume, target temperature, fill temperature and required heat-up time. Maintenance load depends on surface area, cover, indoor or outdoor location, and ambient conditions. Typical commercial pool exchangers are sized for 30–150 kW for small pools and several hundred kW for large competition or leisure pools. The exchanger is then matched to the primary heat source flow rate and temperature — gas boiler (~80 °C primary), condensing boiler (~60 °C primary), or heat pump (~45–55 °C primary).

Small residential and light commercial pools usually use a titanium tube-in-shell unit — compact, low pressure drop, easy to plumb. Larger commercial pools use titanium plate heat exchangers for higher efficiency and serviceability. For very large pools with multiple heat sources, a plate-and-frame unit with bolt-on connections allows future expansion of the plate pack.

Install the exchanger with isolation valves on both sides, a thermometer pocket on the pool return, and a flow switch on the pool side to prevent dry running. Pool-side pump should run continuously while the heating loop is active to avoid local boiling on the plate surface. A pool-water temperature sensor downstream of the exchanger controls the primary-side valve or heat-pump compressor.

Send pool volume, target and starting temperature, required heat-up time, primary heat source and its supply temperature, and any chemistry specifics (salt vs chlorine). Jiangxing returns a titanium plate or tubular selection sized to your duty within one to two business days. Email Evan at jxmike@shheatex.com or message +86 173 1725 8304 on WhatsApp.