Valve Sizing Tool

How does a TMV work?



The animation above illustrates how a thermostatic mixing valve works.

Further explanation is given in the Useful Documents list.

All Horne thermostatic mixing valves (TMVs) operate on the same principle by mixing hot water with cold water to deliver blended water at a pre-set temperature. In normal usage, where domestic hot water systems utilise a thermal regime for the control of water-borne pathogens such as Legionella, the hot water supply is typically around 60°C. Kitchens and laundries often need higher water temperatures for cleaning and washing purposes. Maintaining the hot water system at even higher temperatures can increase overall hot water capacity (as it is mixed with a greater volume of cold water, via a thermostatic mixing valve at the point of use).

Water above 48°C, however, can scald and so it is mixed with cold water, at the point of discharge, to produce a flow at a safe and comfortable temperature of 41°C.

In the 1920s, we developed the first thermostatic mixing valves or TMVs (which we called a 'blender' at the time) to be manufactured and sold in the UK. Now we supply TMVs in a range of sizes from DN15 to DN50 for a variety of applications including healthcare, nursing and sheltered accommodation, education, sport and leisure, housing associations and secure hospitals and prisons.