Blog: Coffee with Caleffi Q&A

Fall-off pressure is the reduction of pressure at the outlet of a pressure reducing valve (PRV), when downstream fixtures are open to allow flow through the PRV.  If, for example, a PRV is set at 70 psi, that is the static pressure setting and represents the PRV downstream pressure in a no-flow condition. As soon as fixtures...

Unless you know the actual system volume, it would be tough to partially fill with demineralized water and then pump in the appropriate amount of glycol. Buying full-strength glycol and mixing it at the jobsite using demineralized water from the Caleffi HYDROFILL...

The most basic, and typically the most economical, way to design a hydronic system for multiple temperatures is to use thermostatic mixing valves. This relatively simple concept can easily become complicated and expensive, however. Fortunately, Caleffi has some great resource material to help you design the right system for pretty much any multi-temperature...

With outdoor reset, the system does not run at one fixed water temperature. It is called outdoor reset because the water temperature is changed (or reset) based on a change in the outdoor temperature. This is used to match the heating system’s output to the heat loss of the structure. As the outside temperature lowers, the rate of heat loss increases...