Chapter 4 - Properties of Water

One of the most important properties of water relevant to its use in hydronic systems is specific heat.

If the material changes phase while absorbing heat, its temperature will change.

The specific heat of water is high in comparison to other common materials. In fact, water has one of the highest specific heats of any known material.

The difference in heat capacity of water versus that of air is the single greatest advantage of using water rather than air to convey heat.

The density of water is not dependent on temperature.

It is often necessary to determine the quantity of heat stored in a given amount of material that undergoes a specific temperature change. An equation known as the sensible heat quantity equation, can be used for this purpose.

The quantity of heat absorbed or released from the material is expressed as Btu/hr.

The rate of heat transfer into or out of the fluid stream in equations is expressed as Btu.

The vapor pressure of a liquid is the minimum pressure that must be applied at the liquid's surface to prevent it from boiling.

When hydronic systems are first filled with water, dissolved air is present in the water throughout the system.

The heat absorbed or released by a material while it remains in a single phase is called __________ heat.

If the material changes phase while absorbing heat, its temperature does not change. The heat absorbed in such a process is called ________ heat.

Although it is not a defined scientific term, it could be said that water is almost _________ times more "thermally concentrated" than air.

Hydronic system designers often need to know the __________ of heat transfer to or from a stream of water flowing through a device such as a heat source or heat emitter.

The ___________ pressure of a liquid is the minimum pressure that must be applied at the liquid's surface to prevent it from boiling.

The viscosity of a fluid is an indicator of its resistance to __________.

The amount of air that can exist in solution with water is strongly dependent on the water's temperature. As water is heated, its ability to hold air in solution __________.

When a quantity of liquid water is put under pressure, there is __________ change in its volume.

The total liquid flow rate entering any portion of a fluid-filled (non-leaking) piping assembly will __________ the total flow rate exiting that assembly.

Incompressibility implies that liquids can exert tremendous pressure in any type of filled and closed container when they __________ due to heating.