3.2.2 Domestic heating and sanitation pumps

Domestic heating and sanitation pumps

Domestic heating and sanitation pumps are specially developed pumps, so called heating, water and sanitation pumps for the different pumping requirements in buildings, One of their general characteristics is a low level of noise and vibration, the requirements varying in accordance with the size of the building from a noise level of approximately 25 dBA for a private dwelling house, to approximately 65 dBA for pumps placed in a well insulated machine room in a larger building. These different pump requirements are covered by.

Heating circulation pumps

Heating circulation pumps for circulating water in a central heating system. Smaller sizes up to a power requirement of normally 100 watts are of the so called wet type, i.e. wet rotor motors, see figure 3.22b The pumps are mass produced with fixed performance, but in order to avoid noise in the piping system, their performance can be reduced by means of built in throttling and shunt devices, so called adjustable pumps. For larger sizes, pumps are used with the inlet and outlet connection placed in line and with normal types of silent running electrical motors, see figure 3.22b.

Figure 3.22a Heating circulation pump of twin design.

There are so called twin pumps, i.e. a pump unit with two pumps built as a unit ready for installation, for heat circulation pumps which are not too small. The pumps can be constructed together for parallel operation, see figure 3.22a, or series operation. The unit includes a non return valve system, controlled by the flow of pumped fluid so that either pump can be operated separately or together with the other pump.

Figure 3.622 Heat circulation pumps with in-line connections. The upper illustration is of the wet type. The lower illustration with a dry motor.

Hot water pumps

Hot water pumps for circulating hot water in larger buildings so that the hot water is almost immediately available when the tap is turned on. In contrast to central heating pumps, the parts in contact with the fluid are made of bronze, red brass or stainless steel instead of cast iron. Wet motors as well as dry motors are available, whereby special constructions are used for motor and shaft seals in order to avoid blockages due to furring up.

Other pumps in buildings are pressure boosting pumps (see multi stage pumps), groundwater pumps and to some extent also standard water pumps.