## Glossary

### Glossary

Active power is the power converted to useful work of a machine or device.

The real power of a machine pulls from the mains, which is not the same as the effect of a machine converts into work is called apparent power.

Wastewater that is linked to the toilets ie heavily polluted.

Capacitance is the ability component has to store an electrical charge and is defined as the ratio between the charge and voltage. Capacity is measured in SI unit farad (F) which is equal to 1 Coulomb per second.

Is a logarithmic measure that indicates a relationship to a reference value. Commonly used in sound determinations, but also occur in other areas. The basic unit is actually Bel but used almost exclusively with the prefix deci ie 1/10 Bel.

Density volume or mass is an SI unit and is a measure of a specific substance density, ie mass per unit volume. A synonym for density that can sometimes occur is specific gravity.

Electrical current may also be called potential difference and displays the difference in the electric potential between two different points in an electrical circuit

Wastewater that is not attached to the toilet that drains from wash basins, showers, laundry, etc.

The idea of ​​a grey water heat exchanger is used to take advantage of the heat from the waste water and then primarily greywater and especially shower water. The principle is to preheat the cold water on the way to the mixer, thus reducing the need for hot water.

A coil heat exchanger in an air handling unit is based on the existence of two different battery i 'from the air and supply air that are linked to each other with a fluid circuit. The efficiency is around 55-60%. In addition to the relatively poorer efficiency demands up this type of värmeväxlig also that it has a pump with accessories. The main advantage of this type is when you do not want nor could any leakage between air currents that may be present in varying degrees in the other variants.

A plate heat exchanger in an air handling unit functions by air passes on each side of a heat transferring plate. The efficiency of a plate heat exchanger can get up to 90-95% depending on the model. The two most common variants of the heat exchanger is concurrent and countercurrent. Countercurrent flow exchanger generally has a higher efficiency than a concurrent exchanger. The disadvantage of plate heat exchanger compared to a rotating variant is that they are much larger and thus requires more space in the fan room.

A rotary heat exchanger in an air handling unit working by wheels with a large number of channels in slowly rotates formal air and outdoor air and transfers between them. The efficiency is around 80-85%. The rotating heat exchangers come in a number of different designs, such as hydroscopic which is ytbehandland in a manner such that besides the heat also transfers more moisture than a conventional heat exchanger. One disadvantage of rotary heat exchangers is that there is some air leakage between the supply and exhaust air which may make them unsuitable for the air smells a lot or is contaminated.

Inductance is a measure of the relationship between the magnetic flux and current. The inductance of a circuit prevents changes in the current that passes a coil. The unit of inductance is the Henry (H) or alternatively Weber per Ampere. 1 H is in most cases a very high induction of which is used for example mH etc. instead.

Joule is a unit of energy that is derived from SI units. 1 J is equivalent to the work required 1N carries over one meter. Older units of energy that is sometimes used is the calorie.

The likely flow is the flow that is expected to flow through a conduit at any one time. Likely flow commonly used in tap-, waste- and stormwater ie for flows that are not constant.

Newton is the SI unit of force, and is named after Isaac Newton. The definition of 1 N is that it is the force that is needed to give mass 1 kg an acceleration of 1 m/s2. 1 N can also be written as 1 kg*m/s2.

A measure that sets the design conditions for consumers in the usual tap- and wastewater calculations.

The reactive power is the difference between the apparent and active power, ie an effect that is not converted to useful work. This type of effect occurs in the inductive and capacitive loads.

Resistance is a value that represents the current limiting capability of an electrical circuit.

SI system ("Système International d'Unités") is an international standard unit of measurement system based on seven pieces of well defined basic units that can be traced to other devices.

Is a measure of how much power emitted to the environment. The sound power level is in most cases independent of the placement in the room.

Sound pressure is the the differences in the details of the atmospheric pressure that puts ear eardrums oscillate and perceived as sound.

Specific heat capacity is a measure of a material's ability to store thermal energy. SI unit for the specific heat capacity is J/(kg*K)

Also referred to as thermal conductivity and defined as the heat flow that passes through the material per unit time.