Economic aspects of the SMARThome systems
How much does a smart home system cost?
One of the most important criteria considered in the investment stage are, besides functionality, the ECONOMY of use. Investors usually only look at the construction budget forgetting the costs of future use of the system. In case of a smart home system it is worth it to integrate the lighting and heating. This requires only comparably small additional expenses.
Savings arising out of lighting control
In office buildings the savings provided by 'intelligent' light control are about 50-65%, and the costs of equipment purchased to provide these is returned after 3-4 years. In houses and apartments lighting besides its practical function also finds decorative uses and brings comfort - one will use a single group of lamps for 30-50 sq m of office spaces (which are switched together), and comparable residential space requires the use from one to even over a dozen different lighting circuits. These are factor that are so individual that it would not be proper to point to real world savings, even though they are there.
Savings arising out of heating control
Heating only when required. Thanks to independent temperature adjustment for every room one can save large amounts of energy (over 30%). A part of the rooms in the house is used only sporadically, thus they can be kept at a lower temperature; most rooms are only used a few hours a day (when returning from work and on weekends). In a typical installation they cause thus great losses of energy due to unneeded heating.
Period of return of investment
The calculations below were executed for three rooms of different capacity: bedroom, study and an open space (i. e. a living room with a corridor, kitchen and dining room). First, energy use and costs of typical heating were calculated for every room. The costs of KNX/EIB devices required to control the heating were also given (difference between the value of equipment controlling the heating and lighting, and the value of equipment controlling only the lighting). Below is a calculation of the depreciation:
|Yearly energy requirement in kW||5516||6058||15282|
|Energy costs||180 EUR||197 EUR||497 EUR|
|Savings in %||33,8 %||40,4 %||35,4 %|
|Equipment value||233 EUR||295 EUR||353 EUR|
|Linear depreciation period||3,85 yrs||3,71 yrs||2,01 yrs|
|Dynamic depreciation period|
(rate = 5%)
|4,26 yrs||4,16 yrs||2,14 yrs|
Depreciation takes place faster in case of larger rooms. This arises out of comparable value of control units for large and small rooms. The use of temperature control allows to eliminate 1/3 of the costs. At rising energy costs and falling interest rates, the depreciation period may be slower and future profits higher.