Energy Saving Calculation

How much saving do I make by installing the Room-Service home automation system in my home?

The answer is not simple at all, because it depends on many things.

First of all, your habit to begin with: If you turn off the heaters and lights as you leave the room, and all other heaters and lights, room by room, before you leave home, or going to bed, well your room-manager (Daisy or Wally) can help you to do all that automatically, but they won't do any better in term of saving energy.

If your're any less "activist", like the rest of the population, the Room-Service home automation system can give you a considerable energy saving, effortlessly.

But how-much exactly?...

Again, it depends on many things: The isolation of the house, the number of hours of absence during the day, the level of temperature that you wish, the weather, or the climate where the house is.

To illustrate, we will do a simple estimation, with the following assumptions:

A two bedroom appartment with 4 heaters of 1500W each.

The climate, weather, winds, isolation and all other factors make it such that the heater is on in average 50% of the time to maintain the temperature at 20°C, and at 40% on 17°C, so we gain approximately 10% for the 3 degrees. (According to some studies, in average we can gain 7% of economy for each degree down on the thermostat).

A winter / heating period of 6 months (mid-octobre until mid-april).

10 hours of absence per day (from 8h30 when everybody leave to work, until 6:30 pm when you arrive at home).

6 hours of sleep, where one bedroom will be occupied and the others are empty.

So, let's assume for simplicity, that the thermostat of the Room-Service home-automation system is set at 17°C during absent and night-mode, when the room are inoccupied, and for comparison, before the installation of Room-Service home-automation system, the heaters are controlled at 20°C all day long.

The energy saving can be estimated as follow:

During the day: 4 heaters of 1500W x 10% (load difference between 20°C and 17°C) x 10 hours of absence = 6kwh.

During the night: 3 heaters at 1500W x 10%(load difference between 20°C and 17°C) x 6 hours of sleep = 2.7 kwh.

So, each day, the energy saving gain can reach 8.7 kwh per day, or 261kwh per month, or 1566 kwh for the whole winter.

With cost per kwh at 0,1325€, the energy saving of 1566 kwh per year can reach 207€!

(Tarif of electricity in france from a supplier as of 02/10/07, yearly fee of 120€ is not included in the cost per kwh calculation.).

This calculation, aproximative as it may, is nonetheless quite reasonable, since we've used some conservative asumptions:

- A heater, in general runs more than 50% to keep the temperature at 20°C, for outdoor temperature of 12°C (parisian region).

- The load difference between a thermostat of 20°C and that of 17°C (3 degrees lower), can be more than 10%, even further if the house is well isolated.

- And that you can obtain better result by setting the thermostat lower than 17°C for absent modes.

Don't forget that in case you have to stay at home all day, the room-manager will adapt itself, and keep the whole house warm while you're there.

And when you're on vacation, the energy saving can go even further, for the whole length of your vacation.

You can find the packs described in this article in our shop :

* Eco-pack 4 rooms

* Eco-pack 3 rooms

Or you can continue with the article "Low Cost Installation" to learn how to set up quickly and economically a Room-Service system in your home.