Hardware

Sunshade hardware

Overview

The main hardware used are the sunshades themselves, off course. All south and West facing windows have sunshades available, as well as our roof windows.

As automation of these sunshades has been a goal from the start, all sunshades are motorized and the required cabling has been installed during the building process.

Sunshades

In a well-insulated home, there is always a risk of overheating in the summer as accumulated heat can not escape to the outside during the nights.
The first thing to do, off course, is to make sure as little heat as possible is able to accumulate.

Although well-insulated windows already have an IR reflective film applied to the glass, they are still a major contribution to unwanted heating in the summer.
The effectiveness of this film can be found in the technical data of the windows under "Solar Insolation".

MythTV

I use a satellite dish with a TV Vlaanderen subscription on a MythtV backend.This works reliable for me.ssh-keygen -b 4096 -t rsa -C Moi_Keyssh-copy-id -i /root/.ssh/id_rsa.pub root@<MOI_Streaming_Box>

0-10V Analog output

Is PWM output the same as analog output?

No!
This is explained at http://arduino.cc/en/Tutorial/PWM

With the standard 5V output and a duty cycle of 50%, the output voltage is not 2.5V, but 5V for 50% of the time and 0V for the other 50% of the time. Standard the fequency of these pulses on Arduino is around 500Hz.



Temperature sensor interface

Sensors


I will use PT1000 sensors to measure several temperatures.
These are resistors where the resistance changes with the temperature, and with 0° C, the resistance is exactly 1000 Ohm.
The resistance change is also more or less linear with temperature change, which makes it easier to compute the actual temperature.

There are several ways of "measuring" the temperature, each with their own advantages and disadvantages.

Controlling underfloor heating

Equipment

What is needed to control the temperatures in the house:

  • Temperature sensor to measure outside temperature (TS_Outside)
  • Mixing valve to mix water of the correct temperature
  • Output(s) to control mixing valve
  • Temperature sensor to measure the temperature of the mixed water (TS_Floor_)
  • Temperature sensor to measure the temperature of the return water (TS_Floor_Return)
  • Output to control circulation pump (OUT_Circulation_Floor)
  • Temperature sensor(s) to measure inside temperature (TS_Inside)

Preventing Corrosion

Beause we are connecting tubes and equipment full of water to eachother, it is best to think about corrosion and how to prevent it.
Not when it has happened, but before we start designing the system.

There are different types of corrosion hapening in heating installation:

Galvanic Corrosion

http://en.wikipedia.org/wiki/Galvanic_corrosion

This occurs when dissimilar materials are used.
There are 2 things that need to be present in order to have galvanic corrosion:

  • There must be an electrolyte (The water that is being pumped.)

System overview

Energy sources

These are the components that "generate" heat.

Solar panels

The main source of energy will come from evacuated tube solar panels.
Evacuated tubes are less efficient in the summer, but more efficient in the winter as compared to flat pannels.

As there is enough sun in the summer, I don't care about the reduced efficiency.
I do care about the increased efficiency during winter months.
The panels are oversized in order to provide heat assistance in the winter.

Controller (Overview)

Design requirements

  • Standalone. The controller must be able to work autonomously.
  • Interfacable. The controller must interface with my homeautomation system.
  • Comfort. The controller must povide comfort.
  • Harvest as much as possible. The controller must try to harvest as much energy as possible.
  • Ecological. The controller must not consume energy when nog needed.

Modes

There are several modes possible.

  • Holiday. Only protection against frozen pipes, stuck valves/pumps, overheating, etc...

Underfloor heating

Introduction

The whole house is insulated very well and is heated by underfloor heating. (Hydronic)
In places that need a lot of heat and places that didn't have enough floorarea, the heating is augmented by wallheating. (Bathroom, etc...)

As the bathroom is not used for most of the day, the floor heating provides the basic temperature (20°c). The wallheating is not used.
When the bathroom is used, the wallheating is swithed on in order to have comfortable warmth (26°C).

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