There is definitely something to be said for the
bliss of ignorance when it comes to energy usage. The more I peruse my graphs and produce increasingly granular reports on energy usage and commodity consumption, the more I feel a deep-seated urge to try to increase the efficiency of things.
Efficiency can be gained by numerous means, the simplest of which is to simply not use a resource.
Turning things off is probably the easiest goal to achieve with any automation platform, and Venturii is no exception. By using Passive Infrared and other forms of occupancy sensors, it is a trivial matter to have Venturii turn off the lights in a space when that space is unoccupied. I've even taken it a step further, utilizing a recent feature addition called Torx Pegs which allows me to do things at regular intervals. I've implemented a new set of instructions that cause Venturii to turn off
every light in the house during the day on an hourly basis, providing it is
very bright outside. This becomes a bit of a catch-all, especially for areas of the house that do not have occupancy sensors like the kitchen and dining rooms, areas that are often used and often left lit, unattended. Because the Torx peg restricts this sweep to once per hour, it's generally been received by the family as acceptable; if the lights get turned off when my wife is in the kitchen during the day, she simply turns back on the ones she needs to.
One of the more interesting means of improving efficiency involves more intelligence on the system calling the shots. Many of the appliances in my house have their own control systems built in that are designed to be reliable and robust given an unpredictable deployment environment and unforeseeable usage pattern. Many manufacturers have to build to the lowest common denominator, and while this accommodates the widest demographic of appliance users, it is usually sub-optimal.
For example, I have three refrigeration appliances in my house of six occupants. Two are the "normal" kinds an s with a fridge on the bottom and a freezer on top. Our third is an upright freezer. Two of these have been
Venturii'd - with at least a couple of DS18B20 temperature sensors installed within key locations. The third, our main fridge in the kitchen, remains a virgin.
Through my analysis of the temperature data collected from the basement's fridge and freezer, I've discovered a number of interesting things about their usage patterns:
- The basement fridge compressor runs about 50% of the time, quite possibly making it the least efficient of the three refrigerators.
- None of the refrigerators have any means to detect ice buildup in the condenser coils and run a defrost cycle every 24 hours whether it needs to or not.
- Occasionally the doors of said appliances get left open. This has forced me to install door position sensors on the fridge and freezer doors in the basement, with an alarm that sounds if either is left open for more than 60 seconds.
I am fairly confident that if I took over control of the compressor and defrost coil, I could make all three refrigerators operate much more efficiently, taking into account time of day, the number of times the door is opened, the cooling load of its' contents, and the ambient air temperature outside of each appliance. More on that later.
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