We’re about to begin construction on an editorial project that leapfrogs the silly little wall measles and tedious battery babysitting of the products being sold for home automation. We’ll be building an autonomous house – a sensor-rich environment where their data helps an intelligent controller determine the needs of both the occupants and the structure then effect the changes necessary to meet those needs without requiring human intervention. The automation is an outgrowth of its main goals: to be 40-years-maintenance-free and to reduce energy consumption.
We want the sensors to be next to invisible, mounted within or nearly flush to walls or ceilings or expected objects. We can handle the A/D or cold contact interfaces. But finding the right sensors has been challenging. For example, we want to place an overhead device in each room that can place every adult, child, infant or pet – and any heat source hot enough to flag a potential fire. While heat cameras are coming down in price, the grids on pyroelectric sensors are improving. Is there something at 32x32 or better that can provide us with the basic info we need? We’d love to hear about it.
Fire codes don’t allow garage doors to automatically open when carbon dioxide gets sensed for fear that the inrush of air will let flammable gases ignite. In the context of a 3-car garage, are there flammable or combustible gas sensors and CO sensors that can bring us a happy ending from a single sensor location? If not, what’s the minimum number that will allow reliable detection?
We are seeking ceiling- and wall-mounted ultrasonics in those garage spaces to detect the status of each of the 3 garage doors and parking spaces, on whether a car is entering or exiting and when it reaches its park-here position. Any candidates?
We also want to sense when the driver exits the vehicle my monitoring the motion of the driver’s door; and we want to be able to detect the slight cooling of the engine (or any other attribute) that can confirm that the engine is off. The house is well back from the street but we are equipping power and signal links at the driveway aprons; which sensors will provide the most reliable detection of incoming and exiting vehicles? What sensors might we add to identify “known” vehicles?
At the front door, we’re looking for a miniature presence sensor (perhaps PIR) that we can hide in the doorbell button – we want one bell to ring when a visitor pushes the button and another to ring when the visitor does not (also controlling record modes for the PoE cameras). The range hood shouldn’t need a switch but we’re challenged in finding a way to read the temperature of the cooktop below in an atmosphere that’s full of smoke and cooking splatter; remember, we’re trying to be 40-years-maintenance-free.
We’d like light switches to be unnecessary. That means monitoring ambient light, room occupancy, occupant movement patterns, TV and monitor screen glows and more. While we could do a lot of that with embedded indoor IP cameras, we set a policy of not allowing cameras indoors so we’d love to hear about sensors for these readings.
We’d like to do better at determining occupancy than motion-based sensors allow; how much do you move when you watch TV or read? How much does a sleeping person move? Thermal or IR sensing (especially with identified “bed zones” and abacus in/out logic) may be able to do better, or are there better solutions overall?
Occupancy sensing is also one component of the overall comfort equation. We would also like to be able to snag temperature, humidity and ambient light readings in every room. Control of the HVAC, ceiling fans and the fireplace should allow every place any occupant is, now or next, to be comfortable while relaxing the settings in vacated places and relaxing them even more when places go longer-term unoccupied. The goal is increased comfort with a reduced energy cost. And wow, are those control algorithms complicated!
We also want to be able to control shades to reduce sun glare. While we can predict sun glare using astronomical tables or through a custom AccuWeather API call, we’d like to find a sensor for each window that can tell us if sun glare is occurring and its elevation and azimuth. Is there, for example, a “fly’s eye” hemispherical photo sensor that can provide this data?
Temperature sensing both inside and outside any given window or wall will allow us to monitor the ongoing viability of insulation and give us early warning for addressing it. Current monitoring on major electricity user appliances can provide early warnings of incumbent problems while before they become less economical and less convenient to address.
Sensors will prove to be the secret sauce of any recipe for an autonomous house. Ours is not a remote control approach. We don’t seek to make a house a “fun” peripheral for a personal smart phone, or for evil-minded bad guys on the other side of the planet.
We need to make better use of existing technology for measuring temperature, humidity, distance, proximity, motion, occupancy, water flow, ambient light, incident glare, dangerous gases and more. With less than a year remaining to complete this project, we are eager to hear any suggestions that the always clever sensor-building community has to offer.
If you would like help Martin build his maintenance-free autonomous house, you can contact him via email at [email protected] or by telephone at 803-642-6664.