Patent Application
20080027885
The preferred embodiment follows current trends in small, smart and easy-to-use, while paying attention to safety, reliability, data-integrity and battery-free operation to facilitate decade-long observations.
The preferred embodiment for measuring gas-energy usage is the CMOS-based electronic gas meter disclosed earlier (van Putten et al. 1974-5, 1985, 1994-7, 1999, 2001-2) based on a novel principle of thermodynamic anemometry (van Putten et al. 2006). The electronic gas-meter has been tested for safety in the form of a leak-test at 5 bar helium, which far exceeds the requirements of a domestic gas-meter. The same physical unit collects temperature data from both outside and inside, the latter possibly from multiple sensing points. The combined gas-meter, a wireless interface to temperature sensors and micro-electronics for data-archiving and data-analysis comprises the basic hardware of the VP-GEO unit. The concentration of these functions into one unit at the level of the gas-meter is motivated by requirements of reliability and data-integrity. For safe battery-free operation, the VP-GEO is powered by a standard outside adapter, connected to the wall or main electrical power cable.
The preferred embodiment for the temperature sensors is a solar-cell powered wireless unit with high-performance capacitor for short-duration energy storage. It serves to produce temperature measurements at low-frequency sampling and data-transmission rates to the VP-GEO. We estimate that an update frequency of about once per hour suffices for the intended weather-sensitivity analysis and interactive energy saving climate control algorithms. The same temperature sensor unit can be used for both inside and outside temperature measurements. Measurement of inside temperatures can further be performed at various locations, should differentiation for climate-control of different rooms be desirable. However, the inside temperature measurements need not be communicated to the VP-GEO but, rather, to a climate control unit.
In the preferred embodiment, a climate control unit (CCU) is centrally located and connected to the VP-GEO by wireless communication. The preferred communication channel is a widely used open commercial link, e.g., Bluetooth, allowing access by the user through a home computer, PDA or mobile phone. (These open channels can still be password encrypted.) The CCU serves serveral user-friendly and climate control functions. It presents snapshots of human behavior in gas-energy usage by real-time gas-flow measurements (
Specifically, the CCU features the following preferred interactive information and energy-saving features.
Visualization of gas-energy usage representing gas-flow measurements at a high-sampling rate on the order of 1 Hz (0.4 Hz in our field-test), complemented with various graphs of gas-energy usage histories. The histories including histograms of gas-energy usage partitioned over a various time-frames of the day, notably
(1) 0:00-8:00, (2) 8:00-16:00, (3) 16:00-24:00 hr. (3)
Weather-sensitivity analysis representing the quantities TCS and HEE, detailed in Eqs.(1-2). TCS can be presented as weekly, monthly or yearly averages. As a refinement, they can further be generated by data from each of the aforementioned time-frames (3) in order to detect the time-frame most sensitive to weather, and hence most amenably to energy savings. The TCS and HEE are archived for long-term storage to monitor the overall performance of the home and climate system, to serve as a reference in the validation of future home-improvements, to detect aging effects in heating system and home-insulation and to create an energy label for the home on the housing market.
Climate-control algorithms for an optimal balance between comfort and economy in energy usage:
T
inside
=T
0
+C*f(Toutside), (4)
where C denotes a correlation coefficient with the outside temperature Toutside and T0 a mean, minimal or maximal inside temperature. Here, f might represent a high-pass filter, to pass on the swing in outside temperatures while suppressing the mean in the same. In general, a Helios climate is subject to constraints to ensure safety and minimum comfort and health standards. Safety requires a home-temperature to remain well above zero degrees Celcius to prevent freezing while for health, a home-temperature must be sufficiently high to prevent a cold, humid home-climate to set in.
Some of the above features can be combined. The constants T0 and C in (4) can be changed when using the CO2-saving feature. On the basis of TCS, we can change them to target a specific CO2-savings. In the case at hand, TCS predicts a 5% CO2-savings upon lowering the daily mean inside temperature by 0.14K.
It will be appreciated that a climate control which results in little heating tends to produce a small TCS. (Notice that HEE is independent of climate control). In particular, zero heating, e.g., during warm periods of the year, produces zero TCS. Energy-saving typically follows an increase in C in (4), allowing a larger swing in inside temperature through an enhanced correlation between inside and outside temperature. Notice that the limit of no heating and open windows gives Tinside=Toutside. This limit can be used to define a maximal value of C.
The preferred embodiments presented here serve to illustrate the main VP-GEO concept of approaching energy savings through climate-control on the basis of advanced measurement and data-analysis of gas-energy usage and weather data. In practice, variations in the detailed implementation of the VP-GEO concept are possible, while remaining within the general frame-work set forth in the following claims.
