Environmental systems and controls

Overview

ESP-r offers a range of options for representing environmental controls. Ideal constrols allow constrained inputs to reflect the lack of information early in the design process as well as early explorations of demand patterns. Where users have specific designs in mind they must design and create networks of system components.

Ideal control representations

From a control engineer's point of view anything that does not take into account realistic time-lags and feedback signals are ideal control representations. ESP-r defines indeal controls via a sensor definition, and actuator definition and a control law schedule definition. hints.

Component approaches

Component based approaches to environmental controls involve selecting components from known component types. There is a considerable variety in the level of thermophysical detail within available components so users are often confronted by which-one-do-I-pick situations. On other pages you will find long lists of components offered.

ESP-r does not offer system templates. You are expected to design your network to approximate the design. Again this requires options for discovery of if-you-select-this-you-get-X. Long time users have figured out how to navigate the options, they will have a good intuition about what is contained in a template and what it will deliver. They will also have worked out working practices which match project needs to tool options. And some long time users know that there are some designs they cannot represent and no available work-arounds.

Control logic

Control engineers are facenated by how control logic can better deliver comfort or other desired outcomes. A control engineer might want to tune a virtual PID controller just as might be done during comissioning. Non-control engineers are often confronted both with jargon in simulation tools [link here] as well as environmental control regimes which they are unsure how to represent. Vendors often treat controls as black boxes which we, as users, might like a bit more clarity about.

Supervisory Controls

Buildings oven include high level controls to, for example, constrain peak electrical demands. Such global controls requires gathering information from the state of multiple controllers and sensors and then imposing over-rides on specific components to achive a high level goal.

Sensed conditions

It is not quite a secret that thermostats do not actually measure dry bult bemperature. And some locations of thermostats deliver poor control signals. ESP-r requires the user to define the location of sensors as well as a number of attributes.

Response characteristics

Real devices have time-lags. Perhaps it matters, perhaps project goals are not sensitive to such issues. Ideal control lack the time-lags.

Thermophysical states within components

Component may be black boxes or they may be designed to provide performance information about internal sub-systems. ESP-r includes a radiator with two nodes (case and fluid) as well as one with eight nodes.

Thermophysical states within ducts and pipes

Physical systems are linked by ducts and pipes and signals. Most simulation tools are not well suited to duct design or pipe design tasks. Experts can create explicit representations but normally we do not bother.