Welcome to the first of a series of blog posts looking under the bonnet at the mechanics of Ecosmart, Nuaire’s proprietary fan controller. Ecosmart controls have been designed to be universally compatible across our entire range and can save contractors, consultants and end users a considerable amount of time and money when used to their full potential.
In this post, I want to tackle the business of controlling the running speed of fans and show some of the simple ways in which we can automate this process.
The Commissioning Board
Pictured right is the standard commissioning board present within every Ecosmart enabled fan. The “Min” and “Max” pots are used to set the operating limits of the fan; that is to say the fan will never run faster than the “maximum” limit and conversely never slower than the “minimum” limit. The most basic form of control is to simply enable the fan (more on this later) and set the maximum knob to achieve the desired commissioned speed.
It is important to remember before we proceed, that the speed of the fan is not to be confused with air volume; a fan speed of 100% will produce an air volume congruent with the actual measured duct pressure, the higher the pressure the lower the volume and vice versus. These values can be found by consulting the particular fan curve and reading off the volume against the measured pressure. When the fan is capable of delivering more volume than is required by the design against the measured pressure, we need to “turn down” the speed to achieve the design.
Working with Trickle and Boost
Ecosmart provides a simple mechanism for achieving a two speed arrangement, known as trickle and boost, the most common form of basic speed control. In this arrangement the fan has two commissioned speed settings, denoted by the “min” and “max” dials on the commissioning board. With the “trickle” switch turned on the fan will run at the speed set by the “min” dial whenever mains power is present, then when the fan is enabled it will move from the minimum setting to the maximum setting. When the enable signal is removed Ecosmart will wait for a period of time set by the run on timer (SL run on) before returning to the minimum speed.
Enabling and disabling the fan
The simplest and most common way to enable and disable the fan is to use the switched live connection. When live (L) is connected to switched live (SL) by a PIR, light switch or relay the fan is “enabled”.
Variable Speed Control
Taking trickle and boost systems to the next level requires the addition of some additional controls, to position the speed of the fan somewhere between minimum and maximum, this quite often can be based on user requirements or directly linked to room usage demand. Ecosmart makes this process incredibly simple. There are many different types of speed controller available, from the basic user dial (ES-UCF) and more advanced touch screen programmer (ES-LCD) through to discreet room condition controllers such as the CO2 (ES-co2) controller or temperature detector(ES-Temp2)
No matter which speed controller you choose, they all operate using the same “speed references” to set the running speed. Ecosmart divides the range between the minimum and maximum settings described previously into 10 distinct intervals of speed named 1-10.
When any of the Ecosmart Speed control devices are connected to the system (by simply pluggin them into the fans NET link socket), the device can select any of the 10 speed settings between min and max.
Automating Fan Speed
In the cases of “user” operated speed controlers such as ES-UCF and ES-LCD the user can simply dial in the speed they require, however automated controlers such as the temperature, humidity, and carbon dioxide detectors can link the fan speed directly to the demand in the space. As temperature or CO2 rises so does the fan speed, thus using the minimum amount of energy necessary to meet demand. When user dials and automated controlers are combined (simply by connecting both devises to the fan) users can choose their own speed or alternativly select “Auto”.
Combining user dials and automated sensors gives contractors and consultants the ability to create comprihensive control systems without the need for complex BMS controllers, giving the end users flexibility and simple automated controls.
In my next Myth Buster I will look at basic BMS integration using the Ecosmart Control interface (ES-CI)
If you have questions or feedback, feel free to contact Andrew Bott by email.