THERE SHOULDN’T BE A LEARNING CURVE TO USE A THERMOSTAT
Just as lighting is a key aspect to enjoy any space, the client experience is also affected by the temperature of that space. The user experience of temperature control is often overlooked as it is seen as something difficult and out of many installers’ comfort zone.
In many luxury buildings, air conditioning is standard. However, these are typically commercial systems that require a significant amount of design and calculations. This industry is heavily commercial based and the idea of elegant, easy to use controls is often lost. With all the calculations, environmental impact and performance specifications, the consideration of the user is lost. The goal of the Zentium thermostat is to meet the concerns of installers and interior designers in a process that benefits everyone.
Superbly engineered commercial control systems lack a luxury user interface. For this reason, the industry seems to have adopted a less than ideal approach which is typically to hide the thermostat, not a customer centric design. We also see installations where a small probe is placed on a wall and wired back to a cupboard. This not only adds kilometres of unnecessary cables, it increases the risk of faults and increases costs of servicing. Probes can also get painted over or damaged. A hidden cost to these designs is that any changes a user wants to make means this must be programmed into the control surface, such as increase of the dead band, changing from Centigrade to Fahrenheit, fan control or disabling heating. This could mean a BMS or AV controls engineer call-out, and updates done to the core of the home’s control system. We all know what happens when that update is done on Friday evening!
This approach also means the homeowner, guests or staff have to understand the layout of a touch screen and adapt to your way of thinking. Whilst none of this is wrong and, in some situations can work, it is a solution to a problem that should not have existed in the first place if there had been an elegant thermostat fitted at the start.
The importance of styling is paramount in luxury developments, but the Zentium thermostat has added ease of use and integration to that.
We’ve all heard of the phrase ‘form over function’ but our philosophy is based on three pillars; form, function and integration.
It is not uncommon for a thermostat to have buttons that just don’t do anything. Maybe the feature has been disabled, maybe overridden; for whatever reason, this complicates the experience and can even lead to support calls as the user’s perception is that the system is not working. This is also true for the strange choice of symbols and cryptic hieroglyphics displayed on a screen.
The luxury client is not interested if it’s in frost protection mode, the floor has reached max temperature or in the angle of the ventilation grills. Yes, this information is important and should be accessible, but does it need to be so prevalent? The best user interface is one that from a glance the user knows what’s happening and how to use it.
The Zentiums’ digital crown is a universally understood control interface. Turn it up and the room temperature increases, turn it down it stops heating or starts cooling. Press the crown to change pages to fan speed, zone two or towel radiator.
There is no language barrier to this interface and different features that are being disabled can be altered. This allows the same thermostat to be used across spaces with different requirements without causing confusion.
Something that looks great often lacks the technical features that a quality installation requires. As an installer, your company profit is reliant on repeatability from the lessons learnt on previous jobs. Why have a different solution if you use Crestron, Lutron, Control4, Savant, Elan etc. Choose a thermostat that can be used with all these control systems so a repeatable design profile can be created. Additionally, it is important to consider its integration with BMS control systems such as NorthBT, Trend and Delta etc. Many AV installers shy away from this key part of an integrated smart building, in much the same way they stuff the thermostats in a cupboard. The broad spectrum of integration offered by the Zentium thermostat allows AV and BMS companies to work in a much more harmonious way. The benefits of this are the deep technical knowledge that BMS companies offer, allowing for a truly customer centric design.
THE DEAD BAND
We are all aware of the simplicity of underfloor heating. It is cold, turn the underfloor actuator ON, it’s too hot, turn the actuator OFF. The Zentium can create a third state, with no additional parts.
When a large slab of floor is being heated it builds up a huge amount of residual heat. If the supply of that heat is turned off only when the room gets to temperature, then that residual heat carries on heating that room beyond the target temperature. The worst effect of this can be oscillation, where the cooling kicks in to reduce the room back down, then the heating turns on in this fight between heating and cooling systems.
Traditionally this is dealt with by incorporating a dead band. A dead band is a temperature range at which neither heating or cooling occurs. This dead band can typically be two to four degrees wide! So a target temperature of 21 degrees wouldn’t trigger heating until it got to 19 degrees, or cooling until 23 degrees. While this technically does reduce the effects of the heating and cooling systems fighting, it also leaves the client a with a wide variation of temperatures within that space.
The Zentium has a few tools to help reduce this and give superior temperature controls. One of these is to create a third state in which during the last one degree of heating, the underfloor heating actuator will be modulated between on and off. This slows the heating process of the slab and reduces overshoots.
The second tool is the principle of a minimum floor temperature. The Zentium can be configured so the floor does not drop below a certain temperature. This means that a space does not have the same amount of potential difference between the current and target floor temperature. Imagine a fly wheel, if it is allowed to stop it needs a significant amount of energy to get it turning again, versus one that is just turning very slowly. The third tool allows the dead band to be different for cooling or heating so a larger band can be assigned to the cooling aspect than the heating. The dead bands can also set to half degree increments to improve responsiveness.
VRV & VRF INTEGRATION
At a given time, different locations within a room will vary in temperature. The temperature on a wall will be different to the temperature on the ceiling and different from a door architrave. The difference between these temperatures will also be fluid and not follow any linear relationship.
For this reason, when controlling a VRV or VRF unit that has its own room temperature sensor built in, the thermostat on the wall can be displaying a different temperature to that of the cooling unit. This leads to a situation where the cooling system can shut down or overrun beyond that of the user’s setpoint, because it uses its own built in sensor to govern when it turns off. This
leads to frustration and potential support issues as it’s not clear to the user why this is happening. The Zentium has a feature that can avoid this scenario as it can be set to use a ‘virtual’ temperature sensor. This allows the cooling system to effectively send its building room temperature reading to the Zentium wall thermostat. The Zentium then uses this as its own room temperature and display it to the user, while also using it to calculate its internal control strategy. This effectively ties the two systems together, creating a much tighter feedback loop between the two systems.
Commissioning a heating and cooling system can be difficult as this relies quite heavily on the actual weather conditions. One day you need it freezing cold to check the heating system can handle the demand, the next day you need a heat wave so you can ensure the cooling system does not collapse under the strain.
With Zentium’s virtual temperatures you can now simulate these conditions. A simulation in the BMS can then artificially set room temperature ‘readings’ to a desired temperature (this is not the setpoint, this is a fake room temperature). This in-turn triggers all the plant and systems into action. Creating such a commissioning plan after installation can really reduce the after sales visits on those wild weather condition days