04.12.12

Trade Talk: Custom-Integrated Energy Management

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'Energy management' seems to be the biggest buzzword in our market today.

 Everywhere I go, I hear people asking about eco systems and, more importantly, what a custom integrator like us can do to deliver a system that is energy efficient. This whole process started when the government introduced the Code for Sustainable Housing and set deadlines for achieving specific targets (www.planningportal.gov.uk/uploads/code_for_sust_homes.pdf).

 I believe that the home technology integration industry is sitting on top of a lucrative goldmine when it comes to energy management; it is becoming an essential part of the discussion with developers as they strive to deliver Code 6 housing (and therefore greater marketability of their product), and more and more important with private clients who simply want to reduce their home's running costs. But I also believe that we need to think carefully about how we design systems to deliver real and measurable gains in energy reduction.

Lighting
For me, the first port of call when starting to implement any energy efficiencies, is the part the code that specifically talks about lighting, the types of loads and, more importantly, movement sensing. Most manufacturers of intelligent lighting systems use a form of dimming that reduces the energy draw as the light level is reduced. This is a great start and is the first thing we mention in the sales process, but as a designer, you have to think deeper than that. 

As with all the component parts of a system, you must consider how the occupier of the house will use them, interact with them and expect them to work. To deliver a truly properly-integrated system however, you then have to work out how to take the onus off the user turning stuff off and stopping inadvertent waste. The highest level of a build is a Code 6, and most builders consider it almost impossible to build to this level, but even if they did, you are never going to find a Code 6 family that will willingly live a Code 6 lifestyle. Remember that statement because it is going to come up a lot in this piece!

So, when designing the lighting system, make as many rooms as you can be triggerable off occupancy sensors. Sure, put a keypad in too, but let the lighting system manage itself. Some manufacturers make an occupancy sensor with a built-in lumen level meter; this allows you to then do some constant light level stuff, which will reduce the energy draw even further. One word of caution though: use LEDs and low-energy fittings wherever you can, but make absolutely sure they are dimmable and controllable, and double-check that the loadings are high enough to allow the dimmer packs to work, as some LEDs do not work because they go below the minimum load requirement of a driver.

Heating
The next think to look at is the heating system. While the choice of good systems is limited, some control system manufacturers offer their own thermostats and there is a good standalone system from Honeywell. Whichever system you choose, obviously it must be controllable and settable via your control system, but to offer some credibility, you will need to look to something a bit more clever than an IP-controllable thermostat that in reality can just call for heat.

Sure, it may be cool to be able to set room temperatures remotely and turn heating off and on when away, but think about this: most heating systems take time to heat up and take time to cool down. If all the heating system does is call for heat until the thermostat hits 22 degrees and then stops, the latent heat in the system will still continue to heat the room after it is turned off, taking the temperature up to perhaps 25 degrees. Then it starts to cool, triggering the thermostat to come on again at 22 degrees. The problem is that the heat continues to drop whilst the system gets going and probably drops to 18 degrees before it heats up again. You end up in a massive cycle of too hot or too cold, which is wasteful of energy.

The remedy is to use a system that offers some form of logic that 'learns' the thermal dynamic of the room. This will eliminate the massive hot/cold cycle and enable the system to work more efficiently. Remember the non-existent Code 6 family? Again, you have to take the ability to use the system inefficiently away from our wasteful owner. For example, because of the heating cycle, I've seen instances where, when the room gets too hot, the occupant opens a window to cool the room! Yes, this cools it down, but the heating then works overtime and wastes masses of energy. So how about putting sensors on the windows that link to the control system and cut the heating as soon as a window is opened?

Other Energy-Consuming Devices
Lighting and heating are the obvious areas in which to look to save energy, but AV systems and all of the other stuff are also adding to the fuel bill. Think about the power use of each individual device, and more importantly, the control options of it. For example, LG just removed RS232 control from their TVs, which means all we can now do is use their IP protocols over their Ethernet port. The problem is that the Ethernet port is dead once the TV is off, which means we cannot wake it up with a control system, and therefore have to leave it on standby! When I started to look into other devices round the home, I was stunned to see the power draw of some of the subwoofers that we specify. So just think carefully about the products you use, and ask yourself whether there is an alternative that uses less energy than the one you are familiar with.

Programming and Integration
Having selected the greenest systems on the market, added them to a ground-source/solar/rainwater system that's in the house too, and bundled them into one easily-controllable system, you end up with the problem of having sensors all across the house of varying shapes and sizes. Why not look at this potential wall- and ceiling-acne and consider which sensors can be used to communicate with other systems, and what benefits you may gain by making these devices talk to each other?

A classic example is the burglar alarm. A link to the alarm system can tell the home that the client has gone out or has gone to bed, This allows you to program for example, that when the alarm is set, the system will turn off every light in the home, and if intelligent power sockets are used, every non-essential device is turned off too. The alarm window sensors can be used to tell the heating system to cut off when a window is opened, saving on having two sensors on each window. Going back to the Code 6 family, what about having the occupancy sensors talk to the power system so that when your son leaves his bedroom, not only do the lights turn off but his TV too, as well as his games console, music and all the other stuff he leaves on?

This energy monitor screen is part of Niko's energy monitoring system and gives an easy-to-understand overview of what is happening in a home.[/caption] If you can try and build some sensing devices into the system, such as clamps on power feeds, flow meters on water and the feedback you get from the solar/PV/rainwater systems, you can then make a dashboard page on your control system that allows the homeowner to really monitor what their home is doing.

New Build and Retrofit
It is easy to specify all of these systems if all you have in front of you is an initial set of plans, but what about a retrofit job? In fact it is not as bad as you may think. There are wireless dimming systems which work very well. There are thermostats that replace the top of a radiator valve and allow you to adapt an existing heating system, and I have seen some clever RF and powerline Ethernet sockets that can be centrally managed too. So just because you are faced with an existing and beautifully-finished home, don't be put off - it is all achievable.

Conclusion
Unless you specialise only in home cinemas, energy management is going to be one of the biggest sectors of our industry, but don't think that all you need to do is buy and install something that says it is energy efficient. You will read about various manufacturers having wonderful products that use less than 1 watt or that do something funky and clever, but don't believe the hype. It is not enough to simply specify a product; you have to think about how best to control it and integrate it with other systems so that it makes sense within the context of your client's lifestyle. We should all offer an energy-aware component in our systems to every customer, whether they be private clients or developers. Using an automation system to monitor and control energy use around a home will enable developers to build to a higher code level and not only achieve the targets set for sustainable homes but gain a real marketing advantage when it comes to selling the finished unit. Ultimately, we must all do our bit for the environment, so planning for practical energy saving not only shows your customer that you care for their wallet, it gives you the satisfaction of helping the planet and future generations too.

Kris Hogg is the Managing Director of Konnectiv Group Ltd, and a member of the board of CEDIA Region 1. Konnectiv is an an award-winning integrator and recognised as a leading expert in the design of energy-saving home automation systems.

www.konnectiv.com