Daylight Harvesting; It’s A Bright Idea!
Daylight harvesting was mandated in Title 24 to cut wasteful energy in already well-lit areas. If utilized correctly, it can result in big savings and happy customers!
Say, for example, you have an office building that has numerous offices with floor to ceiling windows.
Those spaces will receive an incredible amount of light during sunny workdays, much more than all of their overhead lights could produce! If daylight sensors are installed and programmed correctly, those areas could see their light energy output cut by more than half during a typical 9-5 business day!
There are two types of daylight sensors commonly installed for daylight harvesting…
Open-loop and closed-loop. Open-loop sensors are designed to look directly at an ambient light source. Closed-loop sensors are designed to take equal amounts of ambient and artificial light sources. Also, there are daylight sensors that can control only one zone, or multiple zones. Having multiple zones would be useful where it shows primary and secondary daylit areas on your plans.
When considering placement of daylight sensors…
Make sure that if they’re open-loop, they’re facing outside and close to a window without any obstructions or interference by artificial light. A closed-loop sensor should be placed in the controlled zone with an equal amount of artificial light and day light. Make sure that the sensors are NOT placed where there is up-light coming from fixtures, as that could have a detrimental effect on the effectiveness of the sensor.
Because of their goal of cutting wasteful energy usage…
The California Energy Commission instituted Daylight Harvesting (130.1(d)) as part of the Title 24 code. If the code compliance forms for your project show the need for 130.1d in any space, you’ll need a daylight sensor to satisfy those requirements.
When your Title 24 acceptance technician is testing daylight sensors they will be taking readings of the amount of light in the primary (and secondary) zones during different times. The readings taken by the CLCATT will consist of night time, part light, and full day time to verify the fixtures are dimming the appropriate amounts for the amount of ambient light present. One of the most popular methods of taking those readings is with a light meter which reads the amount of light in the space utilizing a unit of measurement referred to as foot candle (fc).
Understanding when and where Title 24 requires daylight harvesting can be quite tricky!
There are quite a bit of prerequisites that must be met in a space in order to require daylight and also a few that would qualify for exemption. If you are in the design phase of your project, make sure to pick the appropriate type of daylight sensor for the space that will satisfy the end user, and also be Title 24 compliant!
If you have questions about which sensor would be right for your project, call us at 925-922-2606!
The In’s and Out’s of Occupancy Sensors!
One of the most important devices you’ll install for Title 24 is occupancy sensors. Having an area where the lighting turns off when you walk away will save the end user energy, and save them money, too! When planning out placement of these devices, you’re going to want to keep in mind a few of these tips!
Keep it at least 4’ away from AC supply!
If your occupancy sensor is located in a space where there is not enough room for a ceiling mounted sensor, place it diagonally from the AC supply or consider using a corner mounted sensor instead.
Position it centrally, but not too close to the entrance!
You want the sensor to pick up when people enter the room, and you’d also like it to function while they’re in their office chair, or in a meeting, or eating lunch. However, putting the occupancy sensor too close to the doorway could pick up outside motion from the hallway. Generally, sensors will have at least a 10’ by 10’ range in which they’ll detect motion. If the room is larger, ensure you have multiple sensors that reach all points of a room.
Set the time delay! – Automatic shutoff controls are also part of Title 24!
Whether you have a manual or automatic occupancy sensor, make sure that it’s all programmed in to the correct time delay. In the new 2016 code, it’s 20 minutes!
Make sure to test it!
Nothing can be worse than getting ready for your acceptance test and not checking to make sure what you installed is actually functional! Leave the room, close the door (and leave a note if you have to!) and be sure to time how long it takes for the lights to shut off. (Also, if you have controlled outlets, be sure to check those, too!)
Places that require occupancy sensors include offices <250 sq ft, multipurpose rooms <1000 sq ft, classrooms of any size, and conference rooms of any size.
For any other questions, including Title 24 design, consultation & acceptance testing, call us at 925-922-2606!
Lighting Controls Commissioning or Acceptance Testing?
“What’s the difference between Advanced Lighting Controls Commissioning and Advanced Lighting Controls Acceptance Testing?”
As we’re still in the infancy stage of Title 24 Acceptance Testing for Advanced Lighting Controls, we’re often posed with that question.
To explain, we’ll go over the chronological order from inception to completion. First, a system will be designed and a lighting controls package will be put together which usually includes the services for advanced lighting controls commission provided by the manufacturer.
Once all of the advanced lighting controls and components of the system have been properly installed, the electrical contractor will the submit a start-up request to have a technician perform the advanced lighting controls commissioning!
Advanced lighting controls systems are extremely malleable and may be used to achieve a multitude of desired effects far beyond what California’s Title 24 mandates.
Commissioning involves an advanced lighting controls field technician coming to the site, fully programming and testing the entire lighting control system to ensure functionality and operation within the design intent.
Today’s lighting controls commissioning agents need to be very versed in Title 24. Devices they could expect to find on the majority of systems can include but are not limited to: Occupancy Sensors, Daylight Harvesting Sensors, dimmer/scene Switches, Plug Load Controllers, Demand Response Systems, Lighting control panels, architectural dimming panels, and bacnet integration through segment managers. As all projects are different, not all of these devices may be present on every project. Once the advanced lighting controls commissioning has been completed, it’s time for your lighting controls acceptance testing!
Your acceptance technician will be ensuring functionality of all advanced lighting control devices.
During an acceptance test, your certified CALCTP-AT (Acceptance Technician) will ensure that the project is Title 24 compliant. To do so, your acceptance technician will be checking for multi-level lighting/area switching, daylight harvesting, automatic shut-off controls, demand response, and other requirements as shown on NRCC Title 24 code compliance forms and approved set of electrical plans.
In short the advanced lighting control technician will be performing: Plan review, Construction Inspection, and Functional Testing to ensure Title 24 compliance. The acceptance technician upon a successful completion will then supply the required acceptance certificates needed to pass your electrical final!
We hope this helps delineate the very important differences between commissioning and acceptance testing. Both are not just critical, but mandatory to ensure your project and Title 24 success! If you have any further questions, call us at 925-922-2606.
Lighting Control Systems for Title 24 Compliance
With Title 24 code mandating multilevel dimming for light fixtures, occupancy sensors or time scheduling, and other required features for commercial areas, we’ve narrowed it down to some of the most popular lighting control systems on the market to make sure your project is Title 24 compliant!
You’ll find that across all the systems, there are similar devices (just with different names). Generally, all these systems will have dimming switches, occupancy sensors, daylight sensors, devices to bridge the systems together, a ‘brain’ where all the devices are funneled into, and proprietary software that will allow the user total control of the entire system.
Occupancy sensors are not only incredibly efficient for the end user, they’re usually very easy to install. All have time delay features (up to 20 mins); and utilize passive infrared, and sometimes ultrasonic technologies.
Popular Occupancy Sensors:
Legrand/Wattstopper LMDC-100 Dual Tech Ceiling Mount
nLIGHT nCM xx RJB Ceiling Mount
Lutron Radio Powr Savr Occupancy Sensor
Daylight harvesting is necessary in areas that have a combined 120 watts or more in a primary daylit area. Under Title 24, these are necessary to shed the lights down to a set point that limits unnecessary lighting.
Popular Daylight Harvesting Sensors:
nLIGHT nCM ADCX RJB & nCM PC RJB
Legrand/Wattstopper LMLS-400 & LMLS-500
Lutron Radio Powr Saver Daylight Sensor
Dimming switches allow for end users to dim the controlled lighting down to their choosing. Under Title 24, multi-level lighting is required in most areas, making the dimming switch one of the most crucial parts of any system. Not to mention, it’s the one the end user will be tapping the most!
Popular Dimming Switches:
Lutron Maestro Dimmer & Switch
Wattstopper/Legrand LMDM-100 series
nLIGHT nPODM Family
Room connectors are the nucleus of the system. In most scenarios, all devices we’ve discussed prior will be connected by low-voltage cables to the room connectors. Check the respective system that you’re using for instructions on how to install.
Popular Room Connectors:
nLIGHT nPP16 Relay Pack
Lutron Power Packs
Legrand/Wattstopper LMRC Room Controller
All of the companies mentioned also have their own proprietary software and technology used in networking systems, and for programming in additional features (such as demand response).
End User Programming Software
Lutron’s Energy Saver Node (one of Lutron’s proprietary softwares)
Legrand/Wattstopper LMSM/Digital Network Supervisor
Why Does Title 24 Exist?
Two questions that are frequently overheard in the field are “What’s the purpose of Title 24?” and “What are it’s benefits?” We want to educate you as to what legislation prior, and up to Title 24 has been able to achieve. Also, we’ll delve into what it will provide as we look towards the future.
The state of California, as a whole, is 49th (out of 50 states & the District of Columbia) for per capita energy consumption. (That means we’re third best!) For a state that is home to more than 12% of the US population, that’s an incredible feat. It’s something that began back in 1974 with the formation of the California Energy Commission (CEC), and in turn leading the country in establishing appliance standards. It took another 13 years for similar code to be mandated at a federal level. Since mandating appliances in the 1970’s, California’s energy efficiency per capita has remained steadfast through today.
So you might ask, what’s California’s goal with doing all this Title 24 stuff? According to the CEC, their strategic goal is net-zero energy usage for nonresidential buildings by 2020; and net-zero energy usages for residential buildings by 2030. To reach these goals, one can expect the code to become more and more stringent as we approach those key dates.
As for Title 24 acceptance testing, it was introduced in the 2005 standards. A field technician was authorized to conduct the acceptance testing through the 2013 standards. Starting with the 2013 standards, certifications by ATTCP were required for HVAC systems & controls as well as indoor/outdoor lighting systems and controls.
The CEC explained “It is further the policy of the state…to reduce wasteful, uneconomical, and unnecessary uses of energy, thereby reducing the rate of growth of energy consumption, prudently conserve energy resources, and assure statewide environmental, public safety, and land use goals.”
In the end, the main benefits of Title 24 are for cutting down on the amount of excess energy we create, and lowering the cost to the end user by limiting the amount of energy produced.