Fin MacDonald

Information on me and my current projects

Monthly Archives: June 2011

NSYCC Orientation

I spent the last three days doing orientation and training for the Nova Scotia Youth Conservation Corps. I will be working with the NSYCC on assignment with ThermalWise for the next two months doing green building research. Training camp took place at Acadia University in Wolfville. I was impressed with how many other people they employ. There are at least 50 others working on various environmental projects throughout the province. I found some crews who have work that relates to mine and we will be collaborating over the summer. I travelled up with Laura Hayes, who is my crew partner on the ThermalWise project, as well as Adam Hayter and Megan Borden who are working together with the Union of Nova Scotia Municipalities.

Training included a full day of first aid as well as an introduction to WHMIS and occupational health and safety. We also did several team building exercises and got to know one another. Lil MacPherson from the Wooden Monkey Restaurant in Halifax gave a spectacular presentation on global warming and the impacts it will have on our food supply. She taked extensively about sustainable food and why it is so important. This is of particular interest to me because it represents one of the credits in the LEED Operations and Maintenance certification.

The weekend wasn’t all work and no play. We managed to find time for a trip to the local swimming hole on White Rock Road and had some group musical jam sessions as well.

At the end of the summer we will get back together and present on our projects to each other. I’m really excited to see how everyone makes out.

Megan, Adam, Laura, and myself on the first day of training camp.

Group jam session led by Mr. Mustard.

Atlanticgreenbuilding.ca

Part of my new job over the next two months will be to maintain and improve the website www.atlanticgreenbuilding.ca . I will be working as part of a three person team with another student in Halifax and one in Newfoundland.

Atlanticgreenbuilding.ca provides information on green building products and services available in Atlantic Canada. This can be very useful to building owners and builders who are working to obtain LEED certification. Having all the information together for them in one place and verified by a third party makes planning easier. It also helps eliminate green washing, which is when a company pretends to be environmentally conscious but really isn’t.

The website features a virtual tour of green buildings in the area, as well as project profiles on them. The list is short at the moment but we will soon be adding case studies on some of the new and amazing green buildings that have been opened in the past year. This year we will have lots to choose from and that is evidence that green buildings are becoming the standard way of building. There have been several LEED for homes projects in the area over the past year.

Information on rebates is available to consumers on the website for Nova Scotia, New Brunswick, PEI, and Newfoundland. This section will be changing quite a bit for Nova Scotia because of the recent launch of programs by Efficiency Nova Scotia.

I know this project will be a learning experience for me and I am excited to begin. Researching the different products and services on the market will make me more aware of what options there are out there. By doing case studies of existing LEED buildings I will witness the different approaches that can be taken to achieve the different levels of LEED certification. I am planning to someday write my LEED AP exam and I think that this work will contribute to my studying for that as well.

NSCC Waterfront Solar Monitoring (Part 3)

Friday was my final day with NSCC Applied Research working full time. When I left Friday the monitoring system was not live. There are still some challenges to overcome with this very large project. When we replaced the wire with CAT5 network wire the system worked for a little while but then we started getting shorted bus errors. Because of the number of connections the resistance on the wire was too high. We will need to solder the connections instead of using quick connect clips in order to improve the signal. The WEL sends 5V over the 1-wire bus and because of the amount of quick connects we used for sensors runs we were getting too much resistance and noise on the line. We reduced the system to include only one of the evacuated tube collectors and the signal returned to normal. Once the soldering is done we can include the others again.

Our network connection is browning out as well. We are able to get a wireless signal on the roof with the equipment we have but we can’t keep it connected. This meant we couldn’t go live with the system. We will need to replace the antenna with something stronger. We have an access point on the roof for the solar photovoltaic monitoring and we may need to try connecting through that as well. That would require significant changes to the way the photovoltaic monitoring system communicates though so we would consider that a last resort.

I leave the project in the very capable hands of Dr. Alain Joseph and they rest of the crew. They will continue to move the project forward and I expect to see the system live this summer. I prepared a manual for them documenting the process of solar hot water monitoring using the WEL. I’m sure that will provide them with the knowledge transfer required for someone else to step in and continue the project. I have also agreed to offer them support on a part time basis as needed.

The experience of working on a large project like this one has been very valuable to me. We’ve worked through a number of different problems, and learned to anticipate things to go wrong. I know now that I shouldn’t expect anything to work right the first time. I also learned the importance of documenting your work properly, so that others can pick up where you left off.

Connecting a Pyranometer to the WEL

Getting a pyranometer to work with the Web Energy Logger (WEL) was a long process for us in the lab. A pyranometer is a device that measures the solar intensity in watts per meter squared. We used a 0-5V pyranometer from Apogee (http://www.apogeeinstruments.com/pyranometer/). This was a challenge because the WEL does not have a 0-5V input. We needed to convert the signal to 4-20 mA so that it could be read by the WEL. There is a benefit to 4-20mA though since it is a current signal and not voltage it doesn’t drop off when you use a long wire run. Originally we had an electronics student design us a signal converting circuit board because we had the tools to design and mill circuit boards here at the college. We found a company that manufactures boards like this (http://controlsignalconverter.com/) and it is much more practical to purchase them then make them in most cases.

When testing the pyranometer we noticed that the 4-20 mA signal would drop off around the 12 or 13 mA mark and saturate. The WEL would never receive the full 20 mA. We ran numerous tests with our equipment and determined that the problem was within the WEL itself. We spoke to the manufacturer of the WEL and he explained the problem and how to fix it. It requires some cutting to fix it. There are two zener diodes inside the WEL that need to be snipped off. To do this you need to remove the rabbit board network chip by wiggling it and lifting it at the same time. It is fairly snug so you will need to work at it to get it off. Once it is off you will have access to the zener diodes and you can snip them out with some wire cutters. You will see them next to the green 4-20 mA plug on the WEL sandwiched between two resistors. I took a picture of our board with them removed below and have identified where they used to be with a red circle. Once we removed the zener diodes it worked perfectly.

You need to scale the numbers in order to get the proper engineering units. We used the formula f(x)=78.125×-312.5 to convert the 4-20 mA signal into watts per meter squared. This was specific to the equipment we used so if you use a different pyranometer you will need to do the math yourself.

Pyranometers are important for research because they allow you to see how solar panel output changes with solar intensity. We are particularly interested in how solar performs in the winter time in our climate. It is cold but often the sun is shining. With a pyranometer in our system we will be able to draw more meaningful conclusions from our data.

    

Web Energy Logger Repair Job Today

Today I travelled to Bridgewater, NS to help an industry partner repair a Web Energy Logger (WEL) installation. The solar system uses 30 evacuated tube collectors to supply heat to an in-floor heating loop and dumps the heat in the summer time. Since I did not take part in the original monitoring system installation this presented challenges that were new to me. I had to look over the monitoring system to understand what it was doing before I started work. I needed to not just be able to understand how it was working, but also make sure that it was working. I located the sensors that were installed and tested their readings against readings on my temperature gun. I found one sensor that was not reading properly and replaced it with a new one. I also installed a current sensing switch on the glycol pump to detect when it is running. Since the in-floor heat loop has a constant flow rate we don’t need to install a flow meter to determine the heat provided by the system. I programmed the WEL with some thermodynamics calculations related to mass flow and it now calculates the energy output in kWh.

The repair job took just over an hour and I gained valuable experience in interpreting the work of others. Its easy to jump in and repair a system you set up yourself but when you are trying to follow the work of others it can be a challenge. Pictured below is the box containing the WEL and router (LEFT) and the building with evacuated tube solar collectors on the roof (RIGHT).

      

New job with ThermalWise and The NSYCC!

Today I accepted a new position with a company called Thermalwise that is funded through the Nova Scotia Youth Conservation Corps (NSYCC). The NSYCC provides employment and training to youth aged 17-30 in Nova Scotia in the field of environmental sustainability. They teamed up with ThermalWise to create two job positions doing green building research. ThermalWise is dedicated to helping reduce the impact of Atlantic Canadians on the environment by promoting and facilitating green building initiatives. They provide green building assessment, certification, consulting and education services to homeowners, building owners, developers and the general public.

My tasks will include:

• Highlighting entries in the database of green building products that are made in Nova Scotia.
• Maintaining the databases of green building products available in Canada, as well as community groups, businesses and government departments that provide green building related services.
• Creating a series of case studies highlighting innovative green building practices in both new and retrofit applications. Case studies will showcase not only the techniques but also the people involved. This will include interviewing these people.
• Creating a series of videos about green building projects in Nova Scotia.
• Developing a mechanism for the public to submit examples of the steps they’re taking in their own homes to improve energy efficiency.
• Organize and upload information to the website and update website through the summer.
• Maintain a blog on the project site that highlights the crews work and progress.

I am really excited for this position and I start on Monday June 27th.

          

Lock Out / Tag Out for Solar Photovoltaic

Today Travis, Gord, and Alain installed the Programable Logic Controller (PLC) system they designed to monitor the solar photovoltaic. Photovoltaic panels are the solar panels that produce electricity. Since there is electricity involved extra precautions need to be taken when doing work on the system. Lock Out / Tag Out is a procedure that involves turning off all sources of electricity and locking them in the off position with a padlock. It also requires a tag be added to the lock explaining what is happening. The key to the lock is kept so that only the person performing the work can turn the equipment back on. This prevents someone from inadvertently turning the power back on and electrocuting those doing the work. Gord Wilkie presented the procedure to Gary Williamson who is the facility manager and it was approved.

The lock out / tag out procedure was:
1) Open the solar AC disconnect and lock and tag.
2) Open the solar DC disconnect and lock and tag.
3) Securely cover solar panels with an opaque tarp.
4) Measure DC strings and ensure voltages are at zero.
5) Issue work permit.

Once the work permit was issued they installed the PLC monitoring system.

When they were finished the steps were:
1) Surrender the work permit.
2) Ensure all covers on monitoring box are in place.
3) Remove tarp from solar panels.
4) Close solar DC disconnect by removing the lock and tag.
5) Close solar AC disconnect by removing the lock and tag.

Safety is paramount when working with high voltage and I am happy to report that nobody way hurt. Their PLC system is working and we will start getting data immediately.

  

Solar panels covered by a tarp

NSCC Waterfront Solar Monitoring (Part 2)

The solar thermal monitoring project is moving along despite a couple of setbacks. We received the wireless equipment in the mail and were able to set up the wireless bridge to the schools wireless network. We used a directional antenna to improve the reception because the school’s wireless signal on the roof is weak.

We put a 12V deep cycle battery on the roof and we did a test run. It was able to power both the router and the Web Energy Logger (WEL). The battery is rated at 90 amp hours and the load for both the WEL and router is 0.4 amps combined. This means we are able to get over 3 months of power off the battery before we will need to swap it out for charging. This is good news because the battery is very heavy!

Testing with the pyranometer hit a bit of a wall initially. As I mentioned in my previous post the pyranometer measures the solar intensity in watts per meter squared. Since we are converting the 0-5V signal on the pyranometer to a 4-20 mA (milliamp) signal for the WEL we needed to scale the results. We did the math calculation and did a test run. We weren’t getting to the proper numbers in the upper ranges. Once we were confident the math was correct we tried numerous 4-20 mA devices with the WEL and had the same result. It really pays to have an electrical engineering student around when you are trying to troubleshoot electrical problems. Travis Keeping is our electrical expert at the lab and he a bunch of tests for us. In the end a call to Phil Malone from OurCoolHouse.com who designed the WEL was all it took to discover our problem. Turns out that the WEL has a defect and there are two zener diodes that we will need to snip out of the circuit and it should work fine after that. Phil also told us that new versions of the WEL will have a voltage port so we won’t need to convert the signal in the future. We have another WEL on order and it will have the voltage connection on it.

The wire we chose for the sensor wire run was cheap wire and it started giving us grief. We used a 75m run and it had too much resistance because it wasn’t twisted pair wire. Twisted pair wire helps to reduce the electrical noise on the signal. We started getting “shorted bus” errors on the WEL. I took the wire run down and we will be replacing it with CAT 5 wire, which is what is used for computer network cables. Once the new wire is installed we should be able to go live.

On the Road to Renewable Energy (Again)

Today we had a visit from Wayne Rostad at the research lab. Wayne is the former host of CBC Television’s “On the Road Again.” Wayne is building a house in Jeddore, NS and it is too remote to be connected to the electrical grid. He came by the campus to see some of our renewable energy equipment in operation and get some ideas for an off-grid system. He has a lot of wind at his location so we showed him some wind turbines in different energy classes to give him an idea of his options. We also showed him some solar photovoltaics as well because he is considering a wind/solar hybrid system. I hope we’ve left him with some good ideas for his home! I think there might be potential for LEED (Leadership in Energy and Environmental Design) certification as well. Since his home is not finished being built it is a candidate for LEED for Homes.

Wayne is no stranger to the camera so we snapped some pictures with him before he left.

Empowered Partnership – Success Magazine 2011

Each year NSCC puts out Success Magazine to publicize recent projects among students and staff. This year a project involving our lab was selected for printing! Dr. Alain Joseph who heads the Applied Energy Research Lab obtained a grant through NSERC (Natural Sciences and Engineering Council of Canada) to work to improve the performance of solar energy systems in Atlantic Canada. Dr. Joseph hired 8 students to help with the project over the course of the year. Travis Keeping from the Electrical Engineering Technology program and his instructor Gord Wilkie helped design a Programmable Logic Controller (PLC) to monitor solar hot water. The monitoring system was deployed in industry and will provide clues to the availability of solar energy in our climate. Since I came on late in the project my work involved examining low cost alternatives to the PLC system. My work using the Web Energy Logger (WEL) was based around trying to provide the same information as the PLC system. I believe it is important to have low cost alternatives because not every system is big enough to warrant the expense of PLCs which can be in the range of thousands of dollars. We are currently deploying both a PLC system and a low cost WEL on the solar equipment on the roof of the Waterfront Campus.

I have attached a scan of the article here.

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