Commissioning - August 2016
Its the end of August and the team is putting the finishing touches on the Nature Center. The mechanical system is up and running, and testing, adjusting and balancing (TAB) is complete. Commissioning is the final check of the system before the building is turned over to the Nature Center. Much of the functional testing happens through 'the graphics', the user interface with the Building Automation System (BAS). By manipulating set points and conditions, we are able to test the system's functionality in various modes, including failures.
The Floor Plan graphic gives the nature center a quick overview of the space - temperatures, humidity, and CO2 level in the auditorium. From there, the user can dig into one of the systems - whether its a particular room, or a piece of equipment in the mechanical room.
Clicking on the Classroom space, in the bottom right-hand corner of the Floor Plan, will bring up this graphic for HP-6. This graphic gives detailed information about what the unit is doing - what the current temperature set point is, if the unit is in heating mode, cooling mode, or dehumidification mode, compressor outputs and other system statuses. The 'Occupancy Mode' is a key energy saving feature, and it can be commanded from this screen.
Each heat pump has four basic occupancy modes:
Occupied - The daily schedule is set to have the units run during normal working hours, to the most comfortable temperature. The fan runs continuously to deliver fresh air to the space.
Occupied Standby - During the day, if the lighting occupancy sensor in the space does not detect anyone, the unit allows the temperature to drift slightly to save energy.
Unoccupied - During unoccupied times, the fan shuts off and the unit only runs to minimally condition the space. This allows for the most energy savings.
Occupied Override - If someone comes in to the space to work while the nature center is closed, they can push an override button to bring the unit back into occupied mode for two hours.
The ERV also has its own graphic, which monitors the filters to determine if they need to be changed, and also monitors the fans for failure. This is a very useful graphic for understanding how an Energy Recovery Ventilator works.
The premise of an ERV is to use the conditioned air from the building to temper outside air being brought into the space. Air has to be exhausted from the restrooms, but work has already been done to condition that air to room temperature. Air from outside might be 0°F or 100°F, so an energy recovery wheel is used to transfer heat from the exhaust air to the incoming air. As you can see in the screenshot below, exhaust air from the space enters the ERV at 72°F. Outside air enters the ERV at 81°F. The energy recovery wheel spins between the two airstreams, using the room temperature exhaust air to cool off the wheel before it extracts heat from the outside air.
The Heat Pump Loop Control graphic shows the pumps controlling the flow through the geothermal loop. When a heat pump is running, a valve opens to allow glycol to flow through it. As more heat pumps start running (on a warm afternoon, for example) the pump must speed up to provide enough flow for all the heat pumps. A variable frequency drive (VFD) is used to modulate the pump speed, slowing the pump down when possible to save energy.
Heat Pumps - Summer 2016
A ground-sourced geothermal heat pump system was selected for this building as the most energy efficient option. The geothermal lines may be buried under the prairie, but the heat pumps can be seen in the mechanical room and closets.
This heat pump is in the Project Room closet. As you can see from the arrows, the supply and return water lines to the heat pump have been installed and are partially insulated.
Here's a close-up view of the valves. The valve on the left, on the 'leaving side' of the heat pump, is called an autoflow. Independent of other variables in the system, as long as the system pressure is within a specified range the flow through the valve will be exactly what the heat pump needs.
The valve on the right, on the 'entering side' of the heat pump, is also a strainer. The system was cleaned and flushed, but over time pipe scale or other debris can enter the glycol, which could lower the efficiency of the heat pumps coils if not caught upstream at the strainer. Both valves also act as shutoff valves, allowing the unit to be isolated from the rest of the system for service.
HP-1 is located above the Men's Restroom and serves the Exhibit Hall space. The white box on the front of the unit is its wireless communication device, tying it in to Trane's central panel.
The heat pump below serves the office area, and is located above the mudroom.
Ductwork is also starting to take over the mechanical room. Some of the ductwork shown is delivering ventilation air from the Energy Recovery Unit to the spaces, some is pulling exhaust air out of the restrooms, and some is moving recirculated air from the central corridor.
The Mechanical Room - May 2016
The Indian Creek Nature Center’s mechanical room is not like most mechanical rooms we’re used to. Instead of being tucked away in a basement or back room, this mechanical room has a glass wall so visitors can see the equipment. An interactive touch-screen display will be on the wall next to the mechanical room, allowing visitors to see data on the energy consumption, solar production, and water consumption in real time. It will also have information about the pumps, heat pumps, energy recovery ventilator and geothermal system, to be used as a learning tool. For now at least, the mechanical room is a work in progress.
During a mechanical site visit, our Commissioning Agents are comparing the installation with the plans and specifications. First, the components are reviewed – are the shut-off valves, check-valves, bypasses, and other hydronic specialties configured as shown on the drawings? Have di-electric fittings been used when two dissimilar metals are joined? Are sensor wells in the correct locations? Next, the installation is reviewed – are the components accessible? Has the piping and ductwork been hung adequately? Has each unit been isolated from the structure, so vibration is not transferred into the building? Any problems identified at this stage can typically be fixed relatively quickly, as opposed to identifying problems after the systems are up and running.
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The piping system is installed with pressure relief valves and air vents; these allow the system to relieve pressure before damage is done to the piping and components. In this picture you can see various components of the system, including an air separator (tall red cylinder) and wells for pressure gauges, temperature sensors, and a meter to measure flow.
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Here is the copper line from the relief valve piped back to the glycol feed tank. The system is filled with propylene glycol, so these relief valves are piped back to a glycol holding tank. Propylene glycol is a food-grade additive that lowers the freezing point of the fluid to about 15°F. This ensures glycol is not wasted and washed down the drain.
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This is the geothermal manifold, where the geothermal lines come from outside, through the floor into the mechanical room. Each loop has a balancing valve so flow can be distributed evenly throughout the well field. The yellow-handled valves on the right hand side are where the tanker truck will be connected to the system to fill it with glycol. That will happen in early June.
Roofing Details - April 2016
The roof and drainage systems are critical to the Living Building Challenge program, because the amount of water collected to recharge the Silurian-Devonian aquifer must balance with the amount the nature center pulls from its well. This strategy goes back to the Living Future Institute’s goal of shifting the construction paradigm – instead of diverting the water into storm sewers and concrete culverts, the water is retained on site to replenish the regional aquifer. The retention pond, deck and pergola are well underway.
There is a large underground storage tank which holds enough water to supply the fire suppression sprinkler system for a specified period of time. This allowed the design team to size the well for typical daily use, and will make water readily available without stressing the aquifer in an emergency.
You won’t see much of the roof from the main entrance, because the southern exposure will be covered with solar panels, but the ICNC will have a PAC-CLAD standing-seam metal roof.
There are multiple components to the metal roof. Before the sheet metal is installed, an underlayment is applied to the SIP roof panels to provide a waterproof barrier. The metal roof acts as a water shed, protecting this underlayment from UV exposure and the elements. The underlayment protects the roof from ice and water, were it to infiltrate behind the metal panels. Together, the system is designed to last 30 years. Titanium PSU-30 is considered a 'self-healing membrane', which means that it will form a seal around nails or staples driven through it.
Once the system is in place, the manufacturer must inspect and certify the installation in order to receive a warranty. SystemWorks worked with the installers as a third-party reviewer ahead of this inspection, referencing the manufacturers guidelines to ensure all areas were properly installed. Mother nature also helps
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Some of the roof lines were difficult to detail. In this example, an extra section of membrane was added to protect the valley membrane that laps over the field sheet. |
This image shows how the underlayment was 'shingle-lapped' in the valleys.
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South elevation 'doghouse' framing. After this picture was taken, additional sealant was used to fully adhere the membrane to itself and to the green air barrier around this complicated detail.
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To prevent moisture infiltration, pipe boots have been added to mechanical penetrations. |
The majority of the curtain wall has been installed at the south entrance.
Progress Inside and Out - March 2016
As the weather improves, progress has sped up at the Amazing Space project. The heat pumps have arrived on-site, and are being hung. Ductwork has started to arrive on site as well. The heat pumps will be connected to the building's piping system via flexible 'hose kits'. The braided stainless steel lines absorb the vibration from the heat pump's fan and compressor, and prevent it from being transferred throughout the building. Each 'hose kit' has multiple components; on the entering side, there is a mesh strainer that keeps any debris in the glycol from clogging up the heat pump's coil. On the leaving side, there is a balancing valve which ensures the correct amount of glycol is flowing through the unit. The heat pumps will be above the ceiling throughout the nature center. The heat pump shown below is above the staff office area.
Progress is being made on the interior finishes as well. Drywall is going up, and acoustical panels are being set on the ceiling (left side of the picture below). The trusses in the picture are what you'll see when the building is complete!
At the peak there are north-facing windows which run the length of the building. These windows are north-facing, and provide natural light to the interior spaces. This strategy is known as 'Daylighting'. By using indirect natural light, the electric lights can be dimmed to save energy, while keeping the space bright.
Here's another look at the outside of the building. The roof underlayment is being prepped, and the stonework is almost complete.
Walls and Windows - March 2016
Installation of the air barrier system is underway, and construction is moving quickly with the nice weather. Each envelope component is quickly covered by the next as the crew works to complete the exterior facade. Success is in the details, and there are several things being done at the Indian Creek Nature Center that demonstrate quality workmanship and a dedication to making this building as energy efficient as possible.
- Compatible products are being used to seal joints, holes, and other discontinuities in the substrate material. The picture below shows the gaps between sheets of OSB plywood have been prefilled in preparation of the fluid-applied air barrier.
- "Detail Membrane" is being used. Detail membrane is a sheet-good type product designed to cover otherwise hard to handle features like the columns, window frames and corners.
- Primer is being applied well past the leading edge of the air barrier membrane. The dark green color is a visual indication that the substrate surface has been primed. Extending it well past the leading edge, as shown in the image below, allows the products to be layered and fully adhered.
- Mortar netting is being used. MortarNet is a plastic mesh that goes along the bottom of a masonry wall. Rock is porous, so block walls – bricks, river rock, etc. – all have a space behind the blocks where water can condense and drain out the bottom. Without this ‘micro-climate’, water would freeze behind the bricks and push them off the wall. As the rock walls are assembled, mortar inevitably falls behind the blocks. Without mortar netting, this would clog the drainage plane and hold moisture behind the block wall. Mortar netting is shaped like a V, designed to catch the mortar droppings on two levels while allowing water to drain all the way to the bottom.
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Diagram showing how mortar netting catches droppings at different elevations behind the wall. |
This image is looking down behind the block wall around the column pictured above. The mortar netting is blue.
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Taking Shape - January 2016
Exterior framing is complete, SIPs cover the roof, and the team is preparing to apply the fluid-applied air barrier. The walls are constructed from the inside out - as you can see, the OSB plywood sheathing is complete, and cut-outs have been made for the windows. Next, the air barrier will be applied directly to the sheathing. Once the air barrier is complete, the outbound insulation and exterior facade will be installed.
Air barrier products require specific conditions for installation. Moisture content in the the substrate, in this case OSB plywood, and temperature of the product, substrate and air, are two major considerations. Ryan Companies will be maintaining a log of outside temperatures throughout the air barrier installation, as temperatures may dip below the acceptable criteria and progress will have to stop until it warms up. The product must be stored above 40°F and applied above 25°F or it will not properly adhere.
The air barrier is just one part of the Building Envelope. Each product must be reviewed for compatibility with other products in the system -- certain caulks and sealants won't adhere to others, while some products may adhere now, but will slowly corrode over time. SystemWorks met with the installing contractors, design team, and product manufacturers representatives to talk through specific 'tie-in' points where the air barrier meets another piece of the building envelope, like the roof or a window, and discuss what products can and cannot be used together.
During installation, SystemWorks will be reviewing the substrate preparation and application. The fluid-applied air barrier is like a thick paint; nail holes have to be sealed properly, and gaps greater than 1/4" have to be filled in order for the product to be continuous. Fluid applied air barriers have a specified 'wet mil' and 'dry mil' thickness. The 'wet mil' thickness is the depth of the material when it is first applied. For the product being used at the ICNC, it is 90 wet mils (or 9-thousandths of an inch). Once the product has cured, its thickness is measured in 'dry mils', and must exceed 45 thousandths of an inch. Wet mil thickness is measured with a simple depth gauge, while dry mil thickness is determined by cutting a sample and using a device called a finescale comparator to measure its thickness.
In the picture below, you can see the trusses supporting the SIP roof. The crew did an exceptional job installing the SIPs, making sure each panel interlocked tightly with the next. You can also see interior walls are being framed and electrical outlets are being roughed-in.
Under the Floor - November 2015
The floor is the first side of the ICNC to be finished. Rigid foam board extends down 3' below the level of the concrete slab, on the inside of the footing. This isolates the concrete slab from the temperature - and the frost - of the ground around the building. The top of this foam board is beveled, as you can see in the picture below. 3" thick foam board is also placed along the interior perimeter of the building, further insulating the building from the ground. Mechanical, electrical and plumbing lines run below the concrete slab. Anywhere they penetrate the foam, spray foam is used to re-seal the hole and maintain a continuous thermal barrier.
There is also a vapor retarder below the slab, preventing moisture drive through the floor. Just like with the foam insulation, any penetrations through this polyolefin sheet were taped, and the edges are left long so they can be tied into the sealants above the concrete slab. Below is a picture of the vapor retarder being installed.
Moving Dirt - September 2015
After months of planning and design, the site-work has begun! There's not much commissioning work to be done right now -- we'll check back when the foundation is poured.
The building pad is taking shape in the northwest corner of the Paul Christiansen Prairie, and the locals have been checking it out:
Designing A Living Building - June 2015
Rather than specify oversized equipment to compensate for infiltration, heat loss and other unknowns, this building's envelope components were built into an energy model so a comprehensive analysis could be performed. With a tight building envelope that is completely thermally broken, Design Engineers was able to 'right-size' the building's mechanical equipment. Reducing the size of the equipment does a number of things: it reduces the initial cost of the equipment and it reduces the energy required to run -- which in a net positive building directly impacts the number of solar modules required for the project. Not only that, but people in the space will feel a difference too - 'right-sized' equipment runs more steadily, dehumidifies more effectively, and is able to hold the desired temperature better.
This is a typical architectural detail - The wall in this particular section is 8" thick, insulated with 8" of rock wool inside the cavity, and an additional 1" extruded polystyrene insulation board on the exterior. Behind the exterior insulation, against the wood sheathing of the wall cavity, is a fluid applied air barrier. The vapor retarder extends down from the top of the wall to the slab, where it ties into the underslab vapor barrier.
The roof of this building is made of Structural Insulated Panels, or SIPs, which sit on top of the trusses. By tying the wall insulation into the roofing system, SLA has created a layer of continuous insulation, enveloping the building. Insulation also extends down the footings and underneath the perimeter of the slab, in an effort to maintain continuous insulation on all six sides of the nature center.
All of these components are designed to keep the conditioned air inside the building, and isolate it from the conditions outside - whether its below freezing and snowing, a spring storm, or a hot and humid August day.
What is a SIP?
A SIP is factory-made building material, consisting of a foam core sandwiched between two structural materials, typically plywood. When properly sealed, SIPs have a very low air/vapor permeability and become part of the continuous insulation as well as the vapor retarder and air barrier systems.
Learn More from the SIP Association Here
What is the Amazing Space Project?
Indian Creek Nature Center (ICNC) is a place where people connect with the wonders of the natural world. ICNC opened in 1973 as Iowa's first nature center, and nearly 2 million people have visited since it first opened. The nature center promotes a sustainable future through environmental education, demonstrating land protection and restoration, and encouraging responsible interactions with nature.
The concerning state of Iowa's natural resources emphasizes the importance of the nature center's mission. Iowa has lost 99.9% of its original prairie and has less than 3,000 acres of protected virgin prairie remaining. Over 6 million acres of wetlands have been reduced to a mere 70,000 acres. Ditching and straightening have already eliminated over 7,000 miles of natural stream course. While natural areas and agricultural land are being swallowed up by development, private woodlots and grasslands are rapidly being converted to cropland. ICNC is a leader in today's protection movement.
An Amazingly Popular Space: Over 17,500 youth participated in 440 programs offered by ICNC in 2013. An additional 40,525 people visited the nature center, for programs or just to enjoy the trails.
The Living Building Challenge
The goal of the Indian Creek Nature Center is true sustainability. As a means of measuring and verifying that the new building is truly sustainable, the ICNC is designing the new building to meet the requirements of the Living Building Challenge. As the Commissioning Agent, our work will primarily impact the net-positive energy aspect of this project - ensuring that the building produces more energy than it uses.
Why take on the Living Building Challenge?
"We wanted to drive the community – not just our local community but the entire state, the entire nation – forward, to really take a stronger look at building practices… it was intended to excite people about the future of who we are."
- John Myers, Executive Director
The Living Building Challenge "is a building certification program, advocacy tool and philosophy that defines the most advanced measure of sustainability in the built environment possible today".
- The International Living Future InstituteThe Challenge is comprised of seven performance categories called Petals: Place, Water, Energy, Health & Happiness, Materials, Equity and Beauty. Petals are subdivided into a total of twenty Imperatives, each of which focuses on a specific sphere of influence.
About the LBC
"The LBC also focuses on how people feel in the space, so we're incorporating a lot of biophilic elements and beauty that are taken from nature."
- Jean Wiedenheft, Land Stewardship Director and Amazing Space Project Manager
Meet the Team:
- Indian Creek Nature Center Project Manager: Jean Wiedenheft
- Architect: Solum Lang Architects, LLC
- Mechanical and Electrical Engineer: Design Engineers P.C.
- Civil Engineer: Schnoor Bonifazi Engineering & Surveying
- Structural Engineer: DCL Consultants, LLC
- Landscape Architect: Ruth L. Fox, Landscape Architecture and Planning
- Sustainability Consultant: Liz Christiansen, UI Director of Sustainability
- General Contractor: Ryan Companies & Rinderknecht Associates
- Energy Consultant: The Weidt Group, with Alliant Energy and MidAmerican Energy
- Exhibit Design: The 106 Group
- Commissioning Agent: SystemWorks, LLC
What will SystemWorks do?
SystemWorks will be involved in every step of the project. Beginning with Schematic Design, SystemWorks is a second set of eyes for the Indian Creek Nature Center staff. Commissioning is much more than just function testing at the end of the project. Being involved early allows us to review the building envelope details and mechanical design for constructability, maintainability, commissionability, and ensure the proposed building is poised to accept the Living Building Challenge.
Throughout construction, SystemWorks will be on-site, reviewing the installation of building envelope, mechanical, electrical, and plumbing components. We will keep this blog updated as the building progresses! For updates from the ICNC's perspective, check out their blog Here.
Think You're Net-Positive? Prove it!
Before being recognized fully as a 'Living Building', the ICNC will undergo a year-long third-party evaluation to verify the resource use/re-use and energy production/consumption.