Mounting Strategies 10.04.2010avwFm87mDz
SUNMAXX SOLAR HOT WATER SOLUTIONS
I’d like to welcome you again to another edition of our SunMaxx Solar Hot Water Solutions webinar series. Today we’re going to be talking about mounting strategies for both flat plates and evacuated tube collectors using some of the best practices that we’ve seen. And I’d also like to introduce our new set of mounting hardware solutions that I think you’ll find very effective in both structurally, but also cost.
Can anyone confirm for me please that they can hear me? Okay good. Alright, so as always you have a chat box and I welcome you to type in any questions that you have since it’s a small group with us today. I can very easily respond to your questions, try to do it immediately. So, without further ado we have just a half an hour and I try to be punctual. The new mounting hardware that is included with our collectors is really its custom designed for each job.
We designed it so that it was universal. Okay, so as you can see the same hardware used at a very large job that was recently installed in hardware with 150 flat plates, uses the same hardware in a slightly different configuration. So, what we have to offer you is a customized solution based on a universal set of materials, hardware. Alright, as you can see in the picture, the rails that were used in a harder job run from the top of the collector down to the bottom of the collectors and with smaller residential jobs, as you see in the picture photo on the right, that the rail is used horizontally, okay.
So let me go through each of these components piece by piece. It really begins with our roof penetrations; this roof hook system that we’ve developed. I think you’ll find there are similar products available, but at a much higher cost. So a couple of things I’d like to point out about this roof hook with flashing is that you don’t need to pre-drill any holes that the screws, the lag screws that are included are self tapping or self drilling screws. So, once you’re able to find the rafter, then all you’ve got to do is center your roof hook over the rafter and drill those two lag screws and those are high sheer strength lag screws, directly into the rafter itself.
We don’t recommend that you need any other waterproofing sealant. Some installers prefer to use tar or rubber with every penetration, but this is designed so you don’t need that extra barrier, okay. So, you see a flashing that’s going to slip…your gridlines represent your shingle patterns, the flashing will slip up underneath the shingle on top of your roof hook and bolts. So, the strength that comes with this system like this, I believe it can support 400 pounds of uplift and 400 pounds of down pressure as well as 120 mph winds and 180 pounds of sheer strength.
So, it’s an extremely strong roofing strategy. Now, from this main roof hook we’re gong to attach a rail. The rail, as you can see in two different depictions here, is threaded. So, you notice the Allen bolt gets threaded directly into the rod. So, what you’re seeing in the picture on your left is that roof hook gets bolted directly into the side of the rail, okay. And that can be mounted anywhere along the rail. We recommend that you don’t space those roof hooks more than 48 inches apart, okay. So, you’re not limited to the location of your rafters, really, if they’re not perfectly two or 16 inch on center, you can mount your roof hooks anywhere along that rail.
And then all you need is an Allen screw and you can connect the bolt directly to the rail. On the picture to the right is the clip that’s going to be fastened to the rail to mount, eventually, to your collector, okay. So, with the titan power plus collectors you have a threaded well that will accept your Allen bolt in that slot on the top of that clip, okay. So again, it gives you a lot of flexibility in lateral movement of your collectors and you can be symmetrical. You can line it up perfectly in the center of the roof if you like. You can move it to the left or to the right. Now, these rails come in five, seven and eight foot lengths, okay, and all of which we have in stock ready to ship.
So, I would recommend that you converse with your sales rep. Your sales rep has a software that’s going to design the components required to accomplish what it is that you’re trying to do in terms of your mounting. Now, should you need to put several rails together, we do sell two different style rail. The one on the left is the newer rail that has the threaded channel. And that union has four, all the bolts are included, it has four Allen bolts that will thread directly into the rail. And then on the right the “T” profile, this is a rendering of the “T” rail, there’s a simple clip that will secure with ridges and pinch down and fasten the two rails together, okay.
So again, regardless of your placement, we recommend that you don’t space the roof hooks more than 48 inches apart. Now for back legged frames, for if you’re going to do a tilt mount or on a flat roof, you’re going to connect the rail to the back leg using these simple clips, now again, with the stainless steel Allen bolts, will thread directly into the collector frame. Now, in terms of the feet for… Why I get a “no” from you is you’re having trouble hearing, I presume? Maybe you can work that out, try to refresh. Now, the feet will again, mount anywhere along the back leg.
So depending on, if I go backwards for a minute, depending on the length of the back leg required, all you have to do is cut the back leg to your designed length and the foot of that rail can move up the back leg to the desired, so that you can set the desired angle, okay. So as you notice, there are the threaded receptacle always goes on the outside to accept that bolt and then you install this stopper that will allow your collector to sit right in place and fasten at the bottom of the frame, okay.
Now, for flush mounts, what you see here are a total of four roof hooks with their associated flashing, and you see how the rail connects to the roof hook with the clip that I showed you before and then the collectors mount to the rail with the collector clip. Now, that collector clip has got to only be spaced the appropriate distance to meet the threaded well to accept the Allen bolt, okay. The only consideration you have to make when setting your roof hooks is the height of the collector, okay, not necessarily the distance between. So, you set your roof hooks at 48 inches and you have your height, which should be pre-determined.
Okay, can anyone else hear me? There appears to be a little difficulty, so if you wouldn’t mind just confirming if someone can still hear me. It never fails there always a bit of technical difficulty when trying to pull this off, but I think we should be all set. Okay, thanks Dennis. Alright, well, okay well, in terms of quality of audio I can make some adjustments after the fact, but now we’ll just have to run with it. So, for the flush mount you’re going two rails. You get two rails and four roof hooks with the flashing and then you mount the rails directly to the collector. It makes it very nice, clean look.
These rails are aluminum all the other hardware, the bolts are stainless steel, so there shouldn’t be any corrosion issues. The collectors, as you might remember, are also stainless steel framed so you have stainless steel mounting directly to the stainless steel. The space underneath the collectors is about only two to 2 ½ inches between the bottom of the collector and the roof. The space between the collectors is going to be about 1.5 inches, okay. So you do get, with a flush mount flat plates, you get a real nice clean look, almost like a skylight. Now, in terms of a flat roof mount, like I showed you before, you’re going to have these feet in place of the rail.
Now, there’s two ways to use the back rail. One would be using the back rail for your feet now unfortunately the location of these feet, as they move down toward the roof, do not align themselves perfectly with the rafters. So, if you would like to have that added precaution, where your collector leg is mounted to a rail rather than the roof, you’re going to use, obviously, this rail again, with a four foot roof hook spacing and then you can move your rail laterally. You can also mount these directly to the roof with other methods, for instance, and I’ll talk about them in a minute, a spanner method.
So, whereas you know, you can find your outside legs can certainly mount directly to a rafter, but then the other two legs will have to be mounted to the roof decking with a toggle bolt, with a block between the rafters or with a spanner rod that’s going to connect right up through your roof hook, okay. So, in this case you have six roof penetrations as opposed to four roof penetrations. So, going back to the rail we’ve got the same square footage of collector, but we’re using only two roof penetrations for the bottom rail and only two roof penetrations for the top. And should you decide to not use a rail you would save yourself a bit of money, probably less than $50.00 savings because you’re going to have to buy two additional roof hooks, but now you have six roof penetrations, okay.
So, you really want to try to minimize the number of roof penetrations. In the end it’s going to pay for itself. Okay, now there are several different ways to penetrate the roof, all of which should include a flashing. And the flashings can be made for asphalt shingles as well as cedar shake shingles, or ceramic tile shingles. Unfortunately, there’s no real good flashing for metal roof, but in the case of metal roofs, we use a rubber washer similar to the way the fasteners connect the roof to the rafters. The fasteners are designed to withstand the weather using the rubber washer on the top. So, we can recommend that same.
When you use this type of system, where you have a flashing, you’ve got to be sure that your flashing extends up into the shingles at least four inches, okay. So, the only recommendation is that you choose your movement, your vertical movement, the location of your point of penetration, should allow for four inches of penetration up underneath the row of shingles above it, okay. Okay, now there’s five general methods that are tried and true for connecting directly to the roof, right. These have been in practice for quite some time. A spanner method with a threaded rod, this allows you to locate your points of penetration, regardless of location of the rafter.
Okay, so the only draw back is you have to have access to the rafters, so for method number one, using a spanner will allow you to locate your point of penetration anywhere on the roof, but you have to have access to those rafters and you can simply put a block between the rafters and then drill up from the bottom, through the roof. That’s going to be your point of penetration. And rather than using a lag bolt you’ll use a threaded rod, okay. Now, in terms of a lag bolt with flashing, I’ve already spoke about that, but you do need to find the rafter, the exact location of the rafter because you’re going to want to split the rafter.
Bosch makes a very nice rafter binder and I believe the cost is somewhere around $200.00, but that’s going to give you a very nice image with the exact locations of the rafters so that you can split and so you don’t jeopardize the integrity of the rafter. Another one is the “J” bolt. “J” bolt does the same as a lag bolt would do it’s just that the “J” bolt is to the side of the rafter rather than in the center of the rafter. Now, you still need to use a rafter finder or you can have access to the rafters and drill up from the bottom. Now, in terms of using this on a metal roof, these will all work on a metal roof, and metal roof manufacturers now recommend that you do not drill through the ridges, rather that you drill through the valleys of the middle roof and you use a rubber neoprene washer between the metal roof and your metal washer on the lag bolt.
Okay, so you can in fact, use these with metal roofs, but as I mentioned, it’s very difficult to flash unless you build your roof around those. So, rather than using flashing, you’ll use a rubber washer that comes with our lag bolts, okay. So we sell separate lag bolts, they’re about 10 inches long, and they have the lag threads, wood threads, on the bottom with a double nut on the top separated by a rubber washer. So, you can fasten them directly down through the valley of your metal roofing as you would your fasteners. Greg that’s a great question. I’m not positive that the Bosch rafter finder works on metal roofs. I would have to guess that it would, although I cannot confirm that.
Okay, now moving on to give you an idea of the “J” bolt detail, the “J” bolt, like I said, you have to locate your points of penetration directly next to the rafter and you have to be able to find the rafter. You’re going to drill from the bottom up through the roof rather than drilling from the top. This allows you to insert your “J” bolt up from the bottom and in the “J”. Part of that bolt will connect it with the rafter, okay. Now, when it comes to mounting the vacuum tubes to the roof, just like the flat plates, they don’t align themselves perfectly with the rafters. The points of penetration should really align themselves with the rafters.
So, in this case its better that you use the rail system, okay. The rail will allow you to mount directly to the rafter and then if you see this photograph here, the feet of the evacuated tube collector, which are included, alright, so with a vacuum tube collector, you get the entire collector frame, some of which you may not need, but the details from the rail down will be the same for flat plates and evacuated tubes. The only difference is the connection between the vacuum tube collector and the rail will be accomplished by the feet of the collector, whereas the connection between a flat plate and the rail will be accomplished by a separate clip that comes with your mounting hardware, okay.
Now, flat plate flush mounts are probably the most aesthetically appealing. And for those of you who have been through our level one training, you do recognize and you should remember that the performance losses from a decreased angle, are really quite minimal, okay. And so it’s hard to be exact without using a specific example, but for example, we have a roof pitch here that appears to be about 30 degrees. So, these collectors are mounted at 30. Knowing the location, presumably in Upstate New York, just I recognize this install in Syracuse, the angle, the optimum angle for this installation would be 42. So, they’ve lost 12 degrees in their angle by mounting them flush. What does 12 degrees do to the loss in performance? It turns out that they should have expected loss and performance of less than 6%, okay.
And so what is the payback on that 6% in terms of aesthetics and also ease of installation? Flush mounts are much easier to install and they look much nicer, okay. So, please remember that many of your future jobs will be referral based, and most referrals, whether we like it or not, will be based on the aesthetic appeal, not only internally of the piping and tank and pump station arrangement, but also on the aesthetic appeal of the mounting, even more so because people will see those a lot more readily than they’ll see the internal guts of the system. So, please do consult with your sales rep or if you have specific questions you can email me regarding your losses and from, you know, a 30degree angle versus a 42 degree angle, would have a significant difference on aesthetic appeal.
Okay, now in terms of mounting “T” profiles to the roof, the “T” profile is another option for using the rail system. This is a more cost effective approach, but the strength of these rails and versatility of the rails are less. So, SunMaxx has decided to go with a much more universal and versatile system, but we do still offer this “T” profile as they’re very cost effective solution for flush mount systems, okay. And what you see here is a photo of our hanger bolts that are mounted directly into a rafter with a piece of flashing and you see the black rubber gasket. Okay, the “T” profile is going to mount directly to the collector.
You see the bolt being inserted into the manifold, err, I’m sorry, into the collector frame. This piece that you see on the roof here, it would be the top. And then for the bottom rail the orientation would be the opposite. So, most of the weight of that collector would mount on the bottom rail. Using the hanger bolt you can see a nice clean look. The rubber washer that you see here, in the case of a metal roof, would sit directly on that metal flashing or directly on the roof, okay. And these little clips secure the “T” rail to the hanger bolt. So, the amount of installation time required for this new system and the difference between the “T” rail is minimal. Both the roof hooks and the hanger bolt option is going to take you, honestly less than two minutes per penetration.
Okay, so once you find the rafters, the penetration is securing the roof hook or the hanger bolt is less than two minutes. So, it’s quite easy to do. I want to point out a couple of variations in collector mounting, especially for the vacuum tubes; you can see a high degree of reflectivity is going to increase the performance upwards of ten to fifteen percent. And I’ve even seen collectors that are performing 20% more than what we would anticipate because of that reflectivity, okay. With a flush mount system reflectivity is very easy. You can simply paint the roof. One thing that we discourage is by adding too much behind the collector on a tilt mount because you’ll increase the wind load.
Okay, SunMaxx has decided that the value in reflectivity, by including a reflective surface on the collector itself, reflectivity does decrease dramatically. And so you’re better by increasing the reflectivity of the roof rather than increasing the reflectivity by adding a structure to the collector because you do add a significant amount of wind load. Sherwin Williams, for example, makes a highly reflective roof paint that is sold at $30.00 a gallon and you can simply paint your roof as this photo on the top portrays here. With those three collector in series the roof has been updated to become highly reflective.
Another consideration is mounting these collectors miscellaneous in moveable array, although in theory, may provide an added benefit by decreasing the production in the summer and increasing it in the winter, which is what you’d like to see for systems. It takes a very, very special design and in some cases may not be worth the cost because as you know, angle of inclination there’s a high degree, about a 30 degree window before you begin to suffer any serious losses. When mounting this system on a ridge, as you see here, will increase the performance because if the house if oriented from north to south with the ridge line, then your options, other than doing it on a ridge would be to face the collectors to the east or facing the collectors to the west.
And again, if the house is oriented magnetically north and south, that doesn’t necessarily mean that you’re going to be that far off when you compensate for the magnetic declamation. So, you might not lose as much as you think by mounting them to the east or to the west. Richard, we don’t have a solution for ridge mount systems. A lot of it is going to be custom design. Now, I can tell you this, the hardware that is included with both the flat plates and the vacuum tubes, is universal and fully adjustable. So, with the additional purchase of a few extra rails and clips they can all be interconnected so that you can custom design a ridge mount.
I will probably not recommend the ridge mount for flat plate collectors due to the significant wind load that would be involved there, okay. This is some examples of ground mount systems. Alright, the hardware that is included with the vacuum heat pipes, can be fully adjustable for ridge mount for ground mount. So, you notice the back legs are used to cantilever the bottom off. Okay, again, there’s very little wind load. So the frame that’s used to hold these collectors up really just needs to be designed to support the weight, okay. And the weight is only about 7 pounds per square foot, 5 pounds per square foot for flat plates.
Flat roof installs with vacuum tubes are very easy to do. In this case we have very low wind load. So, these collectors are simply mounted or ballasted onto the roof with concrete pads, little concrete pavers to be exact and tapcons that are screwed. So, there’s no roof penetration. So, this is a gravel roof and basically the collectors are setting on the gravel roof with no penetrations at all. In the case… You have a little bit of shading. So, collectors can be used on apartment garages for shading. Richard, all of our mounting hardware is up to U.S. building code standards. So they are suitable for engineer stamps.
Every piece that we use in our system has ratings that exceed required values. So, you could very easily get the engineered stamp with the hardware that’s included. Okay, and here’s another example of ridge mount rather than mounting it transverse along the ridge, it’s mounted parallel with the ridge, but the back legs are on the north face of the ridge and the front legs are on the south face of the ridge. Okay, this allows you to get a steep angle and disperse the weight of collector back on to both sides of the ridge. Again, you can do this effectively with vacuum heat pipes because of their low wind load.
Okay, another example flat roof installs we do recommend that you bring the collectors up off the roof a minimum of one foot. No, I really don’t have anything at this point for awning mounts, although if Richard, if you email me I can give you a couple of examples. Okay, so we recommend that you bring your collectors up off the roof a minimum of 12 inches to get them out of the snow if you’re in snowy climates. And if you’re not in snowy climates then congratulations to you, although you probably do miss, or you would miss the snow, I think I would for all of its drawbacks. Okay, you can always increase performance easily with vacuum tubes as I mentioned by increasing the reflectivity and also by allowing any of that diffused radiation to strike the collectors on the back.
Pole mounts are also a very good solution and… Okay, good thanks Richard. Pole mounts in some cases might be cost prohibitive. The photo on the left probably cost a considerable amount of money to get that south facing slope whereas if they had mounted on the east or the west they might not have lost as much as they think. In this case the collector, that single collector unit, is supported by a pole that houses the supply and the return. Concrete standoffs can be used on ground mount or roof mount. The picture on the left shows the concrete standoff being used on a gravel roof. And this is the Wallkill Prison job that has recently been completed, which is 18 inches up off the ground.
Okay, and these are glued together. And then you fasten the feet or fasten to the concrete directly. I’d also like to point out summertime production can be decreased by mounting vacuum direct flow vertically, which gives you a lot of wintertime gain and then the photo with this installation where the gentleman built a roof so that both his rows of collectors are getting the wintertime gain, but the bottom row loses the summertime production because of the high angle of the sun. Ground mounts are easy to work with. If you decide to go with a ground mount you will have an easier time at washing your collectors, maintaining your collectors and also covering your collectors should you experience overheating system.
Okay, drain backs to remind you, need to be mounted at a ¼ inch a tilt per foot. Both are flat plate titan power plus. And our vacuum tubes are suitable for drain back. Okay, in this case we have a rail mount using hanger bolts and the threaded rods; the double nut system is just used to create that angle on both the front and the back. Okay, to wrap it up a couple of important considerations that I want you to remember, that the universal mounting hardware is designed for any type of roof, not just any type of roof, but you can use them with any of our collectors, flush mount, tilt mount, flat roof mount, ground mount, ridge mount.
It’s designed to be very customizable. And when you do decide to place an order with your sales rep be sure you know how you’d like to mount these collectors so they can very easily customize your mounting solution. Also, to remind you that our hardware does meet all the U.S. building codes, so you will be able to get engineered stamps with the use of our system. And not to preach to the choir, ‘cause I’m sure you know this, but it’s very important that you make every precaution to be sure there’s not going to be any water penetrations on your roof, okay. Your system will speak for itself and in performance and so will the lack of phone calls for service speak at your ability to install a system.
So, please do make precautions that you don’t get a phone call during a rainy storm in the middle of the night. And also, know your local building codes. Your sales rep can forward to you our technical data sheets for all of our collectors that will include the information that might be required. Some building codes do require a very significant amount of detail for every single component and some don’t. So, you have to look at your own building codes. Okay, now, with that I’d like to thank you for joining us for this short discussion on mounting strategies. I welcome you to continue to join us. Hopefully you were able to pick up on some information. Stay tuned for next weeks solar webinar series and give us feedback, if you have any. I wish you all a great day and I thank you for your attention.