Drainback Solar Heating System

There are two types of solar heating systems appropriate for cold climates: glycol and drainback closed-loop systems. We chose to use the drainback system because it best fit our application. Rather than explain this system myself, I think this is the best internet site to begin learning the details involved in it. Our system is essentially designed on the same principals found at this site. However, our system only has one tank, which acts as both the drainback tank and the storage tank.

The article found at the referenced link explains that a drainback solar water heater is not able to provide 100% of the hot water we will need. So we have paired our system with a tankless heater. This will provide any additional heat we may need on the coldest and cloudiest days in Torrey.

This is the mechanical room for both the culinary water and the radiant floor. Heat for both will be provided by the drainback solar heating system. The tankless heater that provides any necessary supplemental heat is the gray box in the upper right hand corner of this photo.




For us, the negative aspect of this whole system was the type of solar panels we could use. As you can see, they are big and architecturally unattractive. The fact that we will ultimately use minimal propane for heat resulting in very small utility bills, will make them more and more attractive as time goes by. With a closed-loop glycol system, it is possible to use panels that can be mounted flush with a roof, but the glycol system appeared unworkable for what we needed.

I did have to laugh a little when reading one internet site that said, "... the drainback solar system is relatively cheap and simple to install and maintain." I'm just not quite sure what it's cheap relative to.

Solar Heating System

It’s funny how ostensibly minor events are, in truth, milestones. Today that small event was a drive to the post office to mail an envelope containing the documentation showing our solar heating system is now installed and working. It’s the details that led to this moment that paint the larger picture.

Detail number one: In early May of 2010, Wayne, our architect, visited us in Torrey for a few days in order to help us work on our timber frame. Serendipitously, during that week, Phillip, our plumber stopped by our yurt to discuss the installation of the water tank for our solar heating system. Because they both happened to be there at the same time, they sat down together and devised a much-improved plan that would store our hot water in an underground tank and would preserve storage space inside our house.

Detail number two: Not long after, Dura Crete, a Salt Lake company, manufactured that water tank and delivered it to Torrey where it was easily installed in a hole beside our house. On the same day, Phillip and company completed that portion of the solar heating system by, among other things, placing copper heat exchangers inside the tank.

Detail number three: At the same time, Scott, Doug, Shanna and I laid out the PEX tubing which will allow the hot water from the buried tank to circulate throughout the house providing heat when we need it. Once that was done, Tyler and crew poured our cement floor.

Detail number four: In August, we raised the timber frame and built the porch in September and October.

Detail number five: Tyler’s crews spent any time they had between jobs from October to the first week of January building the roof to the point when Scott would be able to blow in 10,000 pounds of insulation, which he did from January 11-14.

Detail number six: The weather was cooperative so, once again, Tyler and crews ? into action and put the exterior metal sheathing on the entire house (except the porch) and installed the tubular skylight  in the main bathroom.

Detail number seven: With the weather still cooperating, Phillip and Paul had the perfect window to put our six solar panels on the roof and complete the entire heating system.

Detail number eight: Scott and I drove to Torrey last Friday, met will Phillip to gather signatures, and we took photos of the entire heating system in order to provide the required documentation for our Utah Renewable Energy Rebate...due on March 7.

Detail number nine: Scott spent two days preparing the final paperwork for the rebate and put the whole affair in the mail this morning.

Why a milestone? We’ve made the deadline with time to spare. But even more importantly, Scott is scheduled for back surgery on February 28. We’ll take a hiatus until he’s back in building shape, and we have no looming deadlines to meet. Whew!

Phillip and Paul working on the copper heat exchangers.

Scott down the access hole to the control "room" of our water tank.

Scott receiving instruction from Phillip.

Six solar panels on the roof.

 Scott stroking the panels.

Scott, Phillip and the panels.










Insulated pipes bring water from the panels to the tank and back.

Phillip teaching Scott how the system is regulated from the mechanical closet.

The panels at work bringing the water up to a perfect 140 degrees.

More on Windows and a Bit on DIY

Since we are trying to save money by doing as much of our own construction as possible, it means we absolutely must pay attention to details. Yes, we have subcontracted out many things: cement work, plumbing, electrical and much of the roof. But I guess we are considered our own general contractors because many of the big decisions and much of the precision are, generally, left to us.  Making these choices and ordering the correct items in terms of type and size requires a great deal of research, and this is one of Scott’s fortes. Our windows are a prime example.

As mentioned earlier, our plans called for Loewen Windows, but Scott’s research convinced us to purchase Serious Windows. When ordering windows, three factors come into play: U-factor, Solar Heat Gain Coefficient (SHGC) and Visible Transmittance (VT).

According to The Efficient Windows Collaborative, U-Factor is the rate of heat loss of a window. The lower the U-factor, the greater a window's resistance to heat flow, hence, a better insulating property. (This is similar to the R-Value in walls and roofs.) High-performance windows have a U-Factor of .30 or lower. All of our windows with the exception of the three pictures windows on the south side of the house have a U-Factor of .18. The pictures windows have a U-Factor of .23.

The Solar Heat Gain Coefficient or SHGC is the amount of solar radiation that passes through the window and heats the house. SHGC is indicated with a number between 0 and 1. The lower a window's SHGC, the less heat is admitted into the house. Except for the picture windows, all of our windows have a SHGC of .21. On the south side of the main living space of our house, the eaves will prevent sunlight from shining directly into the house in the summer. However, they are designed to allow sunlight to enter the house in the winter in order to heat the house. Therefore, the SHGC of the picture windows is higher —.50. This higher SHGC also means that heat will escape at night. To prevent this from happening, we'll use insulating curtains on these windows in the winter.

Visible Transmittance (VT) is the amount of visible light that comes through a window. Most VT values are between .30 and .70. Higher VT values maximize daylight and view. The VT on all windows except the picture windows is .4. Since our view is to the south, the picture windows have a VT of .64. More light to see our world.

Just like good glass, it’s amazing what a lot of research will reveal.

Serious About Windows

From the very beginning, Scott and I understood there would be three (at least) big-ticket items for the house: the roof, the solar heating system and windows. As the roof and the solar heating system near completion, it is time to turn our attention to the windows.

We actually began investigating windows even before Wayne had drawn up our blueprints. Early in the planning stages, Wayne took us to the Loewen Windows show room in Salt Lake. Loewen is the brand Wayne has in his straw bale house in Idaho. According to the literature, Loewen windows have extremely high thermal performance which has led to their Energy Star designation. And, as we saw in Wayne’s house, the douglas fir casing and brick mould are absolutely beautiful. As you can guess, they also have a price tag to match.

Still, we had agreed to spend what was necessary to have excellent windows. After all, since our walls have an R-value of 40 +, we better have high-performing windows to fill the holes we make in those walls. We were planning to go with Loewen window until two things happened. One - I asked my mom how she liked her wood windows. She said, if she were to do it over, she would NOT have wood because they require so much maintenance. And two - we learned about Serious Windows because Scott, always one for extensive research, learned they were the most efficient windows available.

Plus, get this, the EMPIRE STATE BUILDING, in a retrofitting project, will be using Serious Windows. Hey! If they’re good enough for the Empire State Building, they are good enough for us. And we won’t even have to worry about cleaning glass 1,250 feet off the ground.

Yes, there is a big price tag for their performance, but we’re excited to have such a great product in our house. Last week, I took a big gulp and wrote the check. The windows should be delivered this summer!

Ten Thousand Pounds of Insulation

Whenever we pick up a magazine these days, it’s common to see articles entitled “Seven Steps to a Green Home,” “Affordable Solar Energy” or “Create the Perfect Home with Alternative Building Systems.” We get a little chuckle when we read those articles because we continue to be reminded that those seven steps are not necessarily simple or affordable, and the definition of “perfect” encompasses a range as broad as the Rockies. However, when it came time to insulate the roof of our house, the nexus of simplicity, affordability and perfection seemed to land very neatly on our doorstep.

When we left the house in November, 16-inch scissor trusses had been set in place on top of the interior sheathing. Off and on throughout December, subcontractor Kirk Chappel and his employee, Brian Briel, added the exterior roof sheathing and built the east and west gable end walls. Our next task was to fill the cavity between the interior and exterior roof sheathing with insulation.

Wayne, our architect, designed an unvented roof that would have an approximate r-value of 60. To achieve this, we would use cellulose insulation purchased from Mountain Fiber Insulation in Hyrum, Utah. You might ask why we would bring insulation all the way from Cache Valley to Torrey when we could have, perhaps more easily, purchased it from Loa Builders. That is a fair question especially considering our determination to use local products and employ local people.

For us, there are two "locals." We chose to work with this Cache Valley business because the product is made from 100% recycled paper, it fit our needs exactly, we know the owners personally, they allowed us to use their heavy-duty equipment free of charge and they gave us a great deal.

Scott arrived in Torrey on January 11, one day prior to the semitruck delivery of 484 bales of insulation. With the help of Kirk and Brian, in less than four days, that insulation had disappeared inside our roof, and Scott was back in Logan the following Sunday. Here’s what happened, step by step.

This is our roof as we left it last November. Notice the 16-inch scissor trusses. The insulation will be blown between and across the trusses.

Here, on January 11, it looks like the roof is essential done, but the space between the interior and exterior sheathing is empty. In must be filled with insulation.

The insulation begins its life as 100% recycled paper - the crossword puzzles, comics, magazines and phone books we throw away every day.



 

This machine shreds, grinds and pulverizes the paper...

into cellulose insulation that is then treated with 100% borate fire retardant that also provides fungicide protection.

Using the Mountain Fiber equipment, the contents of 398 bales (almost 10,000 pounds) is blown into the roof cavity at a density that is so compact, it will not settle...hence an r-value of 60.

When Scott left Torrey, he brought 86 unused bales of insulation and the machine with him. It was covered with the tarp because it began to rain on the way back to Logan. We were lucky. The rain held off while Scott was working. The weather gods smiled upon us one more time.

Next week, Tyler Torgerson and his crew will install RMax Thermasheath as the next layer on the roof. This is a rigid foam plastic thermal insulation board composed of closed cell, polyisocyanurate foam which is bonded to reinforced aluminum foil facers. Our ASC standing seam metal goes next. Then, and finally, Phillip Winters will be able to install our solar heat exchange panels...all just in time to meet the deadline for our alternative energy grant.

Our Front Yard

North, south, east or west, the view from our porch is beautiful enough to make your heart stop. It's a wonder we get anything done at all when all we want to do is look and look and look. All of the photos in this movie were taken from the front door of the yurt or from the house construction site.

The State of Things

We left Torrey to return to Logan at 11:15 on Saturday, November 13. Stegner, Arion and Charlie (our llama family) peered out the windows of the trailer not happy about spending the next six and half hours in such close proximity to each other. The paraphernalia of Torrey life was crammed into every available crevice and gap of the truck.

Dave at the saw

Tyse on porch decking

As we pulled away, Dave and Tyse were finishing the last of the decking on the porch roof. There was nothing more Scott and I could do for the moment and Logan obligations called from the north.

Reviewing the progress of this second building season, we have...

* put a wood-burning stove in the yurt
* planted and fenced 20 trees - 10 cottonwoods, 1 Fat Albert blue spruce, 5 blue spruce seedlings, 2 apple trees, 1 plum tree, 1 cherry tree
* installed the PEX for the entire floor
* poured the concrete floor in the bedroom, office, kitchen and master bathroom
* laid the first five inches of the earthen floor (the last one inch to be installed later)
* insulated the foundation with Pink Panther rigid foam
* mortared slate to the entire exterior of the foundation
* built a sill plate for the straw bale walls
* buried the 21,000 pound water storage tank for the solar water heating system
* graded the building site to eliminate piles of dirt and fill in holes
* finished and raised all of the timber frame (HOORAY!!!)
* assembled the core of the Tempcast masonry heater
* purchased and stacked 500 bales of straw in the garage and to the north of the garage
* cut, sanded and sealed all of the porch posts, rafters and beams
* erected the porch
* framed the interior walls
* selected and purchased almost all of the lights for the interior and exterior of the house (This had to be done in order for the electrician to wire the house.)

Solar Mechanical "Room"

Trent Hunt has placed all of the electrical wires above the ceiling. Phillip Winters has completed as much of the solar heating and water system as is possible without a finished roof. Tyler Torgerson and crews have completed the decking for the entire ceiling and porch plus added the waterproof felt layer and the metal drip edge.

While we work here in Logan, Tyler and crew will continue working. Eventually the phone will ring, and we’ll head back to Torrey to blow the insulation into the roof.

For now, Scott and I have called a hiatus. We know the first, middle, last and nick names of every piece of wood in our entire house. Our sweat, tears and not just a little blood linger everywhere. There is still so much to be done. Maybe we can complete our 2010 "to-do list" before the 2011 season begins.

November 2010

November 2009