Twinsprings Research Institute

Spring Break!

Posted on March 28, 2015 by ellen

We took another couple of days off to do some lakeside camping for part of the grandkids spring break. It snowed the day we were going to leave and I had a training for Rocky Mountain Green volunteers so we only spent two nights. Our grandson had a pretty bad cold, but we still had a great time. We played about 80 games of Uno and somehow our grandson always evened the score. We played in the little bit of sand by the lake and we played with the kids from the next door campsite.

Playing at Carter Lake

The RV made the nights in the high 40’s very comfortable and the daytime temperatures were in the 70’s. Lovely place. Lovely time.

RV at the lakeside camp site.

Posted in Diversions | Comments Off

The Windows are Coming!

Posted on March 28, 2015 by ellen

We have a ship date on our Alpen order of windows and doors! They are due Monday the 30th of March. That is just a week later than the original estimate. The installers are set to start on April 1st. Happy April Fools!

So we are getting ready by removing the trim from the rear windows as well as those in the slab part of the house. We also had to dig out the retaining walls for the north bedroom egress window. That one had some pretty bad rot on one corner where the wood sill was in contact with the ground.

Leaning retaining walls

Removed top part of walls

The window is now fully accessible from both inside and outside–hopefully the replacement will go smoothly.

We also removed the trombe walls at the front of the house. Most of the trim was held on by screws and it was a reasonably simple job to removed the screws and gently remove the glass. One piece of glass under the window in this photo was gone when we bought the house. Now we have to find out how best to reapply the glass and seal it to create a better trombe wall. This is an old photo from 2012 when we were removing a tree that shaded the wall.

Trombe wall

Posted in Air Intrusion/Thermal Envelope, Energy Efficiency | Comments Off

Ill fitting LED’s

Posted on March 24, 2015 by ellen

Unfortunately, the G25 Globe bulbs did not fit the Prescolite track heads. The necks are too short to fit into the sockets because of the lamp collars. Actually I read this caution on an Amazon comment but ignored it thinking the track heads were not as deep as some can lights. No dice.
But I will keep the G25’s as they look great in other lamps. The warm light is much brighter than the CFL it replaced which was supposed to be equal to a 60 watt light.
So I ordered these Feit R20’s too. From Ebay I could get 10 with free shipping for $69. That is still reasonable for the high CRI bulbs. They still use 8 watts but have fewer lumens so are not quite as efficient as the G25’s. (450/8 = 56.25 lumens per watt) I didn’t want to use a full 12 watts for each bulb so bought the R20 size (20 1/8″ increments or 2.5 inches wide) instead of the BR30 (30 1/8″ increments or 3.5 inches wide). I hope they fit!

Feit R20

I also found that I could get the R scores–that is the degree of Red in the light’s spectrum from the Energy Star list of certified lightbulbs. Download the Excel file to get them all. Not all bulbs list the score but most of the higher CRI bulbs do. These Feit bulbs have an R value of 62. The GE Reveal have an R value of 90 (out of 100). It is by far the best color rendering bulb, however it does that at the cost of efficiency and it is usually more expensive.

More information from Flexfire LED’s–What is CRI?

“Testing for CRI requires special machinery designed specifically for this purpose. During this test, a lamp is shone onto eight different colors (or “R values”), termed R1 through R8. The lamp receives a score from 0-100 for each color, based on how natural the color is rendered in comparison with how the color looks under a “perfect” or “reference” light source at the same color temperature as the lamp (i.e. natural sunlight at 5,600k, or a candle at 1,850k). The lamp’s eight scores are then averaged to determine its official CRI. ”

Notice that the temperature at which the light is tested can also influence the apparent colors in that light. So daylight bulbs at high CRI/R values are tested at 5000k which would make their color rendering closer to “sunlight” vs. 2700k lights which are “warmer” and would simulate color rendering closer to candlelight.

The bulbs came and I installed about half in the 7 LED line. In the photo the rear three are LEDs, the front three are incandescent. Looking at the bulbs from each direction, it is difficult to tell any difference at all between the 60 watt incandescent and the 45 watt equivalent Feit bulbs. Except knowing the cost of the new bulbs is about 12 times more.

LED and Incadescent Bulbs

Over the life of the bulb–25,000 hours vs. about 1000 hours of use? (Or at 12 hours per day, about 6 years vs. 1/4 year–longer estimates of life are usually based on about 3 hours per day.) There are plenty of websites that show a calculation of the “comparative cost” based on lumen output over the projected life or based on the cost of projected electricity use. But over the course of several years, neither the cost of electricity nor the lumen output of LED’s is constant so the costs are relative.

As other bulbs take over the market, incandescent bulbs have gotten much cheaper too so today’s comparison is brief to be sure. Anyway, I don’t like arguments that say electricity is a trade-0ff with cost. Up to a point, the cost of energy saving measures like these LED’s is a small price to pay to use less–just like buying a hybrid car is a comparatively small price to pay to use less fossil fuel in gasoline. We are also buying new engineering, which is more expensive than using older technologies too. And that fits us all better!

Posted in Electrical, Energy Efficiency | Comments Off

LED Bulbs

Posted on March 21, 2015 by ellen

LED bulbs

Using 7 incandescent 60 watt bulbs in the new track lighting requires 420 watts of electricity. My son-in-law has been experimenting with LED bulbs and has found some he likes and I observed the bad ones he had to return too. These expensive bulbs are about $10 each from Ace Hardware and Amazon but they cut the electricity use to 12 watts instead of 65 for his bulbs.

I could use his experience to purchase LED bulbs for the track lighting. But I still spent a full day researching and trying to find the best bulb. First I had to learn a lot more about LED lighting. Even though the Cree bulbs are highly regarded in reviews, Rob prefers Feit or G7. He has also tried Triangle and does not like them as well. He also prefers a whiter light at about 3000k and I liked those too so I decided to look for a similar bulb for the track lighting. It was not that easy.

Once I started learning more about LED light, I found criteria I had not known existed. Besides the color temperature which is warm at about 2700k and cold or daylight white at 5000k, there is a color rendering index that has gotten a lot of attention, especially because fluorescent and CFL’s leave out so much of the spectrum that incandescent bulbs got us used to. LED lights were typically around 80 CRI, but newer LED’s are in the 90’s with a typical incandescent at 100. Bulbs are tested to show how much of the color spectrum they reveal. So GE Reveal bulbs are fantastic as shown by the chart below. Most bulbs just about eliminate the red tones.

CRI Color Chart

The lumen rating is the brightness or the amount of light that the bulb provides and the wattage is the use of electricity to provide that light. Divide the lumens by the wattage to get lumens per watt, which is the measure of efficiency. And finally cost is an issue with these expensive bulbs. Most are around $10-$15 per bulb although you can find some brands on ebay for less and the “smart’ controllable bulbs are twice as much. In packs they can be less expensive per bulb too and I needed at least 7 for the track we installed.

After some research on CRI, I thought a 3000k bulb with one of the higher CRI ratings would be perfect. But such a creature was not to be found. I could find some 5000k bulbs with lower CRI ratings and 2700k with higher CRI but very little was available in 3000k. Many of the 5000k bulbs were reviewed as casting a “blue” light–I bought some of the earliest LED bulbs years ago and they were completely blue so I shied away from 5000k. The Feit round G25 caught my eye on Amazon because it comes in packs of 3 and was 3000k. It is rated equivalent to 40 watts but had 500 lumens at 8 watts. But the CRI was only 80. Feit has introduced an enhanced G25 that shines 495 lumens at 8 watts but is 2700k which is also in packs of three. Weighing one characteristic against another, I decided to buy the higher CRI rating.

Feit G25 CRI

These bulbs are dimmable too. I don’t currently have a dimmer but if they are going to last the full 20 years, (25,000 hours) it seems we might want bulbs that are dimmable during that time so I wasn’t considering any of the non-dimmable bulbs. On the other hand a CNET review of the 60 watt replacement Feit bulb showed terrible flickering on a dimmer, yet my son-in-law’s flood lights don’t flicker on his dimmer.

I considered the 65 watt BR30 flood light from Feit with the enhanced CRI rating, but the efficiency for 750 lumens @ 13 watts was 57.7 lumens per watt, which is pretty low. I could buy these flood lights on ebay for less than the $10.25 in packs of two on Amazon or about $7.50 per bulb, but these were also only 2700k in color temperature. The G25’s use only 8 watts for 495 lumens or 61.875 lumens per watt. Unfortunately these high CRI 94 bulbs are also only 2700k. So for cost reasons, I ordered three packages of the G25’s for $55 because there was a percentage off for multiple packages too. That was the least total expense for the most efficient lumens at the highest CRI that I could find.

Other bulbs that I considered were high CRI too. The GE Reveal was rated one of the 5 best for 2014 by CNET and I could get 8 on ebay for about $12 a bulb, but the watts per lumen is only 50 and the color temp is 2700k too. Also the TCP Elite has a 93 CRI and is 2700k, at 650 lumens, it is rated at 12 watts for about 54 lumens per watt.

GE Reveal BR30

TCP Elite

Another cool bulb is the Insteon. For $30 a bulb, it seemed extravagant to buy a bulb that could be controlled by Zwave wireless. Turning bulbs on and off from my iphone is not something I want to pay 3 times more for–yet. But the 60 watt replacement bulb is 8 watts for 591 lumens for 73.875 watts per lumen and a color temp of only 2400 and the CRI is more typical of most LED’s at 82. (TCP Connected is a slightly less expensive programmable “smart bulb”.)

Other lower CRI bulbs that I looked at were the Great Eagle 7 watt BR20 (a smaller flood style) that had the desired 3000k color temperature but only 80 CRI for about $12 each. At 500 lumen they were 72 lumens per watt which is more efficient than the Feit bulbs. The Phillips Slimstyle had an interesting shape. The 5000k lights @ 650 lumens were on sale at Home Depot for $11. CRI is 81 and at 9.5 watts they rated at 68.4 lumens per watt.

Insteon

Great Eagle BR20

Phillips Slimstyle

Delivery of the bulbs is next week! We also expect the windows and doors sometime next week and it is Spring Break so we will have some time with the grandkids. Very exciting.

Posted in Electrical, Energy Efficiency | Comments Off

Track Lighting

Posted on March 20, 2015 by ellen

We noticed that our living area is very dark at night. This could just be the contrast with how light it is during the day, or it is because the clerestory is so high that light gets lost in the large space. A table lamp and even a clamp on lamp seemed to get swallowed up with darkness.

So knowing we needed more light above, I noticed some track light for sale on Craigslist in Westminster–one town over. It was on the site for a long time for a price that I didn’t want to spend on used lighting, but I decided to email an offer after several weeks and it was accepted! The lighting had been used in a conference room and came with 48 heads and 24 “full size” 44″ tracks with 8 shorter ~30″ tracks. Each track had a flexible connector attached and there were several end pieces on the shorter tracks.

The system came with one power head but the cap was missing so after unpacking, I realized I would want to add some components. The system was made by Prescolite which is now owned by Hubbell Lighting. The site has tons of information about their lighting systems and the track system I purchased seems to have evolved into the Architrak line. The heads are similar to these:

Architrak Head

And the track is the nominal 48″ length–or would be with a power head added to the 44″ basic track.

Architrak

The track can carry two circuits if a two circuit head is installed but most heads are single circuit and that is all we need for each string of lights.

Most sites will tell you that you have to buy all components from one manufacturer for them to work together but that is an exaggeration. There are actually some third party systems that say they are compatible with certain other systems and Prescolite publishes a compatibility chart for their system.

Compatible track adapters

I scoured ebay for new Prescolite adaptors and power heads but I found the prices rather high. Then I thought of using a compatible brand but I was seeing several that didn’t match those in the chart so I did more research about track compatibility.
Turns out there are basically three types of standard tracks (not including all in one systems that are popular now.)

H-J-L Tracks

Types of Track

Both Juno and Prescolite are J track systems. And Juno connectors were easier and cheaper to purchase. I found a power head for an electrical box on Amazon and short connectors (as opposed to the long flexible connectors that came with the track) and another power head for conduit at Home Depot online–so I had to wait for them to be delivered. But this week the track lights went up in the living room/kitchen! We used 1 power head, 6 full size tracks and 2 shorter tracks. I put up 7 heads after looking at some lighting design information. To get started I just used some incandescent bulbs we had on hand–since we stopped using them for most of our lighting some time ago. It is quite a bit brighter in the room when these are on!

Track Lights

Posted in Design Style, Electrical, Reduce Reuse Recycle | Comments Off

Unrealistic Expectations for HERS Score?

Posted on March 20, 2015 by ellen

HERS Index-Energy Star

One of the first steps in aspiring to a LEED certification is to project the number of points that could be accomplished during the building so that choices can be made to provide the best energy efficiency possible.

During the preliminary rating we targeted a HERS index score of 40. That is considered a “great’ rating, however a zero is a net zero energy use house. 100 is a typical house built to 2006 energy code standards and 150 is the highest score for a house that uses 50% more energy than energy code standards for its size.

The Energy Logic folks just completed the preliminary modeling for our HERS index and they are projecting a score in the 60’s. That was a huge disappointment as it means far fewer points towards our LEED rating than a 40. So I wondered if I had set up an unrealistic expectation for the work we are doing to the house.

The HERS score is based on the energy that a house will use compared to a “reference house”. The reference house that the building is compared to is the same size and configuration as the house being evaluated–as built to the 2006 Energy Code which gives a rating to the house of 100. Then the BTU’s of energy projected to be used in the house based on the energy efficient improvements are figured and divided by the BTU’s that the reference house would use. The result is the percentage improvement over the reference house–or the HERS score. As noted in the diagram, an Energy Star home would be expected to score about 85.

So where did we get a target of 40? The HERS rating diagram calls 60 “GOOD” and 40 “GREAT”–so we thought a house specifically designed and upgraded to be very air tight and energy efficient, supplemented by passive solar heat and high efficiency appliances would be “GREAT”! That may have been unrealistic.

Energy Logic’s Adam Jonash told me that the lowest HERS they see without adding produced energy to the equation is in the 50’s. That seems to be confirmed from other sources. Energy Star 3 would score about 70-75. And 45-50 is about as efficient as possible without adding renewable energy.

HERS Expectations

On the other hand, this is what a Passive House score might look like–they generally don’t add photovoltaics and/or wind but rely on heavy walls and tight construction.

Passive House HERS Rating Level

And a typical LEED certified home has a score between 40 and 70. But some of those might have produced energy added to the equation but they may have a lower certification level than our goal of Platinum too.

Typical LEED HERS Rating

Our bills have averaged $70 for the last year–between about $30 and $200. According to this chart our HERS would be about 50 without even finishing the house. This is based on a 2250 square foot house and ours is 2213.

HERS Index as MPG

Since our house is passive solar, perhaps the added heat from the sun could be quantified to offset our HERS score. RESNET doesn’t count passive solar as renewables though. Otherwise we could start thinking about adding solar, photovoltaic and/or hydrothermal to lower the score. The difference between 40 and 60 HERS rating is 7 LEED points. We are trying to break 100, but 94 will give us Platinum, the highest rating, so 7 points is a big part of the total.

Posted in Energy Efficiency, LEED Project | Comments Off

Original Plans!!!

Posted on March 14, 2015 by ellen

I have had the good fortune to become friends with the original owner of the house. Of course she is a very interesting person as well as a retired business owner, a wonderful gardener, and a good cook! She was kind enough to search up and down for the original plans for the home and I am fascinated by them.

The house was designed by an architect in Boulder who later moved to the northwest. Her husband was involved with a local interest group that met at SERI in Golden (Solar Energy Research Institute–the forerunner of NREL–National Renewable Energy Laboratory). The influence of the latest passive solar building techniques in the early 80’s is evident in the home–3 faces buried and the south face designed to collect as much solar heat as possible. We were reading about the same techniques about the same time but the Buffaloes were at the forefront of the movement.

There are two plans that she found–of what looks to be three original drawings. The plot plan has the topography of the lot as well as quite a bit of detail for the drainage, water and septic systems.

Plot Drawing A-1

There actually are two large septic fields, probably due to the clay soil. They lay horizontally across the elevation instead of vertically and there is a diversion valve to change which field is used–the Buffaloes changed about twice a year.

The deviations from the original plans are also quite interesting to me. The east foundation for the wall that is not buried was to be protected by a planter that never was installed. Instead there was a small deck and a hot tub on that side of the house. The hot water solar collectors behind the utility room were never installed. Probably because the home was so efficient that the extra expense and maintenance was not worth the trouble at the time.

Improvements were also made over the years. The original drive was gravel and asphalt was laid, there seemed to have been no concrete pads in front of the garage or as walkways, and of course the front yard was not enclosed by a wall and trellis that privatizes the space and allows for outdoor living. That space was designed later.

The floor plan has some of the same differences which I find very interesting. But there is also a great deal of building detail that is not currently visible–especially the construction of the trombe wall.

Floor Plan A-3

I can see that some changes were made to open the living area, but there was to be an air lock entry at the front door that was not built–instead there was an insulated 6″ wall between the master bedroom and the front hall area and a built in cabinet was used instead of a wall between the entry and the living area. Since most of the entry to the home would have been through the “back door” near the garage, the airlock at the front door doesn’t seem as necessary. But then there should not have been a need for the 6″ wall. Not sure if the builder didn’t actually understand all of the principles or if the wall was already built when the changes were made.

This plan is very much as it was built, however, the kitchen was later remodeled to have a cooking island in the middle instead of the pantry space.

Here is our latest plan for the remodel–changes were just approved by the Arvada building department for french doors in the front instead of windows and although they really don’t require strict adherence to interior layouts, the new layouts for the master bathroom and the hallway were included.

Floor plan revision 3-11-15

Although necessarily small, side by side, the plans show the differences between the original and the remodel. Clicking on any photo enlarges it individually.

Original Floor plan

Floor plan revision 3-11-15

Posted in Design Style | Comments Off

RecoupAerator

Posted on March 9, 2015 by ellen

LEED recommends an HRV or ERV mechanical ventilation and air purification system to provide adequate ventilation and air quality in a super tight structure. AE Building Systems also carries one of the most energy efficient Energy Recovery Ventilators (ERV). The ERV tempers the incoming ventilated air by crossing it with the outgoing home air. Heat Recovery Ventilators (HRV) work about the same way, except they don’t transfer humidity from the exchanged air. The RecouperAerator, made by Ultimate Air in Ohio is both an air filtration system with a high MERV rating and a ventilation system that tempers the incoming fresh air and exhausts stale air from the home.

Sample RecoupAerator Install Example (box with green label)

The recommended ducting for the system delivers fresh air at ceiling level and returns at floor level. The unit can also be incorporated into a furnace system.

RecoupAerator Duct Option

The unit needs to be sized to deliver the right amount of ventilation for the space. Ultimate Air is a variable speed unit from about 60 cfm to 200 cfm that will serve up to a 3000 square ft home. But the actual calculations are based on ASHRAE requirements for home ventilation based on either square or cubic foot of space inside the home.

Posted in Appliances, Energy Efficiency, Ventilation | Comments Off

Designing Ducts

Posted on March 7, 2015 by ellen

Duct Design has been a bit tricky. The information about designing a suitable duct system for ventilation only has been difficult for me to find and interpret. Most duct design documentation is for heating systems and the fan speed numbers don’t seem to apply to an ERV with a variable speed fan. I was able to adjust a duct design from another ERV example to illustrate the layout for the supply ducting for our system.

Duct Layout

We are planning to limit the supply ducting to the remodeled area. Some of the air will blow back to the rear bedrooms from the living room while the returns will be located centrally in the pantry closet where the ERV will be located. Ventilation air will be released close to the ceiling and drawn in through stale air returns both above the ERV. The ERV comes with 6″ duct connections but to distribute air in our rather direct system, we will have to increase that to at least 8″. My first design was for 8″ supply and 6″ distribution but that won’t supply enough air except at the highest fan setting.

I learned this by asking the Ultimate Air folks what the static pressure should be in the system. That total static pressure determines how much air can be lost in the duct work itself. No fan can overcome a static pressure that is greater than its design capability. Although that seems intuitive, determining the fan’s capability at a certain duct length and diameter requires duct length tables.

The documentation for the RecoupAerator says not to exceed 7-8 inches of water column (in/wg) but that is the very highest resistance allowed to deliver air at the highest speed. For lower speed they recommended we keep the static pressure at 4 in/wg. So back to the drawing board.

Another confusion was the fan performance curves often published to determine sizing for a ventilation system. I could not understand the RecoupAerator curve as it was basically flat. Another question to their experts revealed that is because the fan is variable. It puts out steady air pressure all along the performance continuum.

Typical Fan Curve

Ultimate air fan performance curve

The typical fan curve shows the delivery of air changes as the length of the duct and the static pressure i.e. resistance in the ducts increases. So the fan delivers fewer cubic feet per minute of air the higher the static pressure and the longer the duct work. But the RecoupAerator from Ultimate Air has a continuously variable fan that works harder as the duct length increases and the static pressure increases but only up to .8 in/wg at 200 cfm. If there is more resistance the fan cannot deliver 200 cfm. Also this curve doesn’t show the static pressure for lower speeds which works the same way. If you want to run this fan on low speed and deliver air through the ducts the static pressure can’t be more than about .4.
So although using .8 in/wg for the duct system works with 6″ ducting in the run I planned above, the system would only deliver enough air at 200 cfm or the highest fan speed.

Posted in Planning, Ventilation | Comments Off

Flir One Floor

Posted on March 2, 2015 by ellen

Here is an infrared photo of the radiant pipes heating up in the slab. The temp shows the warmest temperature spot (red) to be just under design temperature (86˚) for the floor at zero outside. This photo was taken before the floor was entirely heated. The design temp keeps us comfortable and cozy inside and in fact the radiant heat works very well. An infrared camera allows you to “see” where the water pipes are located.

Radiant floor–just below design temp for zero degrees

The front door has a great deal of leakage underneath. We usually put a piece of polyiso in front of this door when it gets really cold. It will be replaced by a new ThermaTru-Alpen door in late March.

Cold leakage under the door

Another eye opener in the house was the temperature difference of the unprotected foundation wall on the east side of the master bedroom. This one will have polyiso insulation glued to the inside to eliminate this thermal break in the wall.

Uninsulated foundation wall on east side of Master bedroom.

The Flir iphone applications allows an image to use one of four emissivity settings. Another app records the high and low temps and temps of individual spots on the photo. The temps recorded depend on the accuracy of the setting. In this photo the high and low temps recorded outside are exaggerated with the high emissivity setting.

Exterior Flir Photo

The Flir One is a great tool but not accurate enough for official LEED evaluations. LEED requires not just a level one thermographer but a level two which requires more training. Infrared photos for our LEED evaluation will reveal any issues with the insulation installation that is not fully uncovered in the part of the house that we are not tearing apart entirely. That will determine the number of points that we earn for the thermal envelope. So I’m looking for someone who is a level two thermographer too.

Posted in Air Intrusion/Thermal Envelope, Tools | Comments Off

Flir One Sons

Posted on March 2, 2015 by ellen

My Flir One Sons as captured by my Christmas present to myself, a nifty iphone infrared camera accessory.

Flir One Son #1

Flir One Son #2 with temp spread in sunlight

Earlier last year I splurged on an iphone after using the first G1 for six years–but it was just before the iphone 6 was released and I wanted to be sure to get an iphone 5s because it fit the new infrared camera device from FLIR. The Flir One for the iPhone was released at $359 but it was reduced to $259 around Christmas time and then I had a $100 gift certificate from Apple so I bought one of these nifty cameras for myself.

The next larger camera is about $1000 and having an infrared camera to capture the temperature differentials in the rooms allows us to determine where more sealing is required and to measure the warmest and coldest temperatures in the house. There are other uses as well, and soon everyone will have an infrared camera in their tool bag but for now they are definitely a “geek” toy, I mean tool.

Posted in Tools | Comments Off

Time out for an RV trip!

Posted on February 26, 2015 by ellen

RV in New Mexico Desert

Yep, we are retired and I have always wanted to be able to get away in the RV for a couple of weeks. So we left for two weeks in February to explore New Mexico. On the way back we stopped to soak at my favorite hot springs so far. Pagosa has lots of smaller tubs and a nice sized swimming pool so that it is comfortable to soak outside even in temperatures down into the teens.

Pagosa Hot Springs

It took us three camping nights to make it to Carlsbad Caverns where we toured two days while staying at Guadalupe National Mountains.

Carlsbad Cavern

On the way back we stopped to hike near Albuquerque, stopped at White Sands, Hatch NM for hot peppers, and Chaco Canyon Pueblo Ruins. Very impressive.

Chaco Canyon Pueblos

We got home just in time for our grandkids birthday parties!

Posted in Diversions | Comments Off

Window and Door Performance

Posted on February 4, 2015 by ellen

The best performance is expensive, but is it more expensive than it is worth? I hope not! Here are the tested performance values for the 525-S Alpen window and doors that I chose. All the 525-S window panels are glazed with 2 panes of glass and 1 of film with argon fill. The depth of the panel is 1 3/8″.

Style	U-Factor	R-Value	SHGC	VT	Air Infiltration
Picture Window LP	0.17	6.3	0.3	0.49	0.01
Casement Window	0.19	5.3	0.24	0.38	0.01&.02
Picture Window LP	0.17	5.9	0.48	0.62	0.01
Casement Window	0.2	5	0.38	0.48	0.01&.02
Awning Window	0.19	5.3	0.24	0.38	0.01
Patio Door Glass	0.19	5.3	0.41	0.53
Patio Door Frame	.27/.18	3.7-5.5			.02 & .04

The air infiltration figures are particularly high performing. I read that the NFRC cannot test lower than .01. I found this chart comparing the difference between air infiltration rates for a 12 x 12 room in hours to change the air completely.

Window Air Infiltration Rates

Although the u factor and r value are higher for the sliding patio units, the uncontrolled air change rate according to this chart would be 9.1 hours, while the patio doors would leak a full room of air in 16 hours. The casement windows will take 64 hours to allow enough air in to replace all in a 12 x 12 room. Lots of difference in the air infiltration rates.

The solar heat gain coefficient numbers are not high for the south facing glass but they are the highest I could find with low u factors. Visible transmittance or the “clearness” of the glass is about half that of untreated glass except for the low solar heat gain windows on the north, east, and west.

These are current day high performance windows and doors, but they are sure to improve in the next 30 years so that one day, another owner will replace them with truly energy efficient units!

UPDATE: At the last minute I decided to upgrade the door inserts to the 725 glass. This unit has two layers of film inside and for the doors, the upgrade was very reasonable.

Style	U-Factor	R-Value	SHGC	VT	Air Infiltration
Patio Door Glass	0.18	5.6	0.41	0.53

Posted in Air Intrusion/Thermal Envelope, Energy Efficiency, Green Building Interests | Comments Off

More Window and Door Decisions

Posted on February 4, 2015 by ellen

Alpen Window Corner

I spent the whole morning with Mark Attard from AE and we finalized the order for the windows and doors. I was not completely happy with the limit on door options, but I hope I picked the best of each option available.
Mark brought a frame corner and color samples which was great because it was hard to imagine the “sandstone” color. Actually it was more beige than tan so we ended up picking a darker brown just not quite as dark as the bronze in the sample. Believe it or not the sample and the window are two different colors. I was tempted to go with a brick red but Dave preferred the brown and thank goodness I had a second opinion to rely on.

Alpen Color Choices–Buffalo and Black

I took a couple of pics of the insulated fiberglass frame too and the metal strips are the new 525-S spacers.

Alpen Frame Insulation

The door frames are purchased from Therma Tru–the best match is the Smooth Star version. Unfortunately, Alpen does not offer the full range of Therma Tru doors. I could only choose single and dual panel inswing hinged doors. Any sidelights would have to be Alpen frames which don’t really match the doors as well as the integral versions. So I chose full lite single panel opening doors for the front door, master bedroom door and east hall back door and dual panel full lite french patio doors for the large south living room area. Three 69 inch doors fit the space almost perfectly though so there is little to complain about. We will figure out how to keep the inswing doors out of the way in the hallway. The doors don’t come with screens but we should be able to screen them not too expensively with regular big box screening.

All I have to do is sign the contract and send in the check and the order will be on its way. Mark also recommended an installer and we have that quote and will use his expertise because he works with Mark and will seal everything with AE offered products which are the SIGA line. WOW this is a big step! ($$$$)

Posted in Air Intrusion/Thermal Envelope, Energy Efficiency, Planning | Comments Off

Alpen 525-S Windows

Posted on February 2, 2015 by ellen

Alpen HPP makes “cadillac” windows in my opinion. The specifications are far beyond Milgard as I’ve pointed out, and they have a lot of information available about their windows on their website that shows the quest for very high energy efficiency in their products. There are many recommendations for the windows on green building forums and sites. Some prefer the uPVC technology from Canada or Europe for a bit higher ratings at less cost, but uPVC is a cheaper product overall than fiberglass so I’m not impressed by the differences.

As mentioned before Alpen uses a “Mirror Film” technology that is manufactured in Chicago by Southwall and unlike other window companies has had success with its use. This film creates a third or forth pane within the window to capture heat and lower the u-values. They pair this technology with a super insulated fiberglass frame that holds its shape and spacers that maintain a good seal within the window. They offer a limited life time warranty to the original owner/purchaser of the windows, excluding color fade, screens, and labor. Still a very good warranty in the industry.

Originally I had Mark send a quote for Series 725 which was the Alpen mid range window. Since then Alpen has released an upgrade version of their 525 series using a new spacer that improves the performance.

Energy Star uses the test data from the National Fenestration Rating Council to determine efficiency. The data used are U factor, the measure of heat transfer through the window, Solar Heat Gain Coefficient, the measure of solar energy transfer (low ratings block heat from the sun), Visual Transmittance, the light that gets through the window–higher values equal more light, air infiltration, the measure of air leakage through the closed window and Condensation Resistance, the amount of condensation that builds on the window surface.

Generally the more expensive the window, given similar construction materials, the better the NFRC figures, at least that is what I have found in shopping. I wanted to find the best figures for the money. That is an arguable measure. My daughter’s new windows and doors are Energy Star. They have the minimum ratings to make that designation and perform well for her normally built stick house. The cost was typical builder supply cost and that is about an order of magnitude lower. So $300 retail for a door vs. close to $3000 for a special order high performance door. Custom special order doors are also that expensive though so compared to Pella or Anderson or even the more energy efficient Milgard, the price difference is much less. We are trying to produce the most energy efficient, highest LEED rating, closest to Net Zero home that we can afford and that makes sense for the final value of our property.

Even within the Alpen window lines, the 725 was mid-range with great performance, but the 925 is their highest rated window–and has Passive House approval. But they are even more expensive. We would have gone with 725 but Mark’s advice is that the 525-S is a better “deal”. Great performance for less cost.

The 525-S series has better air infiltration figures than the 725. The seal must make the difference as the numbers typically are .05 for the 725 and .02 for the 525-S. Otherwise the 725 have lower U factors. A fixed glass low profile higher solar factor window is .16 while the same 525-S fixed glass window is .17. So with that difference we have switched to the 525-S series for the more affordable performance.

Posted in Air Intrusion/Thermal Envelope, Energy Efficiency, LEED Project, Local Products | Comments Off

AE Building Systems

Posted on February 1, 2015 by ellen

I was fortunate to be referred to Mark Attard at AE when I contacted Alpen for a quote. He is very involved in the Passive House interest group in Colorado and AE Building Systems carries a full line of products to achieve excellent thermal efficiency in any building.

We purchased the Siga air barrier from AE and will also buy the Ultimate Air RecoupAerator Energy Recovery ventilation system from them. So Mark is an important partner in our LEED certification quest.

So far Mark has completed 13 quotes for either the entire set of windows and doors or partial quotes for variations. We are still not to the final quote, but getting very close.

Mark also carries Intus doors and windows. This is a European company that sells uPVC windows and doors as well as aluminum clad wood. I really like the aluminum clad wood, and they make outswing french doors and “window walls” that slide completely open. My friend Sarah the architect, who grew up in the house recommended we look at Nana Walls that open like this. I contacted the rep in Colorado but found that their aluminum version would cost about $20,000 for the 212 inch space. Intus’s folding wall option in aluminum clad wood is about the same. Filling the opening with two sets of outswing french doors costs about $12,000 from Intus and using Alpen sliders is closer to $7000. The sliders have the best u values so the Intus can gain just a tiny bit on the SHGC (.47 vs. .41 for Alpen.)

I didn’t want the openings to protrude into the “solar hall” space as that is the main passage between the entry and rear of the house but our last house had a slider and I always wanted to replace it with a french door. Also we had sliders on our first home and they stuck after several years. One set we replaced with an outswing french door and we really liked that door. It worked well off the kitchen and did not require space in the room itself.

But Alpen does not offer outswing french doors. Mark said outswing doors have sealing and longevity problems so don’t meet Alpen’s specifications at this time. They are working with a uPVC company to put their glass in uPVC windows and doors, however, I really want to put in fiberglass due to its proven durability and I prefer the locally manufactured products from Alpen.

My daughter just had me look closely at her home improvement store inswing french doors. She said for the money, the energy efficiency and operation of the doors is much more cost effective. She has a point. The doors are about .3 or close to the high end Milgard, but the low e coating really limits the heat from the sun. Her doors are on the south side of the house too. But they do open all the way so that if room was provided for them to fold back against the wall, they could open the space in a similar way as outswing doors would. So again I may ask Mark for another variation.

In my defense if I had access to the product software, I could do all this work myself and would love it. As it is, every time I consider an alternate style or design, Mark has to send me another quote. This has been time consuming for both of us.

There is also the installation that we have to think about. Mark works with an installer who is coming out this week to look at the job. We will be able to expose the studs inside for the new windows but the outside is covered either in siding, masonry, or stucco, so the windows probably won’t be able to use “fins” to seal against the building. Instead we will use an attached aluminum brick mold that Mark recommended to trim out the outside of the windows and seal under that, then use foam around the units. Our current windows have a brick mold and use spray foam to seal them so that should work great. Instead of fins the windows can be equipped with brackets to attach them.

Although we are excited to be making this big step in the energy upgrade to this house, it is also a tense time, making the right decisions and having the foresight to have high energy efficiency, workable openings, and attractive design is time consuming for us and our vendor.

Posted in Air Intrusion/Thermal Envelope, Design Style, LEED Project | Comments Off

Local Manufacturers of Windows and Doors

Posted on January 31, 2015 by ellen

We live near Denver, Colorado. Locally manufactured items qualify for LEED points if they are made within 500 miles of home. There are several local manufacturers of vinyl or uPVC windows in that radius but far fewer for fiberglass. Milgard, one of the largest window manufacturers in the U.S., have had manufacturing facilities in Denver, Colorado since 1996, although they also manufacture at other sites outside the 500 mile radius.

Milgard Wood Clad Casement

Among the most energy efficient windows made in the USA, Alpen High Performance Products manufactures in Longmont, CO. They have been making energy efficient windows since the 70’s. Although briefly owned by Serious Windows in CA, ownership transferred back to Alpen in 2012.

Alpen Fiberglass Casement

I fortunately found a website that allowed me to cost out Milgard windows and doors. The Window Store is located in California but my quote showed that the doors I would order would ship from Denver–and I had the option of picking up the order to save the shipping of $150. I was thrilled to work with the software putting in the numbers for the doors and varying the configurations. I got lots of idea about how to arrange the large window/door area and used the overall quote to get an idea of the pricing on higher end fiberglass doors with wood interiors.

The cost of Milgard doors is about 20 to 30% less than the fiberglass high performance options from Alpen. But the numbers are not nearly as impressive. For French doors the u factor is about .29, the solar heat gains are low with every choice of glass–about .2 and lower and low visual transmission figures too. The numbers for the Alpen solar heat gain glazing option on a sliding door is a u value of .19 and SHGC of .41. That is impressive and qualifies for “Very High Efficiency” ratings from LEED.

Alpen windows and doors offer a “triple pane” option by using an interior film to improve u values. We already have two windows with cracked films, but there were lots of film failures in the 80’s and 90’s while Alpen seems to have had success. Apparently all these films come from Southwall (now owned by Eastman Chemical) in Chicago and they manufacture “Heat Mirror IG”. The company was sued for many failures but they won the cases because the other manufacturers did not follow the specifications published by the company. There are several window companies that use the film.

Milgard also states higher air infiltration rates than Alpen–.1 and .07 for Milgard and .02 for Alpen for 525 series casement windows. So Alpen is our first choice for the new windows and doors for the house.

Unfortunately although the Milgard options have wood clad interiors for both the windows and doors, Alpen offers wood clad fir or oak only for windows.

Also I had hoped to purchase outswing french doors for the living room to really open up that area to the courtyard, but Alpen does not offer them although Milgard does. They do offer both inswing french doors and sliding patio doors.

Configuring new windows and doors differently from what is already installed can be very tricky. We are working on that configuration now and have gone through almost every option we could think of for the doors and several for the windows.

More about the ordering process next.

Posted in Air Intrusion/Thermal Envelope, Energy Efficiency, Local Products | Comments Off

Window and Door Decision

Posted on January 30, 2015 by ellen

I’m in the throes of deciding about the replacement windows and doors. After the total replacement of the slab in the main part of the house, this is the most expensive single energy efficiency upgrade.

Our current windows are all wood and double pane, the large picture windows do not have frames but are just the glass panels installed with spray foam borders. Since this house was built to be energy efficient, the windows are very well sealed with foam. But the picture window seams have deteriorated so that the seal is cracked and they form precipitation inside and one pair in the family room had interior film which has cracked severely.

Moisture between panes

Cracked window film–both window films are cracked now

The windows are deteriorated on the outside due to neglect too. They are cracked and peeling paint and some of the glazing trim is missing.

Window damage

I had a couple of window specialists come out to estimate the cost of repair and replacement of the glass and the estimates for glass replacement were in the $10,000 range. So the easiest repair is to just replace them. The doors are just old and need to be replaced because their functions are changing and we might as well get better energy efficiency in new doors as well as the windows.

LEED has two paths for energy rating the house. One is prescriptive where each type of energy efficient component is scored separately and a large number of points are given for solar panels that offset electrical usage. The other is performance based where fewer points are awarded for individual choices of energy saving components but the prerequisite is based on the Energy Star Thermal Bypass checklist and points are awarded according to the HERS rating. Of course all the individual choices are then transferred to the checklist and to the mysterious HERS formula, but the overall rating (performance) earns the points instead of each choice.

So I don’t have a clear idea how the new windows will play into the HERS formula (Doors are apparently excluded) and the prescriptive path points to the Energy Star builder options to define “best” windows, which can changed if the ratio of windows to floor area is 18% or higher. Since our house is passive solar, our ratio is high. We have LOTS of south facing glazing. But for the whole house, the percentage of windows to our floor space is less than 16%. So we wouldn’t have to meet an even more stringent threshold in the prescriptive path. (at any rate for our Northern climate it is the limit of 18% divided by the existing–say ours was 20%–times the Energy Star required u value for our climate zone–less or equal to .4 or a required u value of less than or equal .36)

There is an additional LEED point for buying locally manufactured products, so one of our first choices is Alpen windows. They are both highly energy efficient and manufactured in Longmont, CO. which is very close to us. But the price tag is a bit overwhelming and we are limited to the glass they offer in their windows and doors. My biggest concern is the solar heat gain coefficient, or the fraction of available solar heat that the windows pass for heating our passive solar home. Single pane clear glass is close to 100%, most low-e coatings that improve u values reduce that considerably. Most big box doors and windows have SHGC of less than .3 which means that less than a third of the available solar heat passes through the glass due to the low-e coatings. Alpen offers a higher rating of .41 as a glass option. Although that is still below 50%, it is one of the higher SHGC ratings that also have low u values.

I’ll explain more about the Alpen windows in another post. But for now, we are getting quotes to replace all our windows and doors and Alpen seems to be the best bang for the buck.

Posted in Construction, Energy Efficiency, Local Products, Planning | Comments Off

LEED Checklist

Posted on January 6, 2015 by ellen

LEED for Homes

Recounting where we are and where we need to be certainly requires a look at the LEED checklist. We are planning for most of the same points as in our preliminary rating and Platinum certification. Although some of the points we had hoped to gain will not be possible, others may be added.

Due to our long term project timeline all of the experts included in the design charrette could not be involved in all phases of the project and meet regularly so that point is not gained, but we didn’t lose any other points in Project Planning.

The durability checklist is being followed and we should gain all points for addressing these issues: air infiltration, radon, and ground moisture under the slab. We hope to apply for the innovative use of the waffle mat slab to control the heaving due to ground moisture too. For durability the bathroom in the crawlspace area of the house will have to be re-tiled with waterproof backing as the demolished bathrooms were tiled on regular drywall and waterproof backing in the bath/shower area is a requirement.

Energy Logic is due to be our third party evaluator so for Innovation and Design we should earn 7 points.

Location and Linkages have basically not changed since our preliminary rating for a total of 7 points.

In the area of Sustainable Sites, we have worked to improve the landscape and have the professional landscape and irrigation plan. Unfortunately several of the trees we planted for 50% shade of the driveway have died. We are planting again this spring. Dave has started some hand terracing to capture natural runoff for trees and is building a garden wall that terraces the vegetable garden. We have very little impermeable paving compared to the size of the lot, and all the plants except for the vegetables and fruit trees will be drought tolerant varieties. A few plantings have survived the rabbits. Although the calculations have not been done for water reduction, there should be some based on the changes in the irrigation system. Without whatever points the watering plan will gain, we should have at least 14 points in Sustainable Sites.

We still predict 10 points in Water Efficiency due to Water Sense faucets, low flow showers, and low water using flush toilets as well as a reduced and highly efficient irrigation system.

It appears that the performance path is the best option at this time for Energy and Atmosphere. That means passing the thermal bypass inspection and obtaining a low HERS score. If we can meet our goal of 40 we will gain 26 points with one of those for pipe insulation and another for not having air conditioning.

Salvaging the lumber from our deconstruction, purchasing used and recycled materials for the shell and finish materials and diverting a great deal of our construction waste from the landfill will gain us several points in Materials and Resources–at least 13.

We have lots of work to do yet for Indoor Air Quality. The ventilation system has to be installed, and the Energy Star Air Plus requirements must be met. The garage needs a vent fan that runs on a timer when the garage door is opened. But all the combustion appliances have outdoor venting, the radon system is installed, the airlock entry with shoe removal facilities is designed. We should have third party verification on the indoor air quality and a backdraft test on the wood burning boiler so that we could qualify for all 21 points in this category.

Finally the Awareness and Education requirements are starting to be met with this blog, the presentation about our project at the Sustainability Fair, which may take the place of a newspaper article, and open houses that will probably happen after the window and membrane installations for the Passive House group and perhaps for USGBC Denver. The advanced training that I took for LEED green rating qualifies for enhanced homeowner training. I have already started the user manual and an advanced technical manual will also be written. We should qualify for all 3 AE points.

The projected total with a couple of points for irrigation reduction is about 103 points so we have a few to lose and still make the 94 point Platinum level. But there is still a lot of work ahead.

Posted in LEED Project | Comments Off

Inspections to Complete in 2015

Posted on January 5, 2015 by ellen

So far we have had two building permits and five or six visits from the Arvada inspectors.
The first building permit was for demolition and the under-slab plumbing. We passed after two or three visits from a very nice inspector who did a courtesy inspection to help us prepare for the actual inspection and then helped us be sure all the piping had the correct fall. That was a good experience when we had none with building departments. We consider ourselves fortunate to be working with a helpful and friendly building department.
We were then able to move ahead with the re-building permit in February 2013.
The foundation layout was approved easily because we had the engineer’s drawings and his written approval. And as part of that inspection, the radiant pipe layout and underground HVAC was approved. These inspections were done in March of 2013. We spent the rest of 2013 working on the HVAC boiler install, finishing the demolition by removing the rest of the drywall, the kitchen attic, and all the fiberglass insulation. Then we ordered the new rockwool insulation and started the installation. All of this on a part time basis of about a week a month.
When 2014 rolled around and Dave retired, we had lots of work to do to get our Arizona house sold, move, and get settled in the unfinished house. The permit had to be renewed in March and all that was accomplished was installing the insulation and tweaking the boiler and hot water return installations. Work in Arizona on the move and house sale took up most of the winter and spring. The house sold after lots of remodeling and upgrades at the beginning of June but took until late July to close.
In the summer we were pretty distracted from the remodel due to a trip to Indiana and our son’s wedding in California. So when we renewed our permit in September, we didn’t have much to show for a year of effort. Then when we got the gas line installed in October, the inspector approved the installation and the HVAC except for the ventilation system that is yet to be installed.
We need to get to the next inspection before our current permit has to be renewed in March because we must be able to show constant effort or the project could be considered abandoned and we would have to purchase a new building permit.
Here are the remaining inspections for the building. The head of the Arvada building department is expecting us to finish these steps in 2015!
Insulation
Rough Framing
Rough Electric
Rough Plumbing
Partial Electric
Drywall
Final HVAC
Final Plumbing
Final Electrical
Final Building
We can call for the insulation inspection in a couple of weeks and hopefully get an electrician who will install the rough electric by the end of March.
We could install the ventilation system and ducting to get the Final HVAC inspection in March too.
Installing the new windows and doors will need to be done about that time to finish the outside walls. Then we can build the inside walls in April and May and rough in the plumbing, so we can get the rough framing and plumbing inspections in late May or June.
Partial electric to all the outlets and light fixtures should go in next and then drywall. I figure those should be ready by September.
Of course these are rough estimates as to timing. Remember the two questions I can never answer? How long will it take and how much will it cost? We are trying to meet a schedule, but we want to be sure that everything is done as well as possible and according to the LEED and Energy Star guidelines so that takes time and attention to detail.
But the plan is that by next New Year’s we will have the final building permit passed and closed.

UPDATE: The hoped-for progress in this post was far too ambitious for reality. The only inspection completed in 2015 was the insulation, a rough electrical was denied but that was a courtesy inspection i.e. one to find out what had to be done to pass.

Posted in Air Intrusion/Thermal Envelope, House Systems, Inspections, LEED Project, Planning | Comments Off