Energy Efficient Home enables early retirement

I had a great chat today with Linda Johnson, the owner of the passive solar home I built, featured in this blog. I try to touch base with her on a regular basis, just to see how the house is working and if she has any problems with it. She also sends me her energy bills on a regular basis which enables me to keep track of how the house is performing. Yes, we did a whole bunch of energy modeling when designing the house but nothing beats having the actual energy costs to prove that this stuff works and works well.

She just turned 62 (she's gonna kill me for telling that) and she will be retiring within the next few months. Then she went on to tell me that had she not built this house she would not have been able to retire at this age. She stated that she is saving $550 a month living in her new home, even with having to pay a little more in property taxes. I'm not sure how she did the math but it was nice to hear. In another month or so she will have been in the house for 2 full years and we will once again compare the annual energy costs to make sure the house is meeting expectations. Early on, back in 2008 when I was first getting ready to build this house I estimated the annual heating costs of the house to be less than $700 and the total energy cost to be about $1,500. Last winter the cost to heat this home came in at $341 for the entire winter, far exceeding expectations. The total energy cost for the house over the entire year was $1,786 about $286 higher than expected, so we sat down and tried to figure out were the extra energy was being used. We made some adjustments to the cooling system that helped the system perform more efficiently, we adjusted the setting on the whole house dehumidifier and we made recommendations about habits that could reduce energy costs. We will see in another month how well those adjustments worked and if we have met the goal of $1,500 annual energy costs. Next we will be installing a solar hot water system that should reduce the energy costs even further, ( she currently has an electric hot water heater)

Tracking the energy costs for this house has been pretty simple, it's all electric. No oil, gas or wood, no fossil fuels being burnt in the house and the ability to convert to solar electric, should she choose to do so. That will be the next step to fulfilling the goal I had when designing this house, a true zero energy home, right here in New England that costs less than $175 sq/ft to build.

Tom Pittsley

ecobuilder@aol.com

http://www.eebt.org/

New passive solar home underway

Construction is fully underway at a new passive solar home I am building and we are using the next generation of thermal mass windows. An incredible achievement in passive solar technology, capturing and storing the suns energy in your windows.



Since last posting here I have joined forces with Next Step Living inc. a Boston MA based company that is leading the way in energy efficiency and having a substantial impact on improving our existing housing stock. A very challenging and rewarding job to say the least.

We have begun building a passive solar home located in central MA in the town of N. Brookfield. To follow this new project here is the link to the new blog.

http://www.nextsteplivingnewhome.blogspot.com/

Tom Pittsley
ecobuilder@aol.com
tom.pittsley@nextsteplivinginc.com
www.eebt.org

Heating a home in Massachusetts for $341 a year

If you have been following this blog, it has been a long time since my last post. In May of this year the homeowner of the house (highlighted in my previous posts) has been in the house for one full year. I collected all of the energy bills for the last year and sat down and did the calculations. It was pretty simple to figure, as the house has only electricity for it's energy supply. Well let's not forget the solar energy that is used to heat this home. No, no solar panels on the roof, no solar hot water, and no PV, just plain old passive solar energy, combine with an air tight, highly insulated envelope. We also cannot forget the windows. Take a look at one video that shows the windows reaching 112 degrees on a 34 degree winter's day.

So after sitting down and calculating the energy costs for the home, it was pretty clear to see how well passive design and the right windows can reduce your heating costs. To calculate the heating costs for the winter months we calculated the monthly base load used throughout the year and then deducted this from the actual usage to come up with $341 for heating this 2,000 sq/ft home for the entire year. One factor that cannot be calculated into costs and that is comfort. Comfort is the thing the homeowner talks about whenever I see her. She can't believe how comfortable her new home is, warm windows on a cold winters night, unheard of here in New England. The windows never actually go below room temperature even on the coldest nights.

I am about to begin my next project and this one is going to be even better than the last.

New Thermal Mass windows are finally ready for a test run in a real home and the lucky recipients, the Melad family of N Brookfield MA are getting the latest development.

The new windows were finally made public this last week, with the debut at the 2010 AIA national convention in Miami, finally my silence can be broken. I have been working with the inventor for the past few years but always stifled by a non-disclosure agreement and have been anticipating this for more than a year now. These new windows are the most advanced window product you can find, they capture, store, absorb and reflect solar energy. How can they do all that? The glazing system used for the windows has a unique combination of glass, low-e surfaces, gel to create a window with an R-5 (U-.2) insulation value and a SHGC-.72 along with mass capable of storing thousands of BTU's on a sunny winter day. This window has 4 panes of glass, the two inner layers have a clear gel encapsulated with the space between. This clear gel acts as a thermal mass and stores the suns energy, much like the water did in the previous version. The thing that really puts the icing on the cake are the shades. The newest version has motorized shade system that retracts up into the head of the window and hides itself away when the house gets to warm. They can be controlled by a simple thermostat placed near the windows and be set to close at your desired temperature. Pretty cool, huh!!! With the shade down the SHGC drops to .144 twice the reduction needed to reach the energy star rating for low SHGC. I am awaiting the latest press release with all the details about the product. Here's the tough part, you can't get them yet. They still haven't put them into production and are not available to the general public yet, but after their debut at the AIA conference it is just a matter time. Stay tuned!!!

Tom Pittsley
ecobuilder@aol.com
www.eebt.org

Passive solar home construction: Walking the walk

I have been talking the talk for a long time, but walking it is a different story.


Building a passive solar home and designing one are two different things, measuring it's performance is another. While over the years I have built several homes that were designed for passive solar all to some varying degree. In 2008 I had the chance to design and build a passive solar home for Linda Johnson and her two children, Rachel and Max. After over twenty years of construction, the last ten having been dedicated to building better buildings, I finally had my chance to use my years of knowledge as a Design/Builder to create the most energy efficient home I have ever built. It was great to work with a home owner to design the home of her dreams, while I focused on ways to reduce the energy demands and cost of the homes construction. Below is a list of the house specifications, along with the total energy usage to date.





Location: Middleboro MA

Size: 1,976 sq/ft = 183.5/sqm


style: Modified single level ranch style

3 bedroom, 2 bath, kitchen/dining/living, laundry, utility, and entertainment/wetbar


Oriented to capture as much passive solar as possible 180 degrees south along long side 68'

Roof slope maximized for active solar to be added in the future, conduit in place

Cost of construction $269,000 plus extras and appliances total cost of $290,000

$135 sq/ft base costs $145 sq/ft final cost

10% ratio of floor to south facing glazing,196 sq/ft, 46 sq/ft conventional,
150 sq/ft of specialized thermal mass windows: More info on these windows

Completely insulated slab-on-grade foundation w/integrated radiant heating/cooling R-15

6-1/2" Structural Insulated Panels for all exterior walls R-24

10-1/4" Structural insulated panels for the ceiling 1,300 sq/ft R-40, conventional frame above

7" of closed cell spray foam in cathedral roof section between conventional rafters,940sq/ft R-40

Additional insulation at sill points to address thermal bridging

Air sealing,using negative pressure during construction to find and seal all air leaks

Heat Recovery Ventilation system w/programmable control

Ground source heat pump to provide heating and cooling to the radiant slab

Energy efficient appliances

Whole house De-humidification system

All energy supplied to the house as Electricity

Date loggers to record efficiency of systems and monitor comfort levels for Temp/Humidity

The standard for total annual energy use under the Passive house Institute standards is < 120 KWh/Sqm. To meet the standard this house would have to use less than 22,000 Kwh's annually: 183.5X120=22,020.
While the house is about to undergo it's first New England winter while occupied, the performance to date has been consistent with the energy model. The house has been occupied for 6-1/2 months now and the total energy used to date is 6,020 Kwh's. If it continues through the winter meeting the expectations the total annual energy consumption will be around 12-14,000 Kwhrs surpassing the standards set by the passive institute by 33% or more. While I didn't do a blower door test to measure the air leakage rate or have a way to separate heating energy from total energy, the final Kwh's of energy consumed will be the measure. No complicated measure devises and costs, just the electric meter the electric company provides. We have been logging the energy use by simply reading the meter at different intervals and recording the actual energy consumed. On April 20th 2010 the house will have gone through one full year of occupation, on that date I will be able to confirm if it has met or exceeded the standard.

It's going to be a long winter's wait !

Tom Pittsley
ecobuilder@aol.com
www.eebt.org

Window shading for a passive solar home

We just finished posting a video on YouTube showing how well the window shades developed to compliment our thermal mass window system work. while it was specifically designed to work with the thermal mass windows, these shades can reduce the cooling needs of any home that experiences solar heat gains during the cooling season. These are the first prototypes to be installed on a home and are functioning to reduce the cooling needs of this home dramatically. I will post more about the geothermal cooling system when I have some time, but lets just say that is far from conventional.




Tom Pittsley
ecobuilder@aol.com
www.eebt.org

Solar green home completed and performing as hoped

So, it's been a while since my last blog. In the beginning of April, we held our open house. It was great, we had over 75 people come by and take a tour. The homeowner has since moved in and is enjoying her new home. In mid February we first fired up the heating system in the house and have been monitoring it since that time. During the first 32 days of the heating system running and the cold house being brought up to temperature, we consumed $157 worth of energy. Keep in mind this house is entirely heated by passive solar energy in combination with a geothermal heating system. The geothermal system is supplying the radiant floor slab with heat at 90-95F and maintaining the house at a very comfortable temperature even on the coldest days of February. I have to say the geothermal system is not a plug and play system. I installed data logging devices to monitor the system and the on/off cycles of the heat pump. After the first few weeks and some tweaking of the flow rates and delta T of the storage tank we finally found the right mix to make the system run at it's peak performance. What I have found is that very small changes to the flow rates can have a profound impact on how well the system runs. After all what good is it to have the most efficient heating system if it isn't working at it's peak.
We still have the solar hot water system to add to the house, we will be installing this in the next month or so. As of right now the domestic hot water is running on an electric hot water tank. Most people would think that this is not the most efficient way to heat water and I would have to agree with them, it isn't. So why would we put an inefficient hot water tank in a home designed for zero energy? I won't try and get to technical, but here are the basics needed for a solar hot water system. First you need a collector, then a storage tank, some piping, a pump or too, a controller including temperature sensors and an exchange, usually found inside the storage tank. What I have chosen to do in this case in separate the tank and the exchanger rather than combining them and here is my reasoning. Simple solar storage tanks are no different than a traditional electric hot water heater, other than a couple of existing ports to make the connections. These can be simply added to any existing electric hot water tank by adding a T at the intake and the drain port on the bottom. The cost difference is the thing, a tank sold as a solar storage tank usually costs twice as much and typically even more. What about the exchanger? Some tanks have an exchanger already inside of the them and they work excellent, but at what cost? Most of the solar tanks, that have the internal exchangers cost at least $1500 typically more like $2,000. If you separate the components and make the exchanger and the tanks separate you not only reduce cost dramatically but you also reduce maintenance costs down the road. By using and external heat exchanger you do loose some efficiency but not much. What do achieve is a system that individual components can be changed out as they fail, (somewhere down the road) without having to throw away the tank because the exchanger failed or visa-versa. Reducing the initial costs and making the system modular makes sense to me, what do you think?

The total energy cost for the house from Mid February till now has been about $400, not to bad given the cold temperature we experienced during Feb and March. So, this all electric house is ready for the next step, solar electric or PV as it's better known. For that we will have to wait, at least a year before making the decision as to the value of such a system. The cost for doing this has come way down over the last year and once the years total energy usage is determined then a system to meet these needs can be designed. all of the infrastructure for this is already in place. If my calculations are correct this home will need a 6K Pv system to meet the homes needs at a cost of about $35,000. It's hard to justify such a system if the total yearly energy costs are $1,500 as predicted by the energy modeling done before the house was even built.

I little tidbit about just how energy efficient the homes envelope system is, when compared to other homes and even some extraordinary ones. A typical home built in this area and insulated to meet the existing energy codes would use more than 2.4 times as much energy for the heating and cooling needs. Even a house designed for the Solar decathlon competition doesn't come close the efficiency achieved with this design. I am currently acting as an advisor to the BAC/Tufts University solar decathlon team, were they are currently building an 800 sq/ft home completely powered by solar energy as part of the DOE's Solar Decathlon competition. Their home, while being a great model of solar energy has a heat loss equal to my 2,000 sq/ft home. This house has a 11 Btu heat loss at design temperature. That means that the heating system for the house was so small we used the smallest one we could find to meet the heating and cooling loads of the house and it was still over sized by 30%. The maximum design loss for this house is 20,000 Btu's/hr at design temperature. That means this house will only use 20,000Btu's/hr when the outside temperature is 0 degrees and the sun isn't shining. Most homes heating systems are rated for at least 60,000 and most are more like 100,000 Btu's.

That's all for now, but stay tuned I will be shooting some new video's of the home including the new super low maintenance lawn we installed a few weeks ago. Pretty cool stuff, never needs watering once established, grow so slow you only need to mow it 5 or 6 times a year and never needs fertilizer. I hope it lives up to the expectations put out in the literature about this product, if it does I will be replacing my lawn next year. I love the idea of not having to spend a couple of hours every weekend mowing my lawn. Stay tuned.

Tom Pittsley
ecobuilder@aol.com
www.eebt.org

Passive solar home performance update

Here is a video with a quick update of how the house is performing, now that we have the geothermal heat pump up and running. Better to watch, than to try reading my writing!!

Stay tuned, the videos of the acid stained concrete floors is being work on and should be up in the next few days. These floors, while incredibly labor intensive, have a look, a feel and warmth you have to see to appreciate, people can't belive it's concrete. One of my friends, who is also my greatest critic, responded with a WOW when first seeing the floors. That's the kind of response you will have once you have seen this, come by for the open house and see it for yourself.

Open house coming in April, date to be announced.




If you are interested in building an energy efficient, passive solar or active solar home, that is what I do. Want to go all the way to zero energy? We can do that too. For more information contact me at ecobuilder@aol.com

Geothermal heat pump system

Although the house is using the sun to heat itself, there is a need for additional heating during the cold winter months when the sun isn't shining. For that purpose we installed a geothermal heat pump system to deliver the needed heat with the utmost efficiency. Yes, the system was costly but given how efficient it is, and the desire to have the home completely run by electricity, it was the most sensible option. The house is designed to be convertible to zero energy, once the total energy loads have been determined. ( PV array) The heat pump reduces the amount of electrical energy needed to heat the home.
How does a heat pump work? That is a sum what complicated answer, but the gist of it, is that it moves heat out of the ground and transfers it into you house by using a refrigerant, compressor and an expansion valve the system extracts heat out of the ground exchange while in the low pressure cold side of the system. Not the simplest thing to understand, how you can move heat efficiently even at temps as low as 32F, but it really works and works well. The other component of the system is the radiant floor slab, which allows for low temp water for heating. Once you have reduced you need for heat through super insulating and air sealing the systems cost is dramatically reduced. For this house we purchased the smallest heat pump that we could find, that would not only provide heat but also provide cooling.
Here is where we stuck our necks out. Not many people try and cool their homes through a radiant floor and there are several obstacles to doing this. First of all most houses require more cooling because the are not super insulated, radiant cooling has a limited amount of Btu's it can deliver. Another major obstacle is humidity and condensation which can accumulate on the floor, if you have rug, wood or vinyl this could be catastrophic. We have installed a whole house dehumidification system that can reduce the humidity in the air and also reduce the demand for cooling. You feel cooler when the humidity level is lower ( it's not the heat it's the humidity) reducing the need for cooling. But when there is a demand the humidity level can reduce the dew point and reduce the chance for condensation. Another part is the ceiling fans which may reduce the need for cooling or at least help to move the cool air off of the floor and circulate it around the room. If we do get condensation on the floor, it is not a major problem. The finished floors are stained concrete, so they won't be ruined if it happens and they won't hide the problem under the rug, making it easy to identify and rectify. Here is a video showing the heating and cooling system.



The closed loop, horizontal ground exchange system was shown on a previous video and gives you an idea how the ground exchange is installed.

This is one feature of the house that has been gaining in popularity in the last few years. It makes your energy cost less susceptible to the fluctuations of the fossil fuel market. Electricity cost do not rise 100% in a few months like the oil prices did over the last year, and enables this house the ability to produce all of the energy it needs to maintain itself. To make the final leap to zero energy is a costly one and given the inefficiency and cost of PV panels at this time it is not the most cost effective approach. However I do believe that PV will get better and the cost will come down, to that end an electrical chase was run from the attic space into the utility room for future use. The roof line was designed to maximize the solar gains and make use of all potential solar energy that is available on this site. Hopefully one day soon, the PV manufacturers will make a panel that is at least 30% efficient and costs less than the house itself. At this time the cost to install PV panels that would produce all of the homes energy needs would be between $40-50,000 and would take the full life expectancy of the panels to pay for itself. Not there yet!!!

Tom Pittsley
ecobuilder@aol.com
www.eebt.org

Green Building, from the ground up

While most of my blogs have been focused on passive solar energy,there is a whole lot more to building an energy efficient or "Green Building". I don't like to call myself a green builder, it sounds kind of trendy and that has never been my thing, but I have been following most of the basic principles for years. Lots of the things that are thought to be green also save money during construction, things like reducing material waste. My current project, has had half of the normal waste of a typically built home, great for the environment but also great for my wallet, I saved almost $1,000 in disposal fees for the project. I have at the homeowners request decide to attempt, to compile all of the green elements designed into this house. My latest video covers some of the features.


I want to take a minute to mention and thank Linda Johnson, (homeowner) without her this project would not have been possible. When Linda first came to me in June of 2008 and told me she had found a lot and wanted to build an energy efficient house, I was ecstatic. Here was my chance to prove that with good design, you could build a very energy efficient, passive solar home at a reasonable cost, and so the design process began. Working together we came up with a house that meets all of her needs while reducing energy needs and costs while using as much solar energy as is reasonably possible.
When I design a building I use a whole house method to make decisions, taking into account the added value and costs. It's kind of hard to explain, but many of the choices we make in the design phase will have an impact on not only the energy usage of the house, but also the costs as well. I have a unique advantage over most Architects, in that I don't just design the building but I also build it. I know how much in cost to build things and how the cost of materials and labor can be reduced through good design. Here are a few questions I ask myself when making decisions about design or materials, first: Does this save energy? Saving energy always saves money the next question is how much energy does it save? How much more does it cost, if it cost more? Is it better for the environment? Will it last longer? Is it produced or available locally? So, here is the list and some information about the advantages and disadvantages of each, most have overlapping advantages that work together to save energy and costs. I know I don't have enough time to cover all of it in this post, but I will continue it into others, when time allows.


Insulated slab on grade foundation

The insulated slab on grade foundation allows us to use the foundation as the heating distribution system for the house. It also has thermal mass properties that allow it to store thermal energy, and regulate the temperature fluctuations of the house. The floor controls the temperature in the house, if the floor is cold the house will be cold, if it is warm the house will be warm. By using radiant tubing embedded in the floor we can deliver heat to the house at a much lower temperature than with traditional heating systems, even better that most radiant systems, that are installed below the floor. The least expensive way to install radiant tubing. The slab only requires the heating system to provide 90F water for heating, under wooden floor radiant requires at least 130F water and forced hot water system require around 160-180F. The lower temperature needed for heating also increases the efficiency of the geothermal heat pump, another whole feature of the house that I will explain in another post. We are also using the foundation as the finish floor for most of the house. When the foundation was poured, we had the concrete guys finish the concrete slab just like you would a concrete floor, polished to a smooth surface. We then covered the floor during construction to protect it from the likes of the plasterers that would make the clean up a nightmare. The finish will be an acid stain with a sealer that will appear much like tile. We cut grout lines into the concrete making it look like a 18"x18" tile pattern, then the acid stain will be applied, neutralized, sealed and then waxed. Once completed it will appear as tiles, but no materials were shipped from afar and did I mention that the concrete used contained 20% fly ash, a waste product from local coal burning plants? No VOC's in the finishing product's.
The cost to do this is comparable to conventional flooring but most of the cost is in labor, making it better for me, not so good for the flooring suppliers, oh yea no waste from left over flooring materials.
So this is just one feature of the house that contributes to the green design, I will list more later things like how we reduce electrical and water demands through appliances and even some strategies to reduce vampire loads. How natural light is used to reduce need for lighting and how ventilation can be used to improve indoor air quality and energy use. How more insulation and reduced air infiltration can reduce the need for heat and add to comfort. How passive and active solar energy is incorporated into the design, that has the potential to make this a true zero-energy home. For me these things seem simple but trying to explain how all of the individual decisions made while designing a house, and all of the choices made regarding materials contribute to the energy and cost of building, is much harder to explain in writing. Here is a quick list of other features of the house.

Whole house design
Oriented for solar
Structural Insulated Panels
Heat recovery ventilation
geothermal heat pump
thermal mass windows
energy efficient appliances
HP adaptable
passive solar
active solar
recycled materials
durable materials lasting longer than 30yrs
low maintenance
water reducing elements
electrical reducing strategies
PV ready with electrical conduits run

I am sure I have skipped over some but I will continue this at a later date with more explanation of all of these features and pictures as well. Stay tuned.

Tom

Passive Solar house: The proof is in the pudding

When I last posted here the weather outside was getting pretty cold and the house I am working on still had no heat. Well we still don't have our heating system up and running yet and the house is maintaining pretty comfortable temperatures. THE LOWEST INSIDE TEMPERATURE EXPERIENCED WAS 41.9F WITH NO HEAT AND A LOW OF -4.5F

We experienced some pretty cold weather over the last few weeks and the house hasn't dropped by that much. The coldest inside temperature reached was 41.9F, that only after 3 cloudy days, highs in the lower 20's and low's at or below zero, with the lowest temp of -4.5F.
Two consecutive sunny days and the house is back up into the mid fifty's during the day and night time lows in the upper 40's. I shot some video when the temps went down to the lowest, I just haven't had the time to edit and post the vid's yet. I'll get to it soon, it is kind of tough to edit the video down to a 10min length, when I seem to be a bit long winded, I'll have to break it into 2 video's.
So, here we are in late January with no heating system installed in the house and I'm not really worried. I was early on, but once I saw how well the house performed under unusually cold conditions, I'm not worried about the pipes freezing. Hopefully the heating guy will show up tomorrow, it is starting to hold up progress on the job. Not that we need heat to work in the house but some of our finishing products need 60F heat just to work. We still have some work to finish on the inside like the interior doors and baseboard, cabinets installed, finish plumbing and the floors.
The floors are being finished with an acid stain concrete and we have been preparing them over the last few days. If you have never seen an acid stained concrete floor you might be surprised at how they look. I'll post some pictures as we complete the floors I think you will be pleasantly surprised at how warm and attractive they are. It's not just about the look, it's also about the energy. By using this finish for the floor, we add no resistance to the heat radiating from the floor. With no resistance we can lower the water temperature we need to heat the house. In turn this makes the geothermal heat pump work more efficiently and lowers the heating bill even further. This is where architectural design meets engineering in house planning, when these two work together the result is not only attractive but functional as well.

What is it that lets this house stay so warm, without heat, when it's so cold outside? There are a couple of things that are key, the insulation, the orientation, the thermal mass windows and the air sealing. Those 4 things when thought about carefully in the design phase and executed in the construction phase have enabled this house to almost heat itself. Not quite but with a very efficient heating system, maybe some solar panels and the use of geothermal energy the energy bills will be much lower than I originally expected. I originally thought the heating for this house would cost around $700 annually, but after seeing how well the house maintains without any heat, I am convinced that it will be at least 25-30% less than expected. We will see, I will be monitoring the house over the next few years and see just how much energy the house uses annually.
THE PROOF WILL BE IN THE PUDDING.

Tom Pittsley
ecobuilder@aol.com
www.eebt.org

Passive solar works, just how well we are about to find out.

No heat and we haven't frozen yet.

So, the passive solar home I am building is about to be tested by mother nature. With some of the coldest weather we have seen in several years approaching and still no heating system installed. Well, I quess you could call the Thermal mass windows a heating system.

We shall see how well the house is insulated because this is about to happen. Although we have experienced some very cold nights and days, the cold that is predicted will be 4-5 days with lows around zero and highs in the upper teens and very limited sun. How cold do you think
the temperature in this unheated house will get??
Take a quess!
I predict the lowest temperature the house will experience will be no lower the 38F. not a best case senario, but not bad for a home in New England with no heat.

I will post a video of how the house performs and lets see how well the Sturctural Insulate envelope works

Here is a video showing how well the house performed on
January 1,2009 with no heat in the house and
a night time low of 4.5F

Solar site survey: The first step to going solar and the winter Solstice is the time to do it.

While designing for solar, a solar site survey is the first step. This is the point in which you can determine just how much or little solar potential a site has. If you are considering going solar, now is the time for this survey. The winter solstice has just past and the sun is at it's lowest elevation of the year and also the shortest day of the year. ( in the northern hemisphere) No need for charts or tools, just go outside and observe how much sun reaches your home or site over the next day or two. If the sun strikes your target from 10am-2pm, at this time of the year, you have good solar potential. More is obviously better, but this is the goal you should be shooting for. If you wish to do this at any other time of the year a solar site survey is recommended. Here is a good resource for many of the tools needed to do this yourself. http://www.builditsolar.com/SiteSurvey/site_survey.htm

Don't forget about magnetic declination, this is where your compass is not pointing true north. To avoid the problems associated with declination, I prefer the solar noon method for determining true north south.

I used this during the summer and shadow cast was not as long as I had hope for. If I had done this now, during the winter solstice, the shadow cast would have been much longer. This is the best method for getting a true north/south line, all you need is the time, a long level and/or board, and the time of solar noon, the half way point between sunrise and sunset for any given day. For more accurate info check here:
http://www.srrb.noaa.gov/highlights/sunrise/sunrise.html . If you don't know your longitude and latitude, I like google earth, this allows you to zoom right in on your location and get the exact numbers.

If your thinking adding any kind of solar to your home or business, now is the time to do a quick survey to determine if solar is right for you, you may have more solar potential than you think, use all of it to your advantage. Don't forget the sun doesn't send you a bill each month and rises each day with new energy for you to harness and use.



Tom Pittsley

http://www.eebt.org/

ecobuilder@aol.com

To LEED or to lead, that is the question?

I have chosen to lead rather than LEED. For those who read this and don't know what LEED means, this is the USGBC rating system for green buildings and stands for Leadership in Energy and Environmental Design. This organization and has brought green building to the forefront and set standards for all different kinds of buildings. The guidelines they give, help people not familiar with green building, the tools needed to fully understand green building. The problem I see with the LEED system is the costs associated with it. I carefully considered having my current project rated under this system, but the cost were less than appealing. To have the home, that I am currently building rated would have cost $3,000 , just for the verification process. This does not include the time I would have to spend compiling all the paperwork involved. I concluded that, the money was better spend in improvements to the building. What does having you home rated mean anyway? I gives you bragging rights. That's it!! no big tax credit, no discounts or rebates, nothing more than bragging rights.

As for myself, I know how green this house is, the energy bills next year will speak for themselves. The money I saved by reducing the waste on the job site just makes plain good sense. Not just from the green building aspect, but makes good business sense, to save nearly $1,000 in disposal fees, let alone the amount of labor to handle all the waste.

For me green building is a lot of things rolled in to one, but it all starts with energy. No matter how environmentally friendly the products you use are, if you have to ship them half way around the world this is not green building. If they consume more energy in the production than they save in the building, this is not green building. If they are great for the environment but only last a few years, this is not green building. If working with and installing this product takes 3 times as long at 3 times the cost and adds no energy savings, this is not green. New green products are jumping onto the market on a daily basis, but you have to ask the question? What does green mean to me. We all have a different perspective on what green building means, the guidelines given by the USGBC are great to keep us all thinking in the same direction.



As for myself I chose to lead by example rather than spend money on bragging rights. The cost of building will be less and the energy bills at the end of each year will reflect the choices made. LEED if you must, but lead any way you can.

Trombe wall? Window? best of both worlds

What is it a window or a Trombe wall? Well actually it's both. This passive solar window is designed to capture and storage the suns energy in the water contained within it.

Today Nov. 17,2008 we had a daytime high temperature of 47F with a morning low of about 36F. The temperature in the house this morning was 59F with no other heat source installed as of yet. Throughout the day the window climbed in temperature reaching an afternoon high if 85F with an indoor temperature in the house rising to a comfortable 63F. It is difficult to get a good feel for the temps with the IR thermometer I am using, as it does not show the radiant heat being given of by the windows. After spending the day finishing the exterior siding it was a comfortable feeling to come in out of the cold. Most houses under construction are colder inside than they are outside at this time of the year, and never have I seen one that maintained the comfortable temperatures during construction. The geothermal heat pump will hopefully be installed within the next few weeks, but I am in no hurry to use it. If the windows continue to perform as they have over the past month and the sun continues to shine we will have very little need for any other heat source to heat this home.

Check out the video it shows just how well the window is working, and gives a good explanation as to how the windows is constructed.

Passive solar windows

Passive solar windows, that not only capture the suns energy, they store it as well. The windows shown in my previous video (sorry for the poor lighting) discribes the windows and gives some detail about how this window system is constructed and purpose behind it. The clip below shows how the windows are performing and how we are measuring the performance. Everyone that has had the opportunity to see this window is amazed that it contains 4" of water you are looking through along with 4 panes of glass. The optical clearity and beauty of the design is truly amazing. It is not often in passive solar design that we can incorporate such beauty with function, while making an architectural statement. The window shown is the first prototype of the window to leave the testing facility, were it as been under developement for several years. The design is still being worked on, as this system was installed several lessons were learned and the developer will continue to work out the details of the product. As a prototype, most the parts of the system were made by hand and the cost to do this would be very expensive. Through the testing of this window and hopefully other test sites, this product will continue to develop to point at which it will be ready for market. It is my hope that this will happen quickly, as the potential of the product to change the way that people look at passive solar energy, while saving hundreds if not thousands in energy cost along the way. I'll post more as the testing continues over the next year or more. We are installing a data logging system to keep track of the performance of the windows and that information will be posted when it is available.

Solar on Tom

Thermal Mass Windows

So, this is just my personal opinion, so take it as you may. The window system shown on the video has the potential to revolutionize passive solar design. Many water window systems have been built over the years, some with great success while others had limited results. None of the systems I have seen have had the features designed into this product. The ability to integrate this into existing homes, commercial buildings and new construction, with the appearance of beautiful window. If I didn't tell there was water in it you most likely wouldn't know it. The optical clarity of the window is astounding given that there are 4 panes of glass along with 4" of water within it. The tinting of the window is designed that the water captures a large portion of the solar energy, while reducing the glare and UV rays harmful to interior finishes and furniture. The exterior shades, not yet installed are designed to control the energy at any given time of the day, month or year. They will be motorized and controlled by a room thermostat to prevent overheating of the system, with the ability to change the room temperature with the simple setting of a thermostat. Although with the motorized shading, this is not a true passive solar system, I think it is the best of both worlds. A great mix of simple thermal mass, solar control, and beauty make this a truly revolutionary innovation in solar design. stay tuned I will be posting more videos demonstrating the performance of the system as the home is constructed, hopefully with some better lighting. When this video was shot it was raining outside. We had rain every day for the 9 days prior to the open house, some with a lot, some with a little.

But, when the day of the solar tour was held last Saturday the sun shined, although it was cold the window system heated up to 84 degrees F, the room temperature within the house was 65 degrees F, as we still have no other windows or doors on the house. The water continued to warm over the day and as the temperature dropped late in the afternoon you could feel the radiant heat coming off of the window. I don't know about you, but when the sun isn't shining and the temperature is 60 degrees, I have never felt a warm window that you could actually see through.

This product is patented by Wendell Colson

Thanks Tom Pittsley
ecobuilder@aol.com
www.eebt.org

Green Building Open House

On Saturday October 4th 2008 people across the nation will open their homes and invite strangers in to learn about Solar Energy and Green Building. This tour is hosted by various organizations throughout the country. Here in New England we are lucky to have the North East Sustainable Energy Association, the regional host for this event. http://www.nesea.org/buildings/openhouse/

I am proud to have 2 of the homes I have worked on open for the tour.

http://www.nesea.org/buildings/openhouse/googleMaps/detail.php?id=1088
Directions http://www.eebt.org/Mapto101tispaquinst.html


http://www.nesea.org/buildings/openhouse/googleMaps/detail.php?id=1222

My current project, which will be under construction at the time of the tour, allows for people to see some of the inner workings of an efficient home. The most predominant features will be Structural Insulated Panel wall system, along with our Warm Light Wall. What is a Warm Light Wall, you may ask? The WLW is a prototype window system for capturing and storing the suns energy in your window. This home will have 150 sqft of this window system installed along the south side. This is no ordinary window! The use of advanced glazing's to insulate and allow for max solar gain is just one of the elements within the window system and yes this is a window system not just a window. The exterior shading is another part of the system, which allows control of solar gains when they are not needed. By shading the exterior of the glazing, you stop about 75% of the heat which would other wise reach you window and heat you home, adding an additional burden on your cooling system during the summer months. Many solar home features large overhangs to protect the windows from exposure to the sun. While they work well in many locations, they do not allow for shading in the morning and afternoons when the sun is low in the sky. They also tend to be rather large and sometimes gaudy looking. These shades allow us to design with standard overhangs, used on thousands of homes throughout New England, after all we don't want it to look like a solar home. The main element in the window system is the water blocks used to store the suns energy. Built in a way in which they look like individual window panes, which they are, well actually two with some water in the middle. TheWLW is project under development by Wendell Colson, The vise president of research and development for Hunter Douglas. I am personally pushing for this product to come to market. I have seen the system work in their test buildings and now for the real test, THIS HOME. This will be the first installation of his latest design, and if all goes well we may all have them available in the next year or so. When I first met Wendell at the NESEA building conference I had no idea I would have the opportunity to work with him on such an incredible project. We worked together on the MIT Solar decathlon project where he generously donated the previous version of this system along with a tremendous amount of help and guidance. I personally feel that his window system could be the innovation passive solar design, that will bring it into mainstream. Saving people hundreds, if not thousands of dollars in energy costs annually. Time will tell all, and I will continue to post more information along with photos once the window is installed next week. The total system will not be in place, as the shades will need to be measured for after installation of the windows. Once completed we will be having another open house for people to come see the finished product. I hope that you can come and learn about green buildings and solar energy, if you don't live in this region there will be tours in most neighborhoods across the country for a complete list of tours from ASES click here http://www.ases.org/index.php?option=com_content&view=article&id=257&Itemid=58

` Tom Pittsley
ecobuilder@aol.com
http://www.eebt.org/

Structural Insulated Panels installation

Here is a video showing the SIP's panels being installed on the house. Sorry for no action photos, but it's kind of hard to video while lifting panels into place. One of the things which made this installation go as quickly as it did, was the prefabricating of the panels from the manufacturer. While designing the building I utilized standard panel sizes to minimize waste of materials, as well as money. 8' walls are an efficient use of the panels, as they are built as 24' panels and then cut down to size. The ceiling sections of panels were designed at 24' to use one single panel to extend from the exterior wall to the bearing wall. The less connection points used to make the panels work is always recommended, less joints equal less air leakage.

So why would you use SIP's to build with? There are several reasons, the first being the increased R-value of the wall system. The 6-1/2" SIP used for the walls of this house have an R-value of 24.5, the total R-value of the wall system is R-26. The ceiling panels have an R-value of 40. A typically constructed building using the stick frame methods would have walls with an insulation value of R-19, but that is not the true R-value of the wall. The lumber contained within the walls has an R-value of 5.5, creating a thermal bridge points within the envelope. SIP's, although they have some lumber, located for structural load points have a continuous R-value throughout the wall section. One of the other reasons for using them is the decrease in air leakage. Air leakage into a building can contribute as much as 40% of the total heating and cooling energy loss within a structure. One other reason is the ease of construction, once you become familiar with the methods of installation the system goes together easily, this is also reliant on a good design and fabrication. So the roof is going on tomorrow and the next few days as we push towards getting the building weather tight and ready for our (Warm Light Wall) system to be installed next week. Stay tuned
Tom

Passive solar home construction

So, if you have seen my previous posts and video's you will know what I have been up to, building an energy efficient passive solar home. The video link on this post is the final part of the foundation system, which was the most difficult part of the project. Many people have commented on how different the foundation looked upon casual observation. If they only knew how different this was in comparison to a traditional foundation. Here in New England we are one of the few places were people feel the need to put a basement under our homes, for most of the country the slab-on-grade foundation system is conventional construction. Of course we do have some specific requirements when it comes to insulating and heating our homes in this region. This requires a different approach to building, rather than have our foundation being an energy drain on our building we actually use it to our advantage. The thermal mass contained within the foundation allows us to use it to store the homes energy at a constant rate. Once the slab is brought to temperature the energy needed to maintain this is very low, and at a very low temperature. We will be able to heat this home with water at a temperature of 85-90 degrees F. most conventional baseboard heating systems require a water delivery temperature of 160-180 degrees F. The low delivery temperature of the heating system is the key factor that allows the geothermal heat pump to deliver all of the homes heating and cooling needs.






As I am writing this, I have already finished installing most of the Structural Insulated Panels, used for the envelope of the home. I have taken some video of this as well and will post it when time allows. The SIP's showed up on the site on Tuesday afternoon around 2pm. and by this afternoon we had just 3 gable panels to finish installing before moving on to the ceiling panels. These will be in place tomorrow or is it today? The roof framing is scheduled to start on Monday with the hope of finishing it along with some trim by the end of next week. This portion of the project will continue at a fairly fast pace as we push to prepare for a open house scheduled for October 4th.






The most exciting thing we are using in this home is a prototype window system under development by Hunter Douglas. If we have our roof shingles on the roof as scheduled these windows will be installed for the open house. This window system is in my opinion the best innovation in passive solar to be developed in recent years. It contains a very specific glazing along with glass blocks filled with water to store the suns energy and regulate how it is transmitted into the home. Not only is it functional, but very attractive as well. I will continue to post videos and pictures of the project as we move forward.

more pictures of the project http://picasaweb.google.com/TomPittsley/PassiveSolarHomeUnderConstruction#

Thanks Tom Pittsley


http://www.eebt.org/


ecobuilder@aol.com

Passive Solar construction

New Passive Solar home under construction
in Middleboro MA

Video's of the project









We have begun construction of this new energy efficient passive solar home of the future.


Designed to use the natural ability of the sun to heat the home, with an innovative thermal mass window system that is the in my opinion one of the best passive solar products to be developed in recent years. This window system will allow us to store the suns energy without overheating the space. Traditional passive solar homes had large windows with large spaces and lots of thermal mass ( concrete, stone ). When the sun was shining and the house was charging itself up with the suns energy, the spaces within the house were sometimes unbearably hot and very very bright, resulting in a space that was mostly uninhabitable for much of the day. This system will allow us to modulate the suns energy while storing it within the window system, tinting options are available to control light levels for comfort. This prototype window system has been under development by Hunter Douglas for many years and this is the first real world installation of there latest design. If you want to be one of the first to see this innovative home we will be having tours at intervals during construction. As well as being part of the NESEA's green building open house http://www.nesea.org/buildings/openhouse/ .

For more info check out www.eebt.org/passivesolar.html

Features of the house

• Passive solar orientation
• 150 sqft of specialized thermal mass south facing windows
• Geothermal heating and cooling
• Insulated slab on grade foundation with integrated radiant floor heating and cooling
• Structural Insulated Panels wall system ( SIP's ) walls R-26 ceiling R-40
• SIP's allow for minimal air infiltration, on of the largest heating losses within a home
• One floor living, making the space adaptable for handicapped accessibility
• Energy recovery ventilation system
• drop down exterior window shades along south side, for solar control
• Energy star appliances and lighting
• 1,976 sqft 4 bedrooms, 2 bath, kitchen
• Stained concrete floor through, enhancing the beauty of the house while boosting the performance of radiant floors heating system.
• Primary entrance designed as an airlock system to reduce transfer of thermal loads while heating or cooling.
• Zero Energy adaptable, the roof is designed with adequate space for PV to supply the home. Once the home is up and running for at least one year the PV system will be designed to meet the homes needs.
• Centrally located utility room to reduce plumbing and electrical runs

I have set some very high goals for this home and will be recording the performance over the course of the next few years. If my calculations are correct I expect the heating costs for this New England home to be less than $700 annually. With an anticipated total energy bill of less than $1,500 annually.

The ultimate goal for this home would be a total annual energy bill of less than $1,000 , we shall see, if this performance level is reached you would need a 5KW Pv array to meet the homes total energy demands. This is not an inexpensive option, but on worth fully exploring. The cost to convert this home to a Zero Energy home would be an additional $50,000, and would make it a Zero Carbon home as well. Stay tuned updates will be listed on my web page www.eebt.org/passivesolar.html

The goethermal horizontal ground loop is being installed Monday, I will post some pictures and video when it is done.

Thanks Tom Pittsley

ecobuilder@aol.com