Subscribe to the feed Get updates via e-mail

Archive for the ‘Renewable Energy’ Category

The Grande Finale – an Energy Audit & HERS Score

Monday, October 26th, 2009

My friend, Alva Morrison, has been in the weatherization industry for many years, working for the state of NM helping families in need tighten up their homes with insulation, caulking and funding. As energy audits got popular for the general public, his natural next step was to become an Energy Rater. Special training and equipment is needed for this job, which entails sealing up a house, running air through it, analyzing air leakage through computer software and offering recommendations.

When my construction was done, Alva and I decided to do an energy audit. Instead of guesswork, I wanted documentation of my energy savings were and how I could make improvements to further save.

A blower door test determines energy usage. Alva determined the volume of the house, then we talked about construction details. He plugged that information into his software, then we sealed up the windows and exterior doors, leaving the interior doors open for maximum air flow.

He installed the blower in the kitchen door. blower door_3631 The red canvas was sealed all the way around to make the door air-tight. The blower was plugged into his laptop, then turned on to create air movement, which was registered in the software. We looked for areas where air was coming in. Alva caulked a few old window frames, and rechecked the figures.

We were surprised at some of the results and recommendations. Here are his comments:

“Nan’s house is a great example of what can be done to turn a pretty average house, built to code a couple of decades ago, into a modern energy-efficient home. If built as is today, it would exceed qualification for the USEPA Energy Star certification, even though many of the walls still have 2×4 insulation in a 2×6 wall. The main factor driving the house’s lean performance is a thick blanket of attic insulation. But the solar hot water and the balmy sunroom, with a thick adobe wall to catch and hold the heat, provide solid backing. Add to that a refrigerator, which squeezes kilowatts until they scream, and you have a working person’s house to take us all through the next century of global warming both economically and comfortably. All these things were added to the house by Nan at moderate expense.

“Analyzing possible improvements was very interesting. Tearing off sheetrock and re-insulating the walls seemed like it should be a no-brainer. But when we ran it through the computer, it only showed a savings of around $25 a year- not much reward for all that trouble. The moral is, heat goes up, not sideways.

“However, we found another weaker spot in the building’s ‘heating envelope’: the uninsulated foundation. A quick rework of the house through the energy rating software showed that digging a barrier of four inch rigid foam in around the perimeter of the foundation would return $175 a year – and that?s if the cost of wood and gas stays the same (don’t hold your breath for that!). Get out your shovel, Nan!”

As you can see, an energy audit gives you a lot of information on how to improve your home. I had him calculate a HERS (Home Energy Rating System) score, because I wanted to be able to show others the entire process.

The number of a HERS score is based on the International Energy Conservation Code (IECC), which is 100. My score was 88, meaning my house is 12% more efficient than the code. The lower your number, the more efficient your home is. When I make improvements, Alva can plug that information into his software, re-analyze the results and give me new recommendations

Many municipalities, including Taos, are beginning to require HERS scores on new construction. I highly recommend an audit, and, speaking as a RealtorR, I use them as effective marketing tools for homes. Buyers can see current efficiency and how it can be improved. There are fewer surprises and disappointments after purchase.

Food has been coming out of the greenhouse year-round. Due to some unanticipated condensation problems and failing flashing around one skylight, the greenhouse is not in full use. There is no soil in the bed yet, but I have been successfully growing in containers. This picture is my tomato garden on Jan 31, 2009. Once the construction issues are resolved, I will have achieved my goal of a true food-and-heat-producing solar greenhouse.

Find a certified local Energy Rater through RESNET – Residential Services Energy Network http://www.resnet.us

The entire remodel with more details and pictures is on my website: Solar Retrofit 2007 http://www.nanfischer.com/remodel1.html

Reblog this post [with Zemanta]

Solar Thermal – Hot Water for Domestic Use

Monday, October 19th, 2009

My mom passed away in 2006, and her estate was finally settled in 2007. I had no idea what my brother and I would inherit, and from what the attorney, stockbroker and CPA said, it sounded meager. I was thrilled to find a check in my mailbox that would get me started on my remodel! Meager to a big-wig, perhaps, but abundant to someone living simply.

The first thing I looked into was solar thermal – hot water from the sun for domestic use. From www.energysavers.gov:

Solar water heaters – also called solar domestic hot water systems – can be a cost-effective way to generate hot water for your home. They can be used in any climate, and the fuel they use, sunshine, is free.

Solar water heating systems include storage tanks and solar collectors. There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don’t.

Most solar water heaters require a well-insulated storage tank. Solar storage tanks have an additional outlet and inlet connected to and from the collector. In two-tank systems, the solar water heater preheats water before it enters the conventional water heater. In one-tank systems, the back-up heater is combined with the solar storage in one tank.

solar dom hot water

After much research, like that above, I called a solar installer, Valverde Energy. The owner, Larry Mapes, came out to the house to do an assessment. We first talked about my current and future water use. My two teenage daughters were going to fly the coop in the next few years, so water usage would dwindle. All those long, hot showers, mounds of laundry and constant dirty dishes would be a thing of the past when I settled back into living alone as I had done before having children.

So instead of creating a system for a family of three, which would be big and inefficient just for me later on, we decided on a smaller system that would be adequate for all three of us, and would rely on very little natural gas back-up as our numbers shrank. This smaller system could be expanded when the house is sold and another family moves in.

Once we’d made that decision, we talked about infrastructure. This isn’t very exciting and is nothing anyone sees, but it was necessary to get it done.

I am on a shared well with three other homes. For years, we have talked about putting in new water lines, but not everyone had the money at the same time, and our bank account wouldn’t cover it all. I went ahead and replaced the aging line to my house. The stub-in had to go in a certain place to accommodate the solar system, since I was moving the hot water heater as well.

Larry suggested tapping into the natural gas line in the new road adjacent to my property. My gas supply was currently propane, which is more expensive, and he said this alone would cut my energy bills. It didn’t take much to persuade me to switch! The water line came in from the south, and the gas line came in from the north. My yard was chewed up all the way around! Ah… remodeling…

stubins_3428 The infrastructure upgrades needed to be done first, because those utility lines had to be in place for Larry’s crew to install the solar system and before we could pour a slab for the greenhouse. We joked that most women don’t care about these kinds of things in a home, because you can’t decorate them, but I was excited about the value of what he was proposing.

I quietly thanked my mom for making this possible. 515

More info on:

Solar hot water http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12850

Valverde Energy http://www.valverdeenergy.com/

Greening up the House with Energy Efficient Windows

Monday, October 12th, 2009

Once the infrastructure decisions were finalized, Alex, the construction contractor, and I could firm up our plans. We knew where water and gas lines could go in the house and greenhouse.

Not only did I plan on the greenhouse addition, but I also made some drastic changes in the rest of the house.

1) I replaced all my single pane windows and sliding glass door with vinyl, double pane, energy efficient, low-e windows.

It’s important to choose the right windows for different areas of a home. Lighting, vies and orientation are taken into consideration.

window There are several criteria to determine a window’s performance, two of which are:

  • Solar Heat Gain Coefficient (SHGC) – the higher the number, the more heat the window transmits.
  • U-factor rating of the National Fenestration Rating Council (NFRC) – the lower the number, the more efficient the window, based on the glass, frame and spacer material.

I have big pictures windows and a slider on the northeast side facing the mountains. Sun pours in here on summer mornings, so I chose windows with a low SHGC that let in sun and but heat. Obviously, on the southwest side, that’s not what I wanted, so I chose windows with a high SHGC that allowed the sun to heat the space.

Low-e stands for low-emissivity. There is an invisible, thin coating on the glass that controls the amount of heat moving through it and affects the SHGC and the U-factor. All windows should be labeled with this information.

2) I changed the floor plan in western 2/3 of the house to facilitate heating, which was difficult due to a remodel done by a previous owner. The traffic flow was choppy, which also prevented heat from being distributed evenly. I was spot-heating separate areas, which was a continual experiment and not very effective. If I could easily get the rooms heated, I would further reduce my energy bills.

3) I created two separate heating zones:

  • The greenhouse, girls bedrooms, a bathroom
  • The kitchen/living room, my room, a bathroom

Do you remember that huge room where I installed that huge sunny window previously? I split it in two and gave the girls identical rooms. The doors, which I recycled from other parts of the house, opened into the greenhouse, which would help heat them and the second bathroom. This area was separated from the kitchen/living area by a steel exterior door.

remodelimg_3550 4) I added insulation in the ceiling over the kitchen/living part of the house. Since we put gas lines in the attic and access panels in the ceiling, we got a chance to look at the insulation. It was pretty thin, and we had disturbed a lot of it with our work. I decided to beef it up by having R30 shredded fiberglass blown in on top of what we guessed to be about R19 insulation. I was eager to see how my heating bills would react.

My original thought for the greenhouse was to create a 5.5′ wide passive solar hallway to the girls’ new rooms and bathroom. This would span the entire front of the space. After many measurements and number crunching, we decided to fill the entire corner with the greenhouse. It would be easier for Alex to build if we brought the exterior wall out even with the existing wall. This space was 8.5′ wide and allowed the planting bed to be included.

Once we had these dimensions, we could create a detailed design and start ordering materials.

More on energy efficient windows:

http://www.energysavers.gov/your_home/windows_doors_skylights/index.cfm/mytopic=13320

Reblog this post [with Zemanta]

The Solar Greenhouse Gets Built

Monday, October 5th, 2009

I will spare you the entire thought and building processes and show you what we finally decided on.

remodelimg_3285 Since this is southwest orientation, my main concern was getting extra light and heat, since the winter sun does not come around to that side until late morning. I put three fixed skylights along the lowest part of the ceiling, which has worked well. The sun comes through them a few hours before it gets to the front.

In the New Hampshire house, the south facing windows were floor-to-ceiling. I wanted as much sun coming in as possible for daytime heating. Here in Taos, I wanted a planting bed close to the windows for maximum light, so the windows are in the 5′ space above the 3′ deep planting bed. In both instances there is a 1′ spacer between them for support.

Ventilation is as important as heating. Plants and people don’t like temperatures that are too hot, as much as they don’t like them cold. To keep everyone and everything comfortable, I installed:

  • A glass door flanked by two double-hung windows. This allows more sun in winter and serves double duty to ventilate in summer.
  • Two double-hung windows in the end wall
  • Two VeluxR operable skylights in the upper part of the ceiling. This is where heat will rise, which made it the most logical place for a moveable vent. Air moves in through the windows carrying the heat out of the top vents. Moving air is cool air, so opening the windows and the vents cools off the greenhouse, even if it is hot outside.

The soil in the bed is to be part of the thermal mass. It will absorb the sun’s heat to keep the temperature levels even and keep the plants warm. The concrete floor and an adobe-lined wall on the northern side are also mass that will absorb sun and ambient heat to radiate back out at night.?remodelimg_3526

The ceiling is super insulated, and exterior doors lead into the four rooms of the house. There is no supplemental heat in the greenhouse. In the event there are many cloudy days in a row or old-timey winter temperatures of 40 below, I will sacrifice the plants as the greenhouse gets cold, but the heat in the other rooms will not be lost. The girls have small gas heaters in their rooms for the coldest days and nights.

remodelimg_3531 The work was done enough by Thanksgiving to start seeing the benefits. My fuel bills that following winter were half of what I’d been used to paying. I cut my wood consumption by half with the new ceiling insulation and double pane windows, and my natural gas bill was about $40 a month at it’s peak with the girls using their heaters.

Come spring, I got an energy audit and a surprisingly good HERS (Home Energy Rating System) score.?remodel.gh.1.09_3880

Solar Greenhouse – Detached or Attached?

Tuesday, September 29th, 2009

When I bought my house, it was an upside-down T, with the stem facing southwest. In last week’s post, I talked about installing sunny windows in the southeast and southwest walls for passive solar daytime heating. Now I was trying to decide how to further remodel for more solar gain.

floorplan before

I could have added a greenhouse on the southeast corner adjacent to the kitchen. This was very appealing as far as harvesting food and herbs. I’d also envisioned it as a sitting area, the breakfast nook, I suppose. But I enjoyed the new windows, and one was in my bedroom. I’d have missed that if it went into a greenhouse instead of to the moon, trees and coyotes.

The warmest winter sun hit the southwest corner, so I decided to add something there. I wasn’t sure what, but many pencils and eraser goobers later, I came up with this plan. Craig Simmons of Eco Builders fleshed out the details for me.

I was content enough with the heat produced through the new windows that I put these drawings away. I was also a working single mom of two young girls, and my time constraints prevented me from doing a lot of research into this project, never mind starting and completing it! I rolled up the drawings and propped them up on my desk.floorplan after

In 1997, I lived in an old block home on an irrigated acre of land in Ojo Caliente – almost the adobe dream home! I was more interested in the land than the house, and we cultivated half of it with beans, corn, tomatoes, squash, herbs and flowers that we sold to friends and co-workers.

Out near the garden, there was a small frame greenhouse with translucent polycarbonate walls. I checked the overnight temperature in early spring to see if I could start my seeds in it. It was too cold, since it was not heated or insulated. It was essentially a cold frame with an 8-foot ceiling and roof.

I started researching greenhouses and was disappointed to find all standard greenhouses need supplemental heat. This is usually generated with electric heaters for something as small as I was looking at. Aside from growing food to eat healthy, cost needs to be taken into consideration. Heating a non-insulated building of plastic walls with electricity was not cost-effective.

UdgarPujaWinterDome (2) I came across the Growing DomeR Greenhouse in a gardening magazine. It is still available, and I see them popping up across the landscape as food and energy costs rise. This is a passive solar, geodesic design with glazing on the south side and insulated solid walls on the north side. Planting beds and the concrete slab floor are the thermal mass, along with a pond. Do you remember the 55-gallon drums in the solar pods? Poisson knew water is one of the best materials for thermal mass. It must be sized properly so it can radiate heat effectively. The pond can hold fish or water plants, or boards can be placed across it to make more room for container plants.

The combination of masses in this greenhouse meant no supplemental heat. It was an environment that took care of itself – an ecosystem of sorts. I was sold on it immediately!

For a variety of reasons, though, I didn’t purchase one at the time, but this is the only greenhouse I recommend to anyone. It needs no extra heat, and the larger ones double as a small living space as well.

Ten years later, it is spring 2007, and I want to start my vegetables from seed. I am toying with the idea of buying a 12′ diameter dome greenhouse and putting it about 100′ from the house down the hill on my property. This is a sweet, quiet, sunny spot with completely different views and feel than the house. A few cottonwoods along the irrigation ditch give the space a cozy feel and summer shade. A passive solar greenhouse here would be an excellent get-away.

As I walked the land, I began to picture it. I imagined bringing in electricity and water, and building a path of crusher fines between the greenhouse, the house and the garden. I considered views, sun, neighbors and the heat the greenhouse would produce. I wanted to somehow move the extra heat back up to the house in winter. I thought of underground ductwork, insulation, fans….. My little greenhouse project was getting complicated, the kind a contractor would balk at.

In a split second, like the cartoon cliche of a light bulb going off over your head, my face went from bewilderment to wonderment and glee! I decided to build an attached passive solar greenhouse for heat and food. Remember the mention of this book??yanda.fisher.4153

I dusted off my original vision and the drawings Craig and I had worked on a few years before.

More info about:

Growing DomeR Greenhouse http://www.geodesic-greenhouse-kits.com/

Craig Simmons, Eco Builders http://www.ecobuilderstaos.com/

Reblog this post [with Zemanta]