Category: building

Categories
building design energy

About LEED certification

Have you ever walked into a building that has a LEED certified sticker on its door and wondered what exactly that means? Well, today I’m going to give an overview on LEED certification.

What is LEED

LEED, or Leader in Energy and Efficiency Design, is a certification program for buildings. The program was designed by the US Green Building Council (USGBC), and provides a rating system that certifies how environmentally friendly a building design is.

What can be LEED certified

The building can be certified in terms of design, construction, or operation. Neighborhoods and homes can be certified as well. In fact there are five different certifications based on the type of project:

  1. Building Design and Construction
  2. Interior Design and Construction
  3. Building Operations and Maintenance
  4. Neighborhood Development
  5. Homes

New construction, remodels and already existing buildings can LEED certified.

What is the LEED certification based on

Certification is based on the number of points that a building project earns in evaluations. Projects are scored out of 100 possible points. The points are earned across 6 categories: sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environmental quality, and innovation in design. A building that earns 40-49 points is Certified, 50-59 points is Silver, 60-79 points is Gold, ad 80+ points is Platinum.

How does a building get LEED certification

First of all, in order to be LEED certified, a building or building project needs to apply for evaluation – The USGBC isn’t just going around to all the buildings and evaluating them willy nilly, it is an opt in certification that demonstrates the owner, and the architect, designer, and construction team’s dedication to green and sustainable building. When a building project has applied for certification the team then pursues various objectives in the 6 categories in order to earn points.  Credential holders who are trained in the LEED certification categories and goals perform an evaluation of the project throughout the building process, and submit the scores for certification.

Categories
building design

Passive Water Heaters

solar water heater

The last topic I’m going to cover in this series on passive design is passive water use. Heating water consumes a considerable chunk of the energy that the typical house uses, so if you can cut your active water heating it can pay off both in terms of cutting energy use and cutting your bills.

While passive solar water heating systems are less efficient than their active counterparts, they tend to be cheaper, reliable, and long lasting. There are two basic types of passive water heaters, the integral collector-storage passive system or a thermosyphon system.

Integral Collector-Storage  (ICS) Passive Water Heater

An ICS system works best in more moderate climates, where the temperature rarely falls below freezing.  The ICS system has exposed pipes, so above freezing temperatures are necessary to keep the pipes from freezing and ruining the system.  The ICS system is made up of an insulated storage tank, a solar collection tank and the pipes that connect them. The solar collection tank is used to heat water in batches using solar energy. Once heated, the water passes into the insulated storage tank, and cool water fills the solar collection tank again.

Thermosyphon Passive Water Heater

A thermosyphon consists of a tank, pipes and a solar circulator. In this case instead of the sun heating a large tank of water, the sun heats winding pipes of water. Cool water flows from the high positioned tank into the lower circulator where it is heated. Warm water flows from the circulator back into the tank due to natural convection caused by the temperature gradient.  An indirect thermosyphon that uses glycol fluid in the circulator loop can be used in colder climates if the piping is adequately insulated.

If you’re interested in building your own passive water heater, you can find some good information here.

photo: “Solar Water Heater boiler” by gmourits CCBY

 

Categories
building design energy

Passive Cooling through Ventilation

Windcatchers near the Amir Chaqmagh Mosque Complex
“Windcatchers near the Amir Chaqmagh Mosque Complex” by reibai CC BY

Our ancestors came from hot climates, so we’ve been working on keeping the shelters we live in cool for ages.  There are a number of different ways to accomplish this, and today I’m going to write specifically about ventilation. Moving air is incredibly effective at cooling – especially at cooling people -because it helps sweat or other water evaporate. Think about it, have you ever been sweaty and stood in front of a fan? You cool off quickly, even to the point of getting a chill as the moving air evaporates your sweat.

Here are four methods of ventilation that are used around the world to help keep our homes and other buildings cool.

Cross Ventilation

Cross ventilation relies on wind moving through a space. You’re probably already familiar with the fact that if you open two windows across the room from each other, you are going to get a better breeze through a space than if you only open windows on one side of a room. Because of this, open floor plans can be great for passive cooling through ventilation. An important factor to note is that the two openings – the inlet and the outlet – should be of equal size, or the outlet should be larger for optimal air flow.

Stack Ventilation

Have you ever noticed the slated window on the top level of a house? This is a gable vent, for stack ventilation. Hot air rises and escapes through these openings. As it does so, it causes a pressure difference between indoors and outdoors, and this causes cool air to be drawn into a house through vents strategically placed near to the ground.

gable ventilation
“Untitled” by Wonderlane, CC BY

Jaali

Some Indian architecture makes use of a lattice screen called a jaali (or jali). The Jaali will often be placed lower to the ground to allow cool air to enter a room, and the lattice screen provides diffused light, while also providing privacy. They are quite beautiful as well.

jaali for ventilation
“Jaali” by Nagarjan Kandukuru, CC BY

Windcatchers

Traditional Persian architecture often makes use of a structure known as a windcatcher (other names include shish-khan, a badgir, or a malqaf). When used effectively, windcatchers are able to cool a room enough to keep water at near freezing temperatures throughout the summer months. A windcatcher is a raised tower structure, typically on the roof of a building. It may have 4 or 8 sides, and has openings on 1, all 4, or all 8 sides, depending on typical air patterns in a location.   A windcatcher can work in three different ways. It can, as it’s name suggests, catch wind and direct it downwards into a room. It can also function as a solar chimney, allowing hot air to escape, cause a pressure gradient, and pull in cool air. In a climate that has a diurnal cycle – hot days and cold nights – this is especially useful. When paired with good building materials such as adobe, a windcatcher can keep the inside of a building quite cool. Thirdly, it can be paired with an underground canal. The windcatcher will pull warm air upwards, and with properly placed inlets, pull air in along the ground-cooled water. The water will cool the air, and the now cooled air will be pulled throughout the structure.

…

Have you signed up for the building earth newsletter yet? You can do that here!

And you can follow us on facebook, pinterest, or instagram!

Categories
building design

Passive Cooling

There are a number of simple ways you can use passive design to keep your already constructed building cooler during the hot summer months, as well as some really cool building techniques that can be incorporated into construction to keep a building cool.  Today I’m going to cover the simple, already constructed building methods.

Awnings

Passive heating is all about trapping the heat from the sun inside your building. Likewise, passive cooling is about keeping that heat out. In the posts about passive lighting and passive heating, I talked about how important southern facing windows are to letting light and heat into a building, but what do you do with those windows during the summer? Using an awning on your southern windows can be a great solution. The angle of the awning will keep out the harsher rays of the sun in the summer, and in the winter, when the sun is angled lower in the sky, the light and heat will still be able to come in under the awning.

Shade Trees

Planting a deciduous shade tree in your southern yard can help keep your home or building cool as well. In the summer months, the leafy tree will provide shade for your southern windows, and if the tree is tall enough, for the roof as well.  In the winter, the tree will drop its leaves and let the light and heat pass through.

Curtains

Using thick curtains on southern and western facing window during the day can also keep keep a room or building cool by keeping the sun out, in the evening when the harshness of the rays have lessened, you can open the curtains again to let in the light.

Air Flow

Get that air moving. Open up windows on all sides of the building, and keep interior doors open as well to help allow the air to pass through the building.

Next week I’ll get into some of the ways that we can use construction to help get the air moving, and keep it cool in the first place.

…

Are you looking for an introduction to passive design? You can find it here.

Oh, hey, Building Earth has a facebook page now.  Keep up to date on posts and other interesting green news by liking us!

Categories
building design

Passive Heating do-it-now

Ok, maybe you don’t have any big renovations planned for your home, but you still want to make your living space more heat energy efficient. Let’s go back to the second goal in passive heating:  Seal up your building so the heat doesn’t escape. Here are some simple things you can do to seal up your home and keep it warm without burning so much gas this winter.

Caulk

The thing about warm air is that it can escape through really tiny holes and cracks, so we want to do our best to fill them all in. Start by checking your windows, where the frame of the window comes in contact with the wooden sill. Is it sealed? If not, use caulk all the way around to fill in and block any potential leaks. Now look at the junction between the glass and the window frame and do the same. You can find clear caulk especially made for windows for this project.

Window Plastic

To add an extra layer of sealant, (or if you live in an apartment and can’t get permission to caulk your windows,) go with the old standby of window plastic. Wipe down the sill well, and make sure it is dry before putting down the double sided tape to help ensure a good seal.

Weather Stripping

Doors are the other prime leak location. Especially older wooden doors whose wood has begun to weather and warp. You can help stop up those possible leaks by putting weather stripping on the edges of the door. A draft guard along the bottom edge works well to block leaks too. Make sure you measure your door and the gaps between the door and the jam to ensure you get the appropriate size weather stripping and draft guard. You want the weather stripping to be slightly thicker than the gap it is filling to get a good seal. So there you have it, three simple ways to make your house better at passive heating. The great news is, these three things can also help keep your house cool during the summer as well. And we’ll have more on that coming up.

This post contains affiliate links.

…

Are you looking for an introduction to passive design? You can find it here.

Oh, hey, Building Earth has a facebook page now.  Keep up to date on posts and other interesting green news by liking us!

 

Categories
building design energy

Pre-construction passive heating

passive heating

Since my post on passive lighting got a little unwieldy (900+ words! Who has time for that?) I decided to break this post in two in hopes of avoiding another monster post. So today I’ll be covering passive heating from the perspective of what should be done before or during construction of a building.

I know, I know, it’s the beginning of July, and probably the last thing you want to think about is keeping your house warm. But it might be better to think about this sort of thing now than in the middle of January when you open your heating bill. In fact, you might still be recovering from the number those polar vortex heating bills did on your budget this past winter. So I propose that it’s always a good time to think about how you can more efficiently (and cost effectively!) heat your home.

Passive heating ultimately comes down to two goals:

  1. Capture heat from the sun.
  2. Seal up your building so the heat doesn’t escape.

Just like with passive lighting, before construction begins is the best time to start thinking about passive heating. Some forethought on position and building materials can save all sorts of heat energy down the line.

Siting

The goal when siting a building for passive heating is to put the broad side of the building in direct sunlight. Here in the northern hemisphere, that means the south side of the building should be the broadest side. The west side is also a good choice because the afternoon sun is stronger and hotter than the morning sun.

Windows, Walls, and Floors, oh my

So, now that you’ve set up the position of your building to soak up the sun, you need to get that heat from the outside in. This can be done by putting nice big windows on the sunny side of your building. Some types of window glass are better at allowing heat to pass through them than others. For passive heating, look for a solar heat gain coefficient (SHGC) of 0.6 or higher.

And once the heat is inside, you want to hold it there. Flooring and wall materials such as concrete and tile are great at holding onto heat (this is called a solar mass). So put a tile flour under your big southern window.  And build that southern wall with bricks or concrete blocks.

Side note: In our neighborhood in Detroit, we often saw that flowers planted beside a brick building were among the first to pop up in the spring – the bricks held onto enough solar heat to convince those seeds to germinate a bit earlier!

Insulation

Insulate. Insulate. Insulate.

Insulate more than the minimum recommendation. Insulate on the outside of the thermal mass (because you want to keep that heat inside!). Remember, heat rises and wants to dissipate into cold air, so insulate your roof especially well, and your north wall too.

So there you have it, three main areas of consideration when it comes to construction and passive heating. If you’re planning on getting your house re-roofed this summer, take some extra time to check the quality of your roof insulation, and add some more!

…

Are you looking for an introduction to passive design? You can find it here.

Oh, hey, Building Earth has a facebook page now.  Keep up to date on posts and other interesting green news by liking us!

Categories
apartment living building design energy

Passive Design for Lighting

One immediate way that we can cut our CO2 emissions is to just use less energy. Since our homes and other buildings are huge energy users they are good places to start. By using passive design practices, we can build and maintain more energy efficient homes by using energy from the sun or the ground instead of energy from the grid to serve our needs.

Natural Light and Proper Siting

Using the sun to provide most of our light can reduce the amount of electricity we use and can save money – both on our electric bill and in the cost of light bulbs.

The best time to think about using natural light in place of electric light is before construction. At this point, thinking about window placement can provide a building with adequate light for much of the day. In the summertime, well placed windows and an open floor plan can provide for plenty of light well into the evening hours.

To this end, siting a house properly can be very effective in providing natural light. We often think that the face of a house must be parallel to the street, but depending on the direction that the street runs, this may not be the best position for the windows and the walls. Taking into account the cardinal directions and the angle of the sun throughout the year can help determine the optimal position of windows to take advantage of natural light.

Continuing in this vein, thinking about the layout of the rooms in relation to how and when they will be used during the day before building can help optimize the use of natural light in a structure after it is built.

South facing windows

South facing windows are the workhorse of passive lighting in the northern hemisphere (in the southern hemisphere it would be north facing windows). Because of the tilt of the earth’s axis, in the northern hemisphere the sun is angled to the south. A south facing window, then, receives light throughout the whole day, not just in the morning or evening. South facing windows are put to best use in rooms that will be used all day long.

East facing windows

East facing windows receive the strongest light in the morning, and thus are best positioned in rooms that are primarily used in the morning through late afternoon, such as an office. If you are an early riser, you may prefer to have east facing windows in your bedroom. However you may not want east facing windows in a nursery if your baby wakes with the sun, or in your bedroom if you prefer to snooze a bit later in the morning or work the night shift.

West facing windows

West facing window are pretty much the opposite of east facing windows when it comes to lighting. (I’ll get into the differences in the heating and cooling sections of this series.) They are best positioned in rooms that are used in the evening, as they will provide the most light during the later part of the day. I do a lot of cooking in the evening, so I prefer to have a kitchen with western facing windows.

North facing windows

Due to the earth’s tilt, northern facing windows will receive the least amount of sunlight, and thus are useful in rooms that are used primarly during the middle of the day, or in rooms that are meant to be kept darker. An office might be the right choice for a room with north facing windows. Or maybe this means that depending on your sleep habits and preferences, north facing windows would work well in your bedroom. If you are building a basement cellar and your basement has windows on all four sides, choosing the north wall to build your cellar against makes the most sense.

Skylights

Skylights can go a long way to lighting a room in the middle of a house. Depending on the direction they are positioned, the pitch of the roof they are installed in, and how far north or south the building is, they will provide different amounts of light during the day or evening.

So directionality and placement of windows is something that can be considered before a structure is built, but afterwards can be quite costly to change. Here are a couple examples of what can be done to improve passive lighting in your already built home or business:

Curtains

Using sheer and light colored curtains during the day can allow light into a room while still providing a bit of privacy. They can also help temper the strong rays of a rising or setting sun on east and west facing windows.

Mirrors

Well placed mirrors can help spread light into darker areas of a room or into a windowless hallway.

Wall paint

Light colored paint will reflect more light around the room, whereas darker colors will absorb more light. So if you are partial to bold wall color but don’t want to greatly reduce your ability to use passive lighting, put the color in a room with south facing windows or with windows on multiple sides. Dark and light colored flooring can be used to the same effect.

…

Are you looking for an introduction to passive design? You can find it here.

Oh, hey, Building Earth has a facebook page now.  Keep up to date on posts and other interesting green news by liking us!

Categories
building design energy

An introduction to energy efficiency through passive design

The building industry uses about 75% of electricity production in the US. This means that if we can make our building-related-energy-use more efficient we can make a big dent in the amount of electricity that we need to produce, and thus make a dent in the amount of greenhouse gas emissions we are releasing into the atmosphere by burning coal and natural gas to make electricity.

Energy efficiency in our homes can come a few different forms, but for the next few weeks I will be focusing specifically on energy efficiency through passive design. To start, let’s break it down. Energy efficiency means using less energy to achieve the same ends. In terms of buildings, I am going to focus on are lighting, heating, cooling, and water use efficiency. Passive design is when a building is built in a certain way so that you don’t have to use energy to save energy. For example, using sunlight to light a room is a passive design element because the sun is already there. You don’t have to add any energy into the system (the building) to produce light. Using an LED light bulb to provide light is an active design element because, while you are using much less energy than a filament bulb or CFL, you are still adding energy to light the room with the LED.

As you might guess, the best time to incorporate passive design elements into a building is before it’s even built. But there are some things you can do to an already existing structure to make it more energy efficient through passive design. I’ll be sure to cover both areas as this series continues.

As always, if you have any questions up front about passive design, send them my way and I’ll do my best to answer them as we go.

…

Oh, hey, Building Earth has a facebook page now.  Keep up to date on posts and other interesting green news by liking us!