Energy Efficiency

Solar Thermal is the use of the suns energy to heat water or some other fluid. The heated fluid is then used to preheat domestic hot water, in-floor or in-slab heat. Excess heat generated from these types of system can also be a challenge in that there may be no need and or use for this energy at time of collection. By using a system like this in conjunction with heat sync we can defer use until needed. Collection of solar related energies happens during the day while for the most part our need for energy happens at night. Consequently heat syncs are a vital component to the overall efficiency of these types of systems.

Heat sync large mass of dense material that essentially holds heat for later use when required. Large boulders, concrete, water; all can be used as mediums to store heat.

Photo Voltaic (pv) Panels

Electric energy creating panels placed on or near the building. The energy created is direct current and requires an inverter to change the output electrical energy to a more common and usable alternating current.

Roof Mount

PV panels can be placed on the roof of most structures. The optimal angle of which usually correlates to the building sites latitude. I.e. For Calgary the optimal panel angle is approximately 51 degrees from the horizontal.

Wall Mount

Certain types of pv panel can be wall mounted. These panels are typically not as efficient but are very useful in locations where architectural controls, or overshadowing issue do not allow for conventional panel to be placed on the roof system.

Solar Array

Solar arrays are rack mounted pv panels that have the added benefit of being able to rotate (or follow) the suns path at an optimal angle for a greater period of time. These systems are large and are usually associated this acreage type residential developments or more commonly commercial solar farms.

Geo-Thermal

The use of the earths core temperature as a heat sync. At approximately 200 ft the earths core temp is pretty consistent (generally). This temp is approximately 7 degrees Celsius. By drilling bore holes into the earth (appropriately spaced) we can extract a constant fluid temperature, we then pass this fluids heat by way of a heat exchanger on to another fluid that happens to boil at approximately 5 degrees Celsius. The result is the phase change of the second fluid from a liquid to a gas. That gas is the compressed to force it to “give off energy” and in essence force it to again change phase back to a liquid. We can then harness that energy and use it to heat domestic hot water, in-slab and in-floor heat, power fan coils, etc. All without the need for fossil fuels. The second liquid is the passes through the heat exchanger again and super cools the first liquid to a temperature well below it original 7 degrees Celsius. This fluid is then run back down the bore holes to be “warmed” by the earth to is required 7 degrees again and start the entire process again. Geothermal systems can be closed loop (as described here) and can also be used open loop, as well as into large bodies of water (one who’s temperature is not easily modified).

Poor Mans Air Conditioning

Geothermal systems can also be run backwards in the summer time, effectively drawing the cool temperatures of the earth’s core (in comparison to the at grade air temperature) to aid in the cooling of living spaces.

Building Envelope

Air Exchanges Per Hour

In an effort to increase efficiency, builders are attempting to have a greater control on the air changes (of a building) per hour. This effort is to attempt to control the amount of energy (in the form of conditioned air (heated or cooled)) from escaping from the building. This would be a considerable savings on heating and cooling loads over the annual operation of the building. To accomplish this we would need as tight an envelope as possible.

Heat Recovery Ventilators (HRV’s)

Heat recovery ventilators take the conditioned stale indoor exhaust air and pass it by the fresh unconditioned intake air prior to conditioning it, while keeping a physical separation between the two. This allows builders a much greater control of the indoor air quality of the home, while also maintaining the energy efficiency as well.

Vapor Barrier Design Options

Spray Foam Insulation

Conventional wood frame construction with conventional vapor and moisture barriers are a considerable challenge to get the ac/h down to the targets listed above. Newer spray foam insulations have come along I the last couple of years that have solved some of these issues. These types of insulation act as an insulation as well as the vapor and air barriers all with one (all be it more expensive) material. While this material is not a cure all for insulation challenges, for builders looking to greatly increase both insulation value and air tightness, it is an excellent place to start. Most good spray foams are now soybean based from a chemical makeup to unsure that no unnecessarily harmful chemicals are added to the indoor air quality.

Exterior Vapor Barrier

Builders who prefer conventional wood frame construction and batt insulation techniques have started to us exteriorly applied vapor barrier systems. While this great simplifies the installation of the system it also must now be installed perfectly and protected from damage after installation.

Passive Solar Design

The concept of using the suns energy in conjunction with building design, and site orientation, to heat and even cool the living environment. Some techniques relating to this would be high thermal mass elements to store this energy for later use.

Passive Solar Heating

The use of the suns energy to heat building elements, preferably ones with a high thermal mass. Elements with a high thermal mass would be tile, concrete, water. When high thermal mass objects are heated, they no not immediately begin to give off that heat but rather absorb the energy until much later. This delay coincides a lot of times with the nightfall.

Passive Solar Cooling

To use the heat of the sun to cool a building we must design what is know a heat stack. This is a vertical volume of space that is higher in elevation than most of the living spaces in the home. By allowing sunlight to penetrate this space and by giving it a dark coloration, we can allow the hot air of the home to rise from and into this space venting to the exterior. This also creates a negative air pressure that we can also use to infiltrate cooler fresh air.

Trombe Walls

Trombe walls are a variation on the vertical stack concept except these walls are constructed behind a single pane glass wall with a small 2-4 inch air space in front of a dork colored heating wall. By allowing the suns energy to easily penetrate the glass and heat the dark surface a considerable amount heat can be gathered and with the addition of vent holes top and bottom, and allowing natural convection to distribute the warm air.

Thermal Massing

The use of high-density materials as primary building elements for the purpose of storing warmth and coolth to offset exterior (unconditioned) air temperatures. In summer, high thermal mass materials will remain cool in comparison to air temperatures, thus greatly reducing the need for mechanical cooling. The same is true for winter, we allow the suns energy strike these thermal mass elements and store its energy. By comparison to the conditioned air temperature the high mass objects are considerable warmer, give off their heat, and thus reduce the need for additional mechanical heating.

Earth Tube

A concept of using the earths natural temperature to preheat or pre-cool intake air there buy reducing the heating and cool loads on the mechanical systems. The air intake is placed at a distance from the house. The intake is then taken down vertically to a depth (below frost level), it then travels horizontally toward the house and enters the home below grade. The concept being that when outdoor air temperature is cold (winter) the ground temperature is considerably warmer (-40 degree air temp. To plus 2-degree ground temp) thus dragging the air through this “tube” preheats the intake air and reduces heating loads. The inverse is true in summer when outdoor air is warm and ground temps are relatively cool. Also referred to as a poor mans air-conditioning.

Construction Details

ICF (insulated concrete forms)

Insulated concrete forms are a modern concrete form that incorporates styrofoam insulation as the concrete forming medium. This reduces waste by not requiring a wood forming system. The system itself is very efficient and has very little waste associated with it and leaves behind a considerable more efficient foundation wall than conventional 8” concrete walls. This system is more expensive and time consuming but has a good return on investment that will be realized over the life of the building.

Reduced or Eliminate Thermal Bridging

Thermal bridging is predominantly related to conventional wood frame construction. It has to do with the nature of wood framing (2×6 studs touch the inside drywall and the outside sheathing). Wood studs are not an insulative material and can in extreme weather condition pose a problem allowing heat to “bridge” across the studs.

Staggered Stud Exterior Wall Construction

One option to reduce thermal bridging is to replace the conventional 2×6 exterior studs with two staggered sets of 2×4 stud on a 2×6 top and bottom plates. This allows the “missing” two inches of stud to be filled with insulation, and while still not receiving the full value for the insulation added, it does virtually eliminate the bridging effect of the studs.

3 Stud Corners

This framing technique is a modern way of framing that allows for greater and more consistent insulation to be added to the corners of buildings. Corners are one of the greatest bridges of heat energy in the modern home.

Creative Ducting

How we move, distribute and gather air in a home greatly affects the efficiency of the heating system.

Air returns Placed at Natural/ Humid Locations

Bathrooms

By gathering warm moist air from bathrooms we can maintain our desired humidity level and use the already heated air to preheat our fresh intake air.

Behind Refrigerator

Behind the refrigerator is an interesting location to gather air. This location is one of the hottest in the house because of the nature of the refrigerator to give off a great deal of heat. Using this air to preheat fresh air is very economical.

Durability

Durability relates to the unnecessary waste of replacing substandard building materials with similar materials or even with the materials hat should have been used to begin with. More reliable systems and materials building science have established a good number of advanced techniques and materials that will increase durability and system function. The implementations of these are at the discretion of the builder. Most have been staying with what they know.

Health

With the increased effort towards tightening the building envelope. We must now begin to concentrate on the materials that are placed inside the home. To ensure that we build a safe and healthy home, the use of glues, paints, adhesives and binders must be carefully selected.

Material Selection

Hard surface selections like hardwood instead of carpet greatly improve the indoor air quality of a home. Granite counters instead of laminates. Granite is more durable and is a more sterile surface for food preparation. Green back carpets if needed should be specified. True no voc paints. Plywood’s and mdf board that is formaldehyde and voc free.

Conservation

Water

Rain Water Collection

The use of design concepts and material choices to facilitate rainwater collection for reuse. Water must be filtered to remove small medium and large particulates as well as microbial content to allow for storage in above or below grade cisterns. This water is used primarily for irrigation, and is generally not brought into the house for domestic water reuse.

Grey Water Collection

The practice of reusing domestic water to flush toilets. Requires extra plumbing to enable laundry, kitchen sink, shower, and bathroom sink water to be redirected to a grey water tank system. Typically this is a two-tank system the first being a holding tank. This tank would then get connected to a filtration system to filter out particles and a uv light filter to kill any water born microbes. This would then lead to the storage tank for on demand use in the toilets. Grey water systems are also used for irrigation but are seasonal in nature and typically the water does not go through the same series of filters as it is just piped directly to the exterior and into the flower beds via drip lines. Low flow appliances, faucets and toilets

Design Alternatives

Enabling homeowners to be greener

Built in recycling centers

Built in composting options

Universal design options

Design House to Grow With Family

This concept is based around the idea that we don’t move to find a home that fits our needs but rather we design and build a home from scratch that is healthy and durable in a community that is close to mass transit and or close to where we work. And the build in some inherent flexibility into the design that will allow us with the simplest of efforts to change the function of a room or two to accommodate a change in life or family make up.

Inherent Design Flexibility

Movable Walls by building the structure in such a way as to eliminate interior structural walls and clear span the living spaces (not that hard or expensive to lear span up to 40’ now). We the intelligently place our pluming locations (that could still be moved later if need be) and design an open concept plan with a minimum of walls that would be temporarily fixed in place. If we needed to move them we would just undo some bolts, lift them out of place, place them where we want them and bolt them back down. This is the same concept being used right now by a Calgary firm (DIRTT) that specializes in office partitioning systems. You could even change the look of the walls to change up the interior feel of the space or the entire house.

Clear Span Concrete

Open webbed metal joists while not the most environmental product in and of themselves could be used in this application to achieve this sort of design flexibility. And while concrete itself is not looked upon as an environmentally friendly material it is not hard to agree that it’s durability and prevalence in the marketplace is unparalleled. And if the customer was a more forward thinking (modern architecture lover) the open webbed joists and visible mechanical, electrical and structural elements could be viewed as a design choice, not a cost cutting and design flexibility option.

Implementation every step that we take in the right direction is a step in the right direction, and should be view and applauded as such. It is to easy to sit back and pick apart how much more someone could have done and to hard to analyze the decisions that a homeowner or builder made based on their budget, knowledge, or experience. I for example am looking to first and foremost design and build houses the best that I can. I continue to learn and grow as a designer, builder and customer. My houses are not perfect, someday I hope they will be more so, but I make an honest effort to help any and all around me in this field and I take any and all advise that will make my houses better, implementing all that I can at this time.

Common green options

Less common

Least common

Why Home Builders and Home Owners Go Green

Right Thing To Do (both)

Builders and homeowners choose to go green because it is obviously the right thing to do. Builders who build a better house have less service issues and a great referral base because their customers are happy and healthy. Customers who have any idea the volume of harmful contaminants that can be in our home chose to go green the health and well-being of the families firstly but these are also people aware of their surroundings. They understand that even though it may not be realized in our lifetimes that choices and changes that we make today will benefit or shackle future generations.

Realized Cost Savings

Timelines are calculated on a case-by-case basis and are very variable.