Bend Oregon Solar Homes
Building a passive solar home in Bend Oregon is not as easy as you may think. There are many things to consider when building a solar home. My wife and I are currently living in our new passive solar home. We have been here for less than a year. We do not have solar panels that generate electricity and we do not have solar hot water.
Orientation
When building the solar home the home should have at least 75% of the windows facing true south or with 10% of true south. We built our home 10% east of true south. This gives us a little more morning sun and less afternoon sun.
Double Wall Construction
Number one is the type of construction you are going to use. One of the more common practices in building an energy efficient home in Central Oregon is with double wall construction. This is where 2X4 lumber is used to frame the two walls leaving a hollow space in the middle for insulation.
This way there is not thermal bridging where in there is no one piece of lumber that has contact with the exterior and interior at the same time. This greatly increases the R value of the wall by also allowing more insulation as to compared to a regular 2x6 wall construction. My wife and I are currently living in a home with 12 inch walls and it is very efficient.
Style of Home
As we are nearing retirement age we chose to build a single level Prairie Style home. A Prairie style home is conducive for a passive solar home in that is generally has a low roof pitch and allows for 36 inch overhangs which we will discuss later.
Heat Source
We chose the relatively new ductless mini split heat pump. The heat pump cools as well as heats and is very efficient. This mini splits have up to 4 inside units per heat pump. The units are very quiet but not completely silent. One draw back is they do not have a back up system and do not work properly when the temps are in the teens or below.
We chose a propane fireplace as our back up system. It is thermostatically controlled and will kick on if the electricity of off or if the out side temperature is extremely cold.
Thermal Mass
Put simply thermal mass the the amount of solid material put into a home. Cement, rock, granite, tile represents the most commonly used materials. Cement floors are commonly used for thermal mass but we wanted wood floor so We choose to put a Trombe wall in our home.
The Trombe wall a cement wall that sits behind the south facing windows that have a high solar heat gain coefficient.
Our wall in 36 inches high and 10 inches thick. We covered it with decorative rock which adds more mass and looks great. It's very unique.
This wall absorbs the solar heat all day during the winter and slowly radiates back in to the house at night. It's important to have a system to insulate the windows at night to hold the heat in and the cold outside where it belongs.
This past winter when it was really cold outside the temperature between the windows and the wall got up to 94 degrees. When it reaches 74 or 75 in the house I open some windows. It really feels good to have fresh air coming in your home in the dead of winter.
Windows
The type of windows and their placement is very crucial in a solar home. We used casement windows in that they are the most efficient. All windows except the ones with a high solar heat gain coefficient should have Low-E glass.
Heat Recovery Ventilation System (HRV)
Our home is so air tight we felt it necessary to install an HRV. The heat recovery ventilation system is an air to air heat exchanger. This system pumps fresh air into the main living area while exhausting stale air out of the bathrooms.
I'm told our is 80% efficient. Which I take to mean we only loose 20% of the heated air that we are exhausting out of the home. That will vary according to the outside temperature. Do not install an Energy Recovery Ventilation system (ERV) in a home in Central Oregon.
Questions?
I have learned many things during the construction and now living in our passive solar home. I am available for consultation while doing a walk thru of our home. There are things I would do differently and things I have learned since we moved in.
Most of the contractors, architects and designers I talked to have not lived in a passive solar home. I am not aware of any Trombe walls in Central Oregon. I'm not an expert in this field but do have practical experience in the construction and use of a passive solar home. Contact me with any questions you might have about solar homes or Bend Oregon real estate in general.
Jim Johnson, Owner 541-389-4511 call or text
