Timber Frame Energy Efficiency
Why timber frame? Energy efficiency is yet another reason.
Want to save money on your energy bills to help pay off your mortgage? Conserve valuable resources? Reduce pollution? Be more comfortable in a draft free home? All of these are reasons to make certain that your new timber frame home is as energy efficient as it is beautiful. Not many years ago a 2 X 4 stick-built house with R-11 fiberglass insulation was considered adequate. Those days are history. Insulation options have greatly improved so that R-24 walls and R-40 roofs are easily attainable.
Structural Insulated Panel Systems
One of the best methods for building a highly energy efficient home is to use an insulated panel system. These may be structural (structural insulated panels are called SIP’s) or non-structural. The latter are used to enclose timber frames. SIP’s are used for non-timber framed additions in a hybrid home. The panels are constructed of foam insulation — expanded polystyrene (EPS) or polyurethane — sandwiched between two layers of 7/16-inch oriented strand board (OSB). The panels employ a tongue and groove connecting system that forms an interlocking, uninterrupted insulation barrier against heat loss, heat gain or air infiltration.
Insulated panels have proven to be much more energy efficient than stick framed wall and roof systems. In a stick framed wall, the wood studs result in a cold spot at regular intervals, since wood is not a good insulating material and has a R-Value of about 1 per inch. This means that each 2 X 6 stud provides a mere R-6 of insulation. In addition, the fiber glass batts tend to have gaps, to get crimped or compressed, and to loosen around electrical outlets and pipes. These cause drafts and greatly reduce the overall insulating value of the batts. So although the batts may be a R-11 or a R-17, actual whole wall performance will be much lower.
Panels have a continuous foam core that does not allow for drafts, cold spots, and reduced insulation value. As a result, they have much better whole wall performance,. They enable you to purchase a smaller HVAC system from the outset, providing immediate savings. You continue to save from 40%-60% on heating and cooling costs, year after year. At the same time, your home will be much cozier and draft-free in the winter and cooler in the summer.
Energy Recovery Ventilator
With the energy efficient timber frame, we recommend installation of an energy recovery ventilation system (ERV). An energy recovery ventilation system will improve the indoor quality of the air and keep the humidity in the home at a constant. In any climate, this is beneficial to help control indoor relative humidity. In the heating season, an ERV will preserve essential moisture in the home while keeping it below excessive levels. During cooling season it minimizes the added moisture that the incoming airflow may contain.
An energy recovery ventilator continuously exhausts stale, polluted indoor air and replaces it with fresh outdoor air. Energy from the indoor air (warm air in winter, cool air in summer) is extracted and transferred to the fresh incoming air so there is little energy loss.
The energy recovery ventilator system will be installed by your local heating and air conditioning contractor and be an integral part of your heat and air conditioning system. In heating climates, remember heating the air may dry it to below a desired humidity level, in which case added humidification may be needed.
The use of an energy recovery ventilation system in your timber frame home will enhance the indoor air quality and humidity levels to the most comfortable zone for you and your family.
Energy Efficient Windows
The energy efficiency of the walls and roof are not the only R-values today’s homeowners need to consider. Windows let in more than just light and scenic views. The wrong choice in windows and doors can negate much of the energy efficiency a well-informed homeowner has been able to gain through an effective insulation system. In addition to their respective insulating properties, any quality window or door greatly reduces the infiltration of outside noises.
Keep in mind that a thermal window merely means it is two panes of glass, which has an R-value of no more than 2. There are glazing options available that more than quadruple that R-value. In addition to keeping out the cold there are also options that address specific needs. A window in a north-facing wall does not have the same job to perform as one in a south-facing wall. By carefully selecting from the various glazing options homeowners can fine-tune their homes.
For example, a glaze to produce Low E (low emissivity) glass not only increases a window’s R-value, but also blocks out ultra violet rays, thereby protecting your timber frame, and the furniture, rugs and draperies.
Another glazing option eliminates unwanted heat gain. While passive solar is the least expensive method of heating a home, gaining heat is desirable only in winter and that bank of south facing windows will still be there come summer. It is, for example, usually preferable to place skylights on north facing roofs, thereby enjoying the sunlight year round without suffering from unwanted heat in the summertime. Remember that a window that is too cold (or too hot) to sit near takes away from the usable living space in your home.