14 Tips for Understanding Your High-Performance Home
August 26, 2017, by Jarad Miles
First and foremost, we start each HP home with an integrated design process, a more holistic approach to design and construction. During this process our team members share their vision of sustainability and work collaboratively to achieve aesthetic, programmatic, structural and energy-efficiency goals. This allows our team to not only optimize systems and reduce operating costs, but also helps minimize the need for incremental expenses along the way.
During this process we help the client make important decisions about the features of their future home. It’s important that our clients understand how key features work together to enhance comfort and lower their energy bill — and how these benefits are best achieved and maintained over time.
“One of the biggest challenges,” says Birdsmouth Architect Jonathan Lundstrom, “is that clients have to consider how their high-performance home works and how their behaviors affect their home. Sometimes this means replacing old habits with new habits”.
Jonathan made us the following list highlighting the key features of our HP homes (AND some important tips for putting them to good use):
A continuous layer of insulation around all exterior surfaces (walls, roof, foundation), including over the roof and under the building to reduce heat losses and gains. It also helps prevent rot and mold by keeping the sheathing warm enough to prevent condensation.
Tip #1: Keep the doors and windows closed during the coldest and hottest days of the year in order for the home to remain comfortable on the interior. Similar to a cooler in the summer, you want to keep the heat from getting in just as you want to keep your jacket closed in the winter to keep the heat from escaping.
High-Performance Windows and Doors
We have designed your home to allow the winter sun to penetrate the interior of your home as much as possible. During the summer we take advantage of exterior shading devices to stop the sun from reaching the glass and interior, to keep the home cool.
We build with well-insulated window frames and glass. In the winter, triple-pane glass eliminates the feeling of cold drafts next to your windows and doors. Often times our windows open toward the interior of the home — with an insect screen on the exterior and a unique feature to securely lock the window in the open position — while limiting access through the window. This features allows you to leave the windows open for cool evening ventilation while maintaining the security of the home. That said, you can leave the windows and doors open whenever you want. Just as you probably wouldn’t leave your windows open all day (especially on the coldest of winter days) in a regular home, a HP home is no different.
Tip #2: Close the exterior shades during hot summer days (before leaving the house to run errands or heading off to work) and open the windows during cool summer evenings.
Heat Recovery Ventilator (HRV)
We use mechanical ventilation to keep the air fresh, utilizing a low power fan and filter to provide continuous fresh and filtered air, while transferring heat between the fresh intake air and stale exhaust air. This unit commonly referred to as a Heat Recovery Ventilator (HRV) is designed to operate continuously and should remain on at all times, even while away from the home for extended periods of time. The HRV does offer a bypass mode (allowing you to turn off the heat recovery with the press of a button) for those perfectly comfortable days and cool summer nights.
Tip #3: If you suffer from bad allergies or the outside air quality is poor, keep the windows and doors closed to keep contaminants out of the indoor air… just as you would in a regular home.
Tip #4: Similar to a furnace or your vacuum, you should replace your HRV filters once a year (we recommend in the fall) to help maintain the fresh air quality in your home.
A continuous airtight envelope around the building will prevent air leaks (at any junction or joints in materials as well as through materials) while also preventing moisture problems. Typically our airtight layer is the structural sheathing that lies between the exterior insulation and framing members or studs.
Tip #5: It’s best to puncture as few holes as possible in the airtight layer and to close any openings once the mechanical fasteners (used for sealing joints and junctions) have been removed. It’s okay to hang a picture on a wall or add a built-in component, but if you’re renovating or adding a penetration (such as a Comcast cable) make sure any holes get sealed.
Thermal Bridge-Free Construction
Our team designs and details the construction to minimize the transfer of heat through the building envelope.
Tip #6: To further reduce your energy consumption, use natural ventilation when the outside temperature and humidity level are close to your desired indoor temperature.
Our homes are designed with high-efficiency, Energy Star rated appliances focused on minimizing electrical needs. We avoid natural draft combustion appliances that introduce contaminants and moisture into the air. Induction cook tops, which are standard in our high-performance homes, are popular with chefs because of their shortened preheat and cooking times. This way, all the energy goes into cooking the food instead of being lost in the surrounding air.
Tip #7: Not every pot or pan will work with induction heat. The piece must be made of ferrous material and have a flat bottom so direct contact can be made between the surfaces. Cookware made of cast iron or stainless steel are great options. Viking, All-Clad, Staub, and Le Creuset all specify which of their products are induction-compatible. Look for the ‘induction compatible’ marker on any pots or pans to make sure it will work with your range.
Tip #8: You can tell if your current pans will work on an induction cooktop by placing a magnet on the base to see if it sticks to the surface. If it does, the cookware will work with induction heat.
Another standard appliance in our high-performance homes is a condensing or heat pump clothes dryer (ventless). Instead of exhausting the hot air outside (as with your average dryer), these dryers push the hot damp air through a heat exchanger, essentially removing the water vapor and drying and warming the clothes.
Tip #9: Similar to standard dryers after each load, the containment chamber must be emptied and the dryer lint trap cleaned to make sure no debris or lint is clogging the pipes. Note that these units do take a little longer to cycle than a vented unit, although the heat pump units take only slightly longer. A bit of patience in the name of a healthy, long lasting and energy efficient home goes a long way!
Lighting in our homes are fitted with 90-100% LED lamps (light bulbs). LED lamps contain no mercury, last 10 years or more, and do not contribute to heat buildup in your house. When it’s time to replace LED light bulbs, make sure to coordinate the type of light bulb (rated for use in concealed fixtures, dimmable, etc.) with the light fixture and intended use. We often recommend dimmers and controls specifically designed for use in a HP home. Switching these out for a non-compatible dimmer or control could potentially cause issues.
[Image: Courtesy Josh Partee]
We usually install an electric heat pump water heater in our HP homes. Up to three times more energy efficient than conventional water heaters, this system moves heat from one place to another instead of generating new heat directly.
Tip #11: Keep the water heater on the lowest setting possible for providing the heat you need. This will definitely help reduce your energy costs.
Heating and Cooling
Heating is often provided by mini-split systems or ducted heat pumps controlled by your thermostat. The heating load is minimal for our homes and therefore night setback thermostat systems are unnecessary. HP homes are more sluggish to move up or down in temperature since they use such a small amount of power. The good news is that a HP home’s indoor temperature should never fluctuate as a 'regular' house would and therefore need less energy to move temperature rapidly. This would only be an issue when leaving for an extended vacation during the winter. Upon returning, it could take up to eight hours to 'warm up' to your desired temperature. Once warm though, your HP should stay consistently warm for a very long time.
Cooling is minimal and often not required in our high-performance homes when the exterior shading is utilized. When needed, cooling is provided by the same system that provides the heat and is controlled by a thermostat. High-performance homes can be designed to not require cooling, depending on its site conditions and architecture.
Tip #12: Make sure not to block the air supply and return grilles with wall mounts or furniture. In addition, keep the gaps under the bedroom doors clear to allow air flow out of the bedrooms. This will help maintain a balanced comfort level throughout the home.Tip #13: Change the filters as needed for your heat pump. This way your system won’t have to work as hard and your indoor air will be cleaner. Start by changing the filters twice a year. How dirty they get depends on several factors (pets, keeping doors or windows open, living in a dusty area, etc.), so check your filters to determine how often they need to be changed.
Low and No VOC Materials
On average, people spend 80% of their time in buildings. This is why we build using products and materials with low or no VOC’s (Volatile Organic Compounds).
Tip #14: Purchase cleaning supplies, household goods and furnishing that contains no or low VOC’s.
If you have any questions about your own high-performance home or about building one in the future, please call us at (503) 753-9692!