NetZero in Alaska
The Sunrise Home is the latest design in our quest to develop sustainable shelters for the Arctic incorporating no fossil fuel based heating system, and an annual zero energy requirement. The prerequisite to making zero energy buildings in a 14,000 HDD climate possible is a highly efficient building and very low energy requirements built to stringent Passive House Benchmarks. It requires an optimized passive solar design with additional insulated mass within the thermal envelope and a minimum of 0.6 SHGC on south facing windows equiped with thermal shutters. In addition, it requires an integrated design of all the renewable energy systems molded together with an annual seasonal heat storage tank.
Passive Home North - or 12 Tons of Insulation
The Sunrise home is the northern most Passiv Haus in North America and a milestone in energy efficiency. The home is super insulated with over 12 tons of cellulose. Space heat is provided by a 480 SF solar thermal system with an internal 5000 Gal annual heat storage tank and a custom masonry heater. There is no conventional fossil fuel source or backup heat. The home features many prototype designs and ideas from the mass loaded foundation system to the diffusion open wall system without a typical vapor barrier. The home was specifically designed to utilize passive solar heat gains as much as possible while maintaining a comfortable indoor temperature. From mid-February through early November, the passive heat gain from the sun maintains the home at 68-72F without additional heating. The main Passiv Solar gain is generated via the 16’x 9’ window on the main floor with SHGC 0.63/ U-0.20 glazing. This window incorporates a summer sunshade and an external R-40 thermal shutter for nightly heat retention. An evaporation pond is located in front of the window to provide additional natural cooling in the summer.
Green Building and Bau-Biology
Besides superinsulation, the home features many Green Building and Bau-Biology techniques from VOC free adhesives, paints and stains to dual flush toilets and high efficient appliances. Local materials were used as much as possible during construction and the natural feel creates a connection between the inside and the outside environments as well as creating the feeling of 'home". Air filtration with proper ventilation creates a healthy indoor climate. All the systems are networked and integrated with a smart panel which allows for remote monitoring and interaction with the home's systems.
The current missing link is the installation of a 5KW Photovoltaic system which is planned to be installed soon to bring the home to a zero energy building.
- 2,300 SF living space (200 SF seasonal storage), 3 Bedrooms, 2-1/2 bathrooms
- Slab at R-63 with 180 tons of insulated internal mass for passive and active heat storage
- Walls at R-75 dense packed cellulose
- Roof at R-115 blown-in cellulose in cold attic truss
- Windows glazed for maximum solar heat gain coefficient on all south facing glass, no windows due north
- Thermal shutters from R-20 to R-40 on all windows
- Preheated ventilation air with a German HRV Zehnder ComfoAir 350 in combination with a Comfond 400 LF ground loop.
- Heating demand of 4.33 kBTU/(ft2yr) modeled in PHPP07 (Passiv Haus software)
- Air-tightness of 0.48 ACH50 on blower door test to PH standard at pressurization and depressurization.
Research and Monitoring
The Cold Climate Housing Research Center has installed many sensors throughout the different elements of the home to monitor and research its performance. The home is a prototype that helps us learn how to optimize the integrated systems to make them more cost efficient and applicable in future projects and retrofit applications. The data collected and the experience gained will show that even in our extreme cold climate, buildings can function very well without traditional heating systems and ever increasing utility expenses.
Disclaimer: The PHPP calculated heat demand was modeled with the use of thermal shutters on all windows with a 58% utilization factor of the shutters. Real world data from the installed data loggers is needed for validation of the assumed values. Once actual measured performance is verified we will submit for Passive House certification – or not, depending on the monitoring results.
Design – Build by REINA, LLC - Thorsten Chlupp