No Cold Feet at Desert Rain

Twelve degrees F. here at my home outside of Bend today. I am currently renting an old farmhouse with inadequate insulation, low quality double paned windows, arctic air through the electrical outlets, and  ice-cold floors that quickly freeze the feet.  I rarely use the high-cost, high- energy consumption, electric wall heaters.  That leaves me with a pellet stove – warm enough if I’m in the same room, additional layers required in the rest of the house.  While I sit writing in my wool  sweater and booties, I’m thinking of Desert Rain – all the elements of energy efficient home design and building technology that make a home comfortable, no matter the outdoor air temperature.

The ADU received the final application of spray foam insulation a few days ago.

Attention to detail with spray foam insulation ensures an airtight seal.












At the project site yesterday, the Energy Conservation Insulation crew was back with more spray foam insulation.  The process started in July with spraying the ceiling area and around duct work and vent stacks. The initial coat of spray foam insulation in the walls was installed to about half the final thickness. Without the obstructions of wires and pipes, the spray foam can more easily penetrate the wall cavities, creating a better seal.  The electrical and plumbing system work has been in progress throughout the fall.  Mike Wagnon with All Phase Electric Service and Beau Parazoo with Parazoo Plumbing confirmed that both the electrical and plumbing systems passed inspection this past week.  With those approvals in place ECI is working on the final layer of spray foam insulation. Desert Rain will have R-values more than twice the code requirement. ECI also uses an infrared camera to find potential ‘air leaks’ and weak spots in the insulation.  The attention to detail is apparent as spray foam is visible at every location where there is a possible connection to outside air.  The insulation, combined with the whole house caulking that stops air infiltration, contributes to the temperate comfort.

So many wires! The electrical system passed inspection this last week.


Plumbing system in place and passed inspection.












While I covet the idea of good insulation and no cold air infiltration, I am absolutely envious of the infloor hydronic heating system.  The 4″ thick concrete slab is the thermal mass for both the infloor heating and any passive solar gain that permeates the structure.  That concrete retains and radiates the warmth.  The energy efficient heat pump has been working during my last few visits keeping the space warm even without an airtight front door and with construction underway. I can also appreciate the choice of the Loewen windows.  Loewen uses thicker glass than most other window manufacturers. The triple glazed windows consist of two full half-inch air spaces, argon gas, Low E2 technology, a special cladding design to keep exterior metal away from the interior of the window, and edge sealing.  The craftsmanship of the window frame is cabinet quality for a tight seal. The window installation process with pre-flashing details that prevent water and air infiltration is essential.  The results – gradual and uniform transition from outside to inside temperature and energy efficiency.

Outside in the winter cold, work continues on the garage soffits with reclaimed lumber.


Though inside Desert Rain is comfortable, work also continues outside in the bitter, winter weather.  The framers have installed windows and are continuing work on the garage.  They are using more of the reclaimed lumber for the soffits – the same material that is on the main house.  As each element of design is added the garage becomes visually connected to the other structures.  The project site is revealing the ‘compound’ idea that Barb and Tom had envisioned.  It will be a compound of energy efficient dwellings, offering ideal comfort to the people inside – no cold feet here.






Turning Up the Heat

Summer has finally arrived here on the high desert.  While temperatures outside were climbing, inside Desert Rain, Pat and Scott with Bobcat and Sun Inc. installing the ‘Infloor’ tubing  that will heat the house during the cool months. Infloor radiant heat, combined with the passive house design, will keep Desert Rain warm and comfortable.

Radiant heat in the process of installation. The tubing is spaced at approximately 8″ on center. The paper layer underneath shows cabinets, appliances, and areas where tubing will not be needed.



Infloor heating works by pumping heated water through distribution tubing.  The PEX or AL PEX tubing is selected by comparing pressure and temperature ratings, as well as, the wall thickness for heat transfer and durability.  Copper or brass manifolds provide complete control over each loop and will precisely regulate the flow and allow for individual loop control as well as isolation, air elimination, and purging capabilities.  At Desert Rain tubing was stapled to the wood sub-floor on 8” centers.  In the living, kitchen, dining area of Desert Rain a 4” thick slab of pre-colored concrete was poured over the tubing.  The concrete creates thermal mass – storing and releasing the radiant heat.

The tubing is installed throughout the house – ready for the concrete slab. The black hose delivers the concrete slurry from the truck to the floor.

Did you know?
A typical evacuated tube collector will average around 60% efficiency throughout the year, even taking cloudy days into consideration. It will produce around 70% of hot water requirements throughout the year (more in the summer, and less in the winter)

Some of the floor area at Desert Rain will eventually be covered with reclaimed myrtle wood flooring.  Those areas will first receive a thin slab underlayment of gypcrete over the radiant heat tubing.  Gypcrete is a light weight gypsum and sand concrete that will provide thermal mass for the floor areas that are not concrete slab. Radiant heat moves from the tubing or concrete through the air in waves, similar to radio waves.  It heats without pressurizing the air within the house, reducing heat loss and saving energy.  As heat moves to cooler surfaces like walls, furniture and people, it warms those surfaces.  Radiant heat is always trying to reach thermal equilibrium so the whole room or house heats evenly from the floor up.

Keith and crew from Central Oregon Concrete pouring the 4″ thick slab. The concrete is pre-colored and will later be polished to create a beautiful, finished floor that provides thermal mass.

The water in the radiant heat system at Desert Rain will be heated with three options.  The desired 120 degree water temperature will rely first, on the solar thermal system. The solar thermal system heats water from the sun’s light. There will be a set point on the solar thermal system.  If the water temperature is depleted to 90 degrees the source will automatically switch to the heat pump.  These two systems should be sufficient to keep the water at the desired temperature. There is an electrical heat source in place as back up.

Learn more about radiant heat and solar thermal systems at the INFLOOR website.  They share a wealth of detailed information: available systems, installation process,  products, components, and frequently asked questions.



Where does all that tubing connect? Each loop will be connected to a manifold that will control and regulate the system.


Passive house design, thermal mass heat collection through concrete and gypcrete, tubing throughout the house filled with solar thermal heated water – this winter Desert Rain will be warm and absolutely, radiant!


The kitchen and living area after the concrete slab was poured. The concrete takes about 28 days to set.