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. http://bobcatandsun.com/were 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. http://www.infloor.com



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.

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