UTILIZATION OF RESULTS
The results of this research project are intended to aid the developers of radiant simulation modules. The data, from over a 2-year period, will provide a baseline from which simulation results can be compared. There are sufficient envelope, system and climate data points to make reasonable determinations as to the accuracy of the simulation model.
Already, two thesis projects have utilized the Carefree performance data to make comparisons with the results of the developing Energy Plus radiant module. They have identified areas that need further module development that will be the subject of ASHRAE papers.

CONTROL STRATEGY
At the Carefree facility, there are other refinements to the control strategy that could be investigated. Can the floor panel (along with a dehumidification system) alone be used to cool the house during a Phoenix summer? What temperature of floor would best shift the load to off-peak. Refinements after two more seasons of operation should optimize the performance of the Carefree house.

DEVELOP A STANDARD CONTROL SYSTEM PACKAGE
For year round control of heating, cooling, ventilation and dehumidification, develop a hardware and software package for radiant/convective systems. Hardware is currently available, but it is usually sized for larger commercial work (although this is required for the larger homes today). Simplify the system requirements. Work to reduce the number of sensors. When this project started, it was intended to use an operative temperature sensor that was under development, but that device did not materialize. Recently, a room operative temperature sensor, with radio frequency transmission rather than being hard wired, has appeared in the European market (Olesen 2001). These small units are mobile and can be located near the occupant, say on a table. Besides measuring the operative temperature, it can be set for the desired temperature. In the Carefree house, a single unit in each zone could replace 4 sensors. Viewing the data on floor temperatures, it appears that maintaining a floor surface temperature in the range of 71-73°F throughout the year may simplify some aspects of the control system.

DEVELOP THE "SEASONAL TEMPERATURE" SENSOR
The seasonal temperature has proven to be a good indicator for making control decisions at the Carefree house. It provides a close approximation of the average daily temperature over the past 24 hours. Burying a sensor in a "standard mass" would be worth considering for the more complex residential and small commercial control systems as a reference temperature, and the basis of making decisions. Devising a standard "seasonal temperature mass" is suggested. It could be prefabricated of concrete, with a sensor buried inside, and brought to the site, Or it could be built on site to a standard specification and incorporated in the structure.

FURTHER COMFORT LAB RESEARCH
Maybe more comfort lab testing should be considered. Lab tests up to now have controlled space conditions by supply air. Maybe different results could be obtained if surface temperatures were controlled, as in a passive situation or as would be found with a year round radiant heating and cooling system. In summer conditions, frequently the ceiling is warmer than other surfaces.

DEVELOP RADIANT/CONVECTIVE SIMULATION TOOL
Further work is needed to produce a usable radiant/convective simulation tool. The existing EnergyPlus tool showed good results in predicting passive performance, but the active radiant system module needs further development iterations, particularly related to defining the various components that might be utilized. The lack of such a user friendly tool is probably the biggest hindrance to the design and specifying of radiant systems. The radiant industry should help fund the tool's development.

FURTHER DEMONSTRATION
Construct a follow-on demonstration residence (or small commercial building) utilizing lessons learned from the Carefree project. Experiment with various methods of active thermal storage. Walls using insulated concrete forms (ICF), but removing the interior forms after the concrete is set may have some promise.