InfraMation 2004 Proceedings

ITC 104 A 2004-07-27

Infrared Applications for Post Construction Radiant

Heating Systems

Eric G. Amhaus, Professional Investigative Engineers

Edward L. Fronapfel, Professional Investigative Engineers

ABSTRACT

This paper will review and discuss the benefits of infrared thermography as its technology applies to the

investigations and inspections of various in-floor (interior) and concrete slab (interior and exterior) radiant

heating systems, both electrical and fluid systems. The purpose of this paper is to outline the various

applications of infrared thermography for investigation of the systems, as presented in a case study format.

The technique illustrates how infrared

thermal imaging cameras

can be utilized to determine such

post-construction items as

identification of system zones, failure or impeded heat loss analysis, sensor

identification, leak analysis, and

line system identifications for intrusive testing or slab coring.

Both resistance electrical and fluid radiant heat systems have become widely used in high-altitude and cold,

mountainous regions such as Colorado. Initially, the objective of such systems was to reduce the need for

manual methods of snow and ice removal from pedestrian or vehicular surfaces, but these systems have

recently become fairly common forms of residential interior heating and temperature control in higher end

homes. Manufacturer and design deficiencies, as well as installation defects, result in system malfunctions

and non-performance issues. The cost of the failures is staggering, considering the cost to remove finish

materials, determine the location of the problem, and then rebuild the system and replace the finish materials.

Infrared thermography can help identify and aid in the development of positive solutions both in the post

construction and pre-construction stages.

Keywords

:

In-floor, interior, exterior, slab, radiant, electrical, fluid, construction, zoning, sensor, leak, testing,

cold, mountainous, heating, temperature, homes, construction.

INTRODUCTION AND HISTORY

Radiant heating systems were first invented and utilized by the Romans and ancient Koreans, who built

fireplaces (i.e., furnaces) with extended flues under rock or masonry floors for natural heat distribution.

Hydronic (or hot water-based) radiant flooring was founded in the United States beginning in the late 1930’s.

These systems primarily consisted of wrought iron pipe, but they were quickly abandoned with the outbreak of

World War II, when the demand for steel and iron was great. Shortly thereafter, radiant heat systems in the

U.S. began to utilize soft copper tubing; however, systematic failures were identified in these systems due to

electrolytic corrosion between the copper and concrete reinforcement and line breakage due to the movement

of concrete (settlement, heave, expansion, and contraction). With the new era and advent of plastics, in-floor

radiant heating manufacturers turned to the new technology of plastics for advancements with in-floor heating

elements.

This paper will not attempt to encompass or address the varying types of radiant heating systems and their

positive performance characteristics or failure mechanisms, but rather, it will set forth a means by which

infrared thermography can be utilized as a valuable tool in investigating performance flaws and design or

installation deficiencies in these types of heating systems.

INTERIOR SYSTEM PERFORMANCE AND ZONING

Similar to almost any other construction element, proper design and installation of an in-floor radiant heat

system (fluid or electrical) are vital to proper system performance. Infrared thermography can be utilized to

detect such design or installation deficiencies that result in system failures or inadequate performance.