In “A Close Look at Common Energy Claims” (6/08), Martin Holladay makes the following statement about the voluntary lowering of thermostat settings in homes with radiant floor heating: “The only problem with the theory is that no reputable study has ever shown it to be true, while at least one study has disproved it.” This appears to be based on hearsay and one rather small, unscientific survey conducted by a Canadian utility company. A little digging into “operative temperature” would quickly debunk Mr. Holladay’s assertion. ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) has done extensive research in this field. The fact is that as the radiant component of comfort increases, the convective (air temperature) component decreases. It is not just a theory, it is well-proven.
Mr. Holladay also concludes that the lower water temperatures required by a radiant system would result in “very minor energy savings.” Again he shows his lack of understanding. A hot-water baseboard system operates at around 180°F to 200°F, whereas a radiant floor system often operates between 100°F and 130°F. High-efficiency...
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