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Title: Technology Solutions Case Study: Hydronic Systems: Designing for Setback Operation

For years, conventional wisdom surrounding space heating has specified two points: size the mechanical systems to the heating loads, and setting the thermostat back at night will result in energy savings. The problem is these two recommendations oppose each other. A system that is properly sized to the heating load will not have the extra capacity necessary to recover from a thermostat setback, especially at design conditions. Properly designing a hydronic system for setback operation can be accomplished but depends on several factors. Determining the appropriateness of setback for a particular project is the first step. This is followed by proper sizing of the boiler and baseboard to ensure the needed capacity can be met. Finally, control settings must be chosen that result in the most efficient and responsive performance. This guide provides step-by-step instructions for heating contractors and hydronic designers for selecting the proper control settings to maximize system performance and improve response time when using a thermostat setback.
Publication Date:
OSTI Identifier:
Report Number(s):
Research Org:
Consortium for Advanced Residential Buildings
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Office (EE-5B) (Building America)
Country of Publication:
United States
residential; Residential Buildings; CARB II; Building America; gas-fired, modulating condensing boilers; outdoor reset control; night setback; AFUE; right-sizing; hydronic systems; mass storage; ACCA Manual J; boost control; baseboard convectors; indirect DHW system; combustion efficiency; recovery period