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Title: Measure Guideline: Condensing Boilers - Control Strategies for Optimizing Performance and Comfort in Residential Applications

Abstract

The combination of a gas-fired condensing boiler with baseboard convectors and an indirect water heater has become a common option for high-efficiency residential space heating in cold climates. While there are many condensing boilers available on the market with rated efficiencies in the low to mid 90% efficient range, it is imperative to understand that if the control systems are not properly configured, these heaters will perform no better than their non-condensing counterparts. Based on previous research efforts, it is apparent that these types of systems are typically not designed and installed to achieve maximum efficiency (Arena 2010). It was found that there is a significant lack of information for contractors on how to configure the control systems to optimize overall efficiency. For example, there is little advice on selecting the best settings for the boiler reset curve or how to measure and set flow rates in the system to ensure that the return temperatures are low enough to promote condensing. It has also been observed that recovery from setback can be extremely slow and, at times, not achieved. Recovery can be affected by the outdoor reset control, the differential setting on the boiler and over-sizing of the boiler itself.more » This guide is intended for designers and installers of hydronic heating systems interested in maximizing the overall system efficiency of condensing boilers when coupled with baseboard convectors. It is applicable to new and retrofit applications.« less

Authors:
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy Building Technologies Program
OSTI Identifier:
1079734
Report Number(s):
DOE/GO-102013-3895
KNDJ-0-40342-00
DOE Contract Number:  
AC36-08GO28308
Resource Type:
Technical Report
Resource Relation:
Related Information: Work performed by Consortium for Advanced Residential Buildings (CARB), Norwalk, Connecticut
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; CONDENSING BOILERS; AFUE; CONTROLS; OPTIMIZIATION; HEATING; OUTDOOR RESET; BASEBOARDS; RESIDENTIAL; RESIDENTIAL BUILDING; CONSORTIUM FOR ADVANCED RESIDENTIAL BUILDINGS (CARB); BUILDING AMERICA; Buildings

Citation Formats

Arena, L. Measure Guideline: Condensing Boilers - Control Strategies for Optimizing Performance and Comfort in Residential Applications. United States: N. p., 2013. Web. doi:10.2172/1079734.
Arena, L. Measure Guideline: Condensing Boilers - Control Strategies for Optimizing Performance and Comfort in Residential Applications. United States. https://doi.org/10.2172/1079734
Arena, L. 2013. "Measure Guideline: Condensing Boilers - Control Strategies for Optimizing Performance and Comfort in Residential Applications". United States. https://doi.org/10.2172/1079734. https://www.osti.gov/servlets/purl/1079734.
@article{osti_1079734,
title = {Measure Guideline: Condensing Boilers - Control Strategies for Optimizing Performance and Comfort in Residential Applications},
author = {Arena, L.},
abstractNote = {The combination of a gas-fired condensing boiler with baseboard convectors and an indirect water heater has become a common option for high-efficiency residential space heating in cold climates. While there are many condensing boilers available on the market with rated efficiencies in the low to mid 90% efficient range, it is imperative to understand that if the control systems are not properly configured, these heaters will perform no better than their non-condensing counterparts. Based on previous research efforts, it is apparent that these types of systems are typically not designed and installed to achieve maximum efficiency (Arena 2010). It was found that there is a significant lack of information for contractors on how to configure the control systems to optimize overall efficiency. For example, there is little advice on selecting the best settings for the boiler reset curve or how to measure and set flow rates in the system to ensure that the return temperatures are low enough to promote condensing. It has also been observed that recovery from setback can be extremely slow and, at times, not achieved. Recovery can be affected by the outdoor reset control, the differential setting on the boiler and over-sizing of the boiler itself. This guide is intended for designers and installers of hydronic heating systems interested in maximizing the overall system efficiency of condensing boilers when coupled with baseboard convectors. It is applicable to new and retrofit applications.},
doi = {10.2172/1079734},
url = {https://www.osti.gov/biblio/1079734}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed May 01 00:00:00 EDT 2013},
month = {Wed May 01 00:00:00 EDT 2013}
}