Manual of Modern Hydronics SECOND EDITION • Residential • Industrial • Commercial • Snow and Ice Melt Professional Radiant Heating Solutions MANUAL OF MODERN HYDRONICS This manual is published in good faith and is believed to be reliable. Data presented is the result of laboratory tests and field experience. IPEX maintains a policy of ongoing product improvement. This may result in a modification of features or specifications without notice. www.warmrite.com www.ipexinc.com © 2004 by IPEX. All rights reserved. No part of this book may be used or reproduced in any manner whatsoever without prior written permission. For information, address IPEX, Marketing, 2441 Royal Windsor Drive, Mississauga, Ontario L5J 4C7. © 2004 IPEX WR003UC INTRODUCTION MODERN HYDRONICS Each year, construction begins on tens of thousands of new buildings all across North America. Thousands more undergo renovation. Whether new or remodeled, most of these buildings will require the installation or alteration of a comfort heating system. Along with hundreds of other decisions, the owners of these buildings must eventually select a heating system. Unfortunately—and in most cases unintentionally—the choice is often based on factors that in the end, don’t provide the comfort the owner or the occupants are expecting. In many cases the heating system, which is often thought of as a necessary but uninspiring part of the building, is selected solely on the basis of installation cost. In other cases, the selection is based strictly on what the builder offers or recommends. Still other times, the choice is based on what’s customary for the type of building being constructed or its location. Such decisions often lead to years of discomfort in thermally-challenged buildings. In retrospect, many people who have made such decisions—and lived with the consequences—would quickly change their mind if given the opportunity. Most would gladly spend more (if necessary) for a heating system that meets their expectations. It doesn’t have to be this way! Few people don’t appreciate a warm, comfortable interior environment on a cold winter day. A warm home or workplace lets them forget about the snow, ice, and wind outside. It’s an environment that encourages a sense of well being, contentment, and productivity. Hydronic heating can provide such an environment. It can enable almost any building to deliver unsurpassed thermal comfort year after year. Hydronics technology is unmatched in its ability to transfer precise amounts of heat where and when it’s needed. The warmth is delivered smoothly, quietly, and without objectionable drafts that cause discomfort, or carry dust 1 THE IPEX MANUAL OF MODERN HYDRONICS and airborne pollutants through the building. Properly The outer PEX layer protects the integrity of the designed hydronic systems are often significantly less aluminum core, shielding it from abrasion or chemical expensive to operate than other forms of heating. reactions when embedded in materials such as concrete. The inner PEX layer provides a smooth A wide variety of hydronic heating options exist for surface for excellent flow characteristics as well as everything from a single room addition to huge chemical resistance. industrial and commercial buildings. Knowledgeable designers can configure systems to the exact needs of The unique construction of Kitec tubing also provides each building and its occupants. The systems can then excellent flexibility for easy installation, especially in be installed without compromising the structure or tight situations where rigid pipe is simply out of the aesthetics of the building. question. In short, hydronic heating is for discriminating people Unlike most plastic tubing, Kitec retains the desired who expect buildings to be as comfortable to live and shape when bent. It can also be easily straightened for work in as they are elegant to look at. Hydronic heating a neat and professional appearance in exposed sets the standard of comfort, versatility and efficiency locations. against which other forms of heating should be Kitec pipe is truly a “universal” product suitable for all measured. types of service in hydronic heating systems. From heated floor slabs, to heated walls and ceilings or Now Is the Time snowmelting systems to baseboard circuits, you’ll find There has never been a better time for heating the qualities Kitec possesses will soon make it the professionals to be involved with hydronics. New tubing of choice for all your hydronic heating needs. materials, design tools and installation techniques offer unprecedented and profitable opportunities to From piping to systems progressively-minded professionals. In addition to Kitec tubing, IPEX also offers a IPEX produced this manual to assist you in deploying complete line of accessories such as tubing hydronic heating technology using the latest design connectors, adapter fittings, manifolds and WarmRite and installation strategies. It is our goal to help you to Floor® Control Panels. These products are designed to meet the exact needs of your customer using the finest allow fast and easy installation and can be used in a methods and materials available for modern hydronic variety of applications. heating. We want to inspire your thinking, and give you In the sections that follow, we’ll show you how to apply a “can do” attitude when faced with job requirements these products in new ways that let you design and that often lead to compromise when undertaken install systems that epitomize the quality and comfort without the versatility hydronics has to offer. hydronics has long been known for. These are techniques that let you profitably take on the A Universal Piping System challenging jobs others stay away from while steadily Piping is obviously a crucial component in any building your reputation as a true comfort professional. hydronic system. Not only must it safely contain heated Together with IPEX, you can successfully harness the and pressurized water but it must also resist corrosion, almost endless possibilities offered through modern withstand thermal cycling and be easy to install. hydronics technology. Kitec® XPATM pipe was launched by IPEX in 1988 as a multipurpose pressure pipe with many potential uses in hydronic heating, including potable water distribution. Kitec’s construction combines the best properties of both aluminum and cross-linked polyethylene (a.k.a. PEX) to create a unique composite tube that can be used in applications often beyond the limits of either metal or plastic alone. The aluminum core of Kitec pipe provides strength, yet allows for easy bending. It results in a tube that expands and contracts far less than all plastic tubing when heated and cooled. It also provides an extremely effective barrier against oxygen penetration, which can lead to corrosion of other hydronic system components. 2 THE IPEX MANUAL OF MODERN HYDRONICS TABLE OF CONTENTS Section 1: Consider the Possibilities! . .7 Section 2: Heat Source Options . .13 Section 3: Water Temperature Control . .21 Section 4: Radiant Floor Heating Methods . .33 Section 5: Radiant Walls and Ceilings . .57 Section 6: Manifold Systems . .63 Section 7: Pre-Assembled Control Panels . .73 Section 8: Distribution systems for Hydronic Heating . .87 Section 9: Designing Multiple-Load Hydronic Systems . .99 Section 10: Radiant Pipe and Tubing . .109 Section 11: Hydronic Snow and Ice Melting . .115 Section 12: IPEX RadiantTM Design Software . .131 Appendix 5 SECTION 1 CONSIDER THE POSSIBILITIES! Question: What kinds of heating loads can be handled using modern hydronics technology? Answer: Almost any load you can think of! For years the concept of hydronic heating evoked thoughts of cast-iron radiators or fin-tube baseboards in homes and commercial buildings—and not much else. Early hydronic systems were usually classified as being “residential” or “commercial” in nature. Residential systems were the domain of plumbing / heating contractors. Rule of thumb design was usually good enough given the limited variety of systems installed. The piping and control methods used in these systems remained essen- tially unchanged between the 1950’s and the 1980’s in North America. Commercial hydronic systems were a world apart from their residential counterparts. Techniques such as primary / secondary piping, multiple water temperature distribution systems, and outdoor reset control were successfully deployed in commercial systems, but almost never considered for residential applications. A New Era for Hydronics Times have changed considerably, hydronically speaking. Residential and commercial systems now share some common piping and control strategies. Successful installation strategies first developed decades ago are being “redeployed” using modern materials and control strategies that ensure decades of reliable and energy efficient operation. 7 THE IPEX MANUAL OF MODERN HYDRONICS The days when hydronic systems consisted solely of One System that Does It All cast-iron radiators, copper or black iron pipe and fin- tube baseboard are gone. New hardware such as Kitec The concept that best describes modern hydronic pipe and WarmRite Control Panels now make it heating is: possible to install quality systems that serve a One heat source serving multiple loads multitude of heating loads. Modern systems can incor- porate a variety of heat emitters. Each are selected to Those loads include: match the exact thermal, aesthetic and budget • Radiant heating of floors, walls and ceilings constraints of a project. • Baseboard