Pgm 7 Hot Water Boilers (1)

Introduction

  • Title: Hot Water Boilers

  • Purpose: Explore hot water boilers and their operation.

Course Overview

  • Topics include:

    • Heating with hot water

    • Basics of heat loss and calculations

    • Sizing and selection of hot water boilers

    • Boiler components and radiation

    • Hot water piping system components

    • Discussion of different piping systems and arrangements

    • Designing a typical hot water boiler system

Heating with Hot Water

  • Definition: Heating with hot water involves a system consisting of a boiler, circulator, water piping, and room terminals (baseboard, radiators, or radiant panels).

  • Heat generation and flow:

    • Water is heated in the boiler.

    • Travels through piping to room terminals.

    • Water cools down while distributing heat, then returns to the boiler.

Basic Heat Transfer Processes

  • Conduction: Heat transfer through direct contact (e.g., hot water heating an aluminum fin baseboard).

  • Convection: Heat transfer through gas or liquid movement; creates airflow patterns (e.g., heated air from aluminum baseboard fins).

  • Radiation: Heat transfer without direct contact; e.g., warmth from an open fire.

  • Evaporation: Liquid turning into vapor to regulate body temperature.

Types of Hot Water Systems

  • Gravity Systems: Natural circulation using buoyancy, with all terminals above the boiler.

  • Forced Circulation Systems: Circulator used to push heated water, allowing for smaller pipe sizes.

Calculation of Heat Loss

  • Heat loss calculated in BTUs per hour (BTUH).

  • Factors affecting heat loss include:

    • Building materials

    • Windows and doors

    • Outdoor temperature vs. indoor temperature

  • Common calculation methods: IBR method and Weil McLean's EZ Loop.

Sizing and Selection of Equipment

  • Key steps involve determining heat loss to select boiler and baseboard size.

  • Boiler Selection: Must match or exceed total adjusted heat loss in BTUH.

  • Baseboard Selection: Based on average water temperature and flow rate.

Boiler Components and Accessories

  • Safety Relief Valve: Prevents excessive pressure build-up.

  • Boiler Gauge: Measures temperature and pressure.

  • Limit Control: Maintains water temperature settings.

  • Circulator: Moves water throughout the system.

  • Expansion Tank: Compensates for water expansion.

  • Air Control Fittings: Release air to maintain system efficiency.

  • Fill Valve: Fills boiler with water.

Types of Piping Systems for Hot Water Heating

  • Series Loop: Continuous loop from supply to return; simple but has temperature drop issues.

  • One Pipe: Single main pipe with risers; can regulate flow better than series loop.

  • Two Pipe: Two main pipes (supply and return); allows even flow.

  • Radiant Panel: Pipes in floors, walls, or ceilings act as terminals.

Design Steps for Hot Water Heating System

  1. Calculate heat loss for the entire home.

  2. Select type and size of heat distribution units.

  3. Choose the correct size boiler.

  4. Determine piping layout and sizes.

  5. Assess GPM requirements for each circuit.

Conclusion

  • Completion of this course equips one with essential knowledge on hot water boilers, heat loss calculations, equipment sizing, and system design.

  • Encouragement for continued learning and applying knowledge for increased proficiency in hydronic heating.