How To Install A Plate Heat Exchangers To A Domestic Hot Water Tank

Summary

In this video, Jeff from Alternative Heating and Supplies demonstrates how to install a plate heat exchanger on a domestic hot water tank. He explains how to select the right size heat exchanger based on household size, detailing the process of connecting the exchanger using lead-free brass or copper, and explains the principle of thermal pressure siphoning to efficiently heat water. Jeff also emphasizes the importance of using high-quality materials to ensure longevity and reliability. The video covers common questions, including the priority of heating domestic hot water over other heating systems.

Takeaways

• 😀 Choose a 10-plate heat exchanger for 2-3 people in a home, and a 20-plate exchanger for larger households of 4-6 people to ensure quicker and more efficient heating.
• 😀 The plate heat exchanger should be installed on the cold water side of the domestic hot water tank for optimal heat transfer.
• 😀 Use unions (preferably lead-free brass) to connect the piping for easy installation and maintenance.
• 😀 A thermal pressure siphon is created when hot water from the boiler heats the exchanger, building pressure that neutralizes with the cooling water in the tank to balance temperature and pressure.
• 😀 The plate exchanger works without a pump, relying on thermal pressure to circulate water and heat the tank to about 130°F naturally.
• 😀 Always use high-quality materials like lead-free brass or copper for plumbing to ensure safety and long-lasting performance in your domestic hot water system.
• 😀 The domestic hot water should always be heated first, before heating the house through the boiler or hot air furnace, to prevent noticeable temperature changes during showers.
• 😀 A 20-plate heat exchanger offers better longevity and durability, lasting the lifetime of the boiler if installed correctly, compared to cheaper, lighter alternatives.
• 😀 Proper installation ensures that when the plate exchanger isn't in use, water will continue flowing through it without interfering with the system's function.
• 😀 In a properly installed system, the domestic hot water tank's coil system will only activate when the boiler is no longer heating the water, making it energy-efficient.
• 😀 Plate exchangers can be used for a variety of applications beyond hot water systems, including heating and cooling for other systems like diesel or refrigerants.

Q & A

What is the primary purpose of a plate heat exchanger in a domestic hot water system?

The primary purpose of a plate heat exchanger is to transfer heat from a boiler or alternative heating system to the domestic hot water tank, warming the water without needing a circulation pump. It uses a thermal pressure siphon to circulate hot water naturally.

How do I choose the right size plate heat exchanger for my home?

For 2-3 people in a household, a 10-plate heat exchanger is usually sufficient. For larger families (4-6 people), a 20-plate heat exchanger is recommended for faster heating and better performance.

Why is it important to use lead-free copper or brass fittings in a plate heat exchanger installation?

Using lead-free copper or brass is essential for safety, as these materials prevent contamination of your domestic water supply. This is especially important since the system is connected to water you will drink and bathe in.

What happens when the plate heat exchanger is installed correctly?

When installed correctly, the heat exchanger will automatically warm the domestic water without the need for a pump. The thermal pressure siphon effect allows water to circulate and heat up the tank even without active circulation.

What is a thermal pressure siphon, and how does it work in the system?

A thermal pressure siphon works by creating a natural pressure difference between the hot water and cold water. As the hot water from the boiler heats up and expands, it creates pressure, which circulates the cold water through the exchanger and heats it up.

Why should the domestic hot water be prioritized over heating the boiler or other systems?

Domestic hot water should always be prioritized because a slight change in temperature will be immediately noticeable in showers. If the water temperature drops a few degrees in the shower, it can be a significant inconvenience, while slight temperature changes in the home heating system will go unnoticed.

How does the plate heat exchanger operate when the boiler is not actively running?

When the boiler is not running, the plate heat exchanger still allows water to flow through it, slightly warming the domestic hot water tank. The system will only use the heating coil in the tank when the water temperature drops significantly or when the boiler resumes heating.

What is the benefit of using a heavier-grade plate heat exchanger in this system?

A heavier-grade plate heat exchanger is more durable and built to last longer, reducing the need for frequent replacements. While it may slightly reduce efficiency, the longevity and quality are more important, especially for systems that are used over the long term.

What type of boilers can work with a plate heat exchanger for domestic hot water?

A plate heat exchanger can work with any type of boiler, including wood boilers, coal boilers, or any other alternative energy heating system. It is designed to integrate easily with various types of heating systems.

Can a plate heat exchanger be used for purposes other than heating domestic hot water?

Yes, plate heat exchangers can be used for various applications, including heating or cooling processes, warming up diesel fuel, or transferring heat between refrigerants and other substances. However, those used for domestic hot water should meet specific safety standards.