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How Does My Hydronic Hot Water Heating System Work?

March 10, 2014

Four Zone High Efficiency Heating SystemHow Does My Hydronic Hot Water Heating System Work? Your asking me? It’s your system.

No I’m kidding. I will be more than happy to walk you through the workings of this type of heating system. With a background that spans the last 40 years working on every kind of heating system you could imagine, I have come to enjoy jotting down the ins and outs of what I’ve learned about this common method of controlling the climate of our homes.

Hydronic heating systems are automatic. Once the thermostat is set where you want it, the controls for the zone do the rest.

One misconception that many people will have is that if the thermostat is turned higher, they are somehow ram-ping up the heating into super heater mode. This is untrue. Your zone is either on or off. The thermostat only has the ability to close the circuit or open the circuit. Your boiler receives this message and it comes on. when it doesn’t get the message anymore, or the thermostat has been satisfied, the boiler shuts off. There is no medium, just on or off.

This boiler is the heart of the system. Connected to it are manifolds that accept the piping coming and going from the rooms that are being heated. This piping is run through radiation of some kind within the room, and the convection process is used to transfer the heat from the heated water to the air within the room.

This radiation comes in all shapes and sizes today. No longer are the old bulky cast iron radiators the only type of radiation used with hot water heating. Baseboard heating units have been around for quite a while, and many radiator systems have been converted to baseboard.

New types of radiation may include designer radiators. Wall to ceiling units and towel warmer units are just a couple of the available innovations. Radiant floor heating seams to be the wave of the future. Many high-end homes with complicated multi-zone systems are using radiant heating as well as combined radiation types.

This piping forms a complete loop from the boiler through the room and back to the boiler. The water it carries is reheated over and over again. There are circulator pumps incorporated in the loop that will also come on when their respective thermostat calls, and this is how you get the heated water where you want it.

Some systems in smaller homes may be one single loop and, therefore, they will only have one thermostat and one circulator pump. Other homes with a lot of rooms will have many zones and maybe even a thermostat in every room for the ultimate in fuel saving capabilities, as well as the comfort that this type of control offers.

So the basic principle and series of operation are like this. No. 1, a call comes from a thermostat. The boiler and the respective circulator pump start. Heated water is circulated through the radiation within the room that’s calling. This continues until the room comes up to whatever the thermostat is set on. Your system then shuts off and waits for the next call.

Multi-zone systems are the same thing. The only difference is there are more calls from different places. The right pump coming on sends heat to only the calling zones. Other zones within the system will stay in standby, until their respective thermostat calls.

Being a completely automated system, hot water heating is a very convenient way to heat any home. The new innovations in style that have recently emerged within the radiation portion of this industry have only made it more popular. Designers are now able to use the radiation as a benefit of one kind or another that enhances their designs, rather then trying to hide the heater for aesthetic reasons.

Article by Robert Van Norden

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