An Informational Guide to Barometric Dampers (Facts & Uses)

To put it simply, barometric dampers are helpful for controlling the draft in your boiler. You can mostly find it in the boilers that have a category I vent. To understand everything more clearly, you will have to find out about stuff like a draft in detail. In this article, we will be breaking down every single aspect of a barometric damper and we’ll also give you a clear explanation of why it is useful.

What does a barometric damper do?

We’ve discussed earlier that a barometric damper helps control the draft in your boiler, well, what is a draft?

Hot air is a lot less dense compared to cold air and it also weighs lesser than the latter. This is one of the reasons hot air balloons rise above the ground. Let’s apply the same thing to the chimney and the boiler inside.

You might know that the hot air inside your chimney is produced from the boiler and the cold air is present in the boiler room or outside the boiler. As the hot air is not as dense as the cold air, it gets a great advantage and pushes the less dense or warm air around the place. While the pushing around is going on, the warm air is pushed into the stack by the cold air. Bear with me, we’ve got to the end. This act of warm air from the boiler being pushed into the stack by the cold air is the draft.

We’ve got a simple answer for what a draft regulator or barometric damper does. It basically controls the push of air from the boiler into the stack.

What is a barometric damper?

A fireplace is one of the most important things that keep you from freezing and turning into a big stone of ice (we’ll that’s a joke). In an extremely cold winter, nothing could be worse than a damaged fireplace.

A fireplace is mainly needed to heat up a room and as heat rises, you will need a chimney for the purpose of ventilation. If there is no proper ventilation, it can turn out to be a great risk for the user. And your chimney carries a certain mechanism to help provide enough ventilation. This is when a barometric damper comes into play.

A barometric damper is one of the mechanisms inside your chimney. As we’ve discussed above, it regulates the chimney draft. As time goes by, the pressure gets built up in the ducts of your chimney, and the barometric damper releases that pressure. A barometric damper is also very helpful in times of fire and opens up which allows the fire to be contained before anything bad happens.

What is a barometric damper used for?

To put all of the miscellaneous stuff we’ve talked about into place, let’s discuss why a barometric damper is important and why you should use it?

As we know by now that a barometric damper is used to control the draft in your boiler, so you may ask, why do I need to control the draft? When there is too much draft inside your boiler, it drastically decreases the efficiency of your fireplace which in turn increases the cost of using it. Along with that, an excessive draft is dangerous and can raise the temperature of your chimney above normal.

On the flip side of the case, a very little draft is also dangerous and can result in the production of carbon monoxide in the worst cases. Your chimney draft varies tremendously and it can turn out to be extremely dangerous if it raises or decreases a little. So, in the search to find a way to stabilize the chimney draft, barometric dampers came into existence.

Barometric damper types

While looking for a barometric damper, you look at two kinds of those. One is the single-acting barometric damper and the second is the double-acting barometric damper. Now, let’s take a look at what they do differently.

Single-acting barometric dampers

When we talk about the single-acting barometric damper, the main differentiation is it only allows your damper to be able to swing in one particular direction. In case there is pressure inside the stack, the single-acting damper closes.

Double-acting barometric dampers

A double-acting barometric damper swings both ways. It also allows the spillage of flue gases when there’s a blockage of the flue which sounds kinda crazy. This is the reason you have spill switches on barometric dampers. In case there is spillage from the damper into the boiler room, the spill switch senses it and turns the burner down.

In general, single-acting and double-acting barometric dampers have their place of work. Single-acting barometric dampers tend to be used in oil-fired burners and double-acting barometric dampers are mostly used in burners that use gas.

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