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For six weeks something that runs when it's cold outside has caused shaking of the floors. There is a transformer for the powerlines at the back of the property. Neighbors to right and left don't notice anything. What can be the cause? Thanks.

Mchris
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  • Is the transformer a big square power station type on cement or a regular one on a pole for a house? – crip659 Feb 16 '22 at 12:50
  • Lots of things can cause building vibration, also depending on type of building and HVAC system. Most buildings are not passive solar, they have some sort of system that operates to make them a comforable temperature. Lots of them involve pushing air, water or freon around the building, or both. – Harper - Reinstate Monica Feb 16 '22 at 20:15
  • Can you estimate the frequency? Is it a 50 or 60 Hz hum or is it the speed of someone hitting with a small hammer (about 5 Hz) or slower again? – Criggie Feb 17 '22 at 09:57
  • How is the building heated? Single family home, apartment, condo, townhouse? – Joe Feb 17 '22 at 15:43
  • The transformer is a cylinder on a pole. The vibration is much like driving on a dirt road. Best estimate I can give is approx. 4 times my resting heart rate. The house has a gas powered forced air furnace. Thanks for your thoughts & questions. – Mchris Feb 18 '22 at 04:15

3 Answers3

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You mention the vibration happens more often when it's cold. It could be related to the building's heating system or, perhaps, the outdoor unit of a HVAC system with an old or imbalanced fan.

Rob
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Telescope2334
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    No it cannot be related to the furnace. The vibration is constant and the heat is intermittent. – Mchris Feb 18 '22 at 03:30
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Transformers do vibrate a little due to magnetostriction. You often hear buzzing or a hum when close to a high voltage transformer, this is the transformer vibrating at the mains frequency.

The greater the current passing through the transformer, the greater the amplitude of vibration. In your case, cold weather may result in more power being drawn by the connected buildings.

For this vibration to affect your building, there must be some conduit by which the vibration can be transmitted. Transmitted with enough energy to get your floors resonating. It seems a long shot but it may be possible. When you feel your floors vibrating, check closer to the transformer, can you feel the ground vibrating?

Chenmunka
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    Fun fact: those hums usually sound at twice the mains frequency, because power goes with the square of the voltage which leads to double the base frequency. So in a 50 Hz network you hear 100 Hz. See also [Mains hum on wikipedia](https://en.wikipedia.org/wiki/Mains_hum). – Andras Deak Feb 17 '22 at 23:55
  • Thank you. When near the transformer the ground doesn't seem to vibrate the way the house does. The house has a crawl space. The only connection is the cable. – Mchris Feb 18 '22 at 03:27
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Densely packed European city center buildings (including residental buildings) sometimes have their power transformers right in their basements.

Very, very quiet 50Hz hum is sometimes audible at night on the first floor and that's it.

(I am not saying that this practice has no flaws. But the vibration is not one of them).

fraxinus
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  • Thank you. I don't know the Hz. There are cables to three different houses from this one transformer. – Mchris Feb 18 '22 at 03:28