Work curiosities episode #1

The case of the heat pump

PSJoules
PowerSage
Published in
3 min readDec 21, 2016

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Back in 2015, we took on several pilot apartments. We put sensors in the circuit panels, let them run, and then retrieved data by hand monthly. The goal: to prove our worth, and start testing our tracking abilities.

During one pilot, we monitored a resident’s heating and cooling. We were able to see the apartment unit’s furnace (the indoor fan and emergency heat) independent from their heat pump.

Now, typically, these two systems work together. The furnace fan and heat pump operate simultaneously, one circulating the air the other puts out. With our tracking, you can see them switch on one after the other.

Here you can see healthy heating operations. The fan switches on directly after the heat pump pushes hot air out. Just like it should.

Imagine our interest when that wasn’t what we saw in the pilot apartment.

During the first month of monitoring, our sensors weren’t tracking any electrical use for the heat pump. Now, we might have diagnosed this as a thermostat switched to use emergency heat only. Except, the pattern and total energy used for heating weren’t consistent with that theory.

And here you can see very unhealthy heating operations. You can see the fan switching on several times. But, where’s the heat pump?

So, what were we seeing? Heat was obviously coming into the resident’s apartment somehow. The furnace fan wouldn’t have kicked on otherwise. But, why wasn’t the heat pump showing energy use, then? Where was the heat coming from?

The pilot resident took the data we provided to the maintenance team. Convinced of a problem, they set out to investigate. And what did they find? The heat pump of a vacant unit had been wired into the pilot apartment!

Whenever that vacant unit was cold (which you can guess was a lot of the time), it would end up sending heat to the pilot unit. So, the pilot was never cold, and the vacant unit was running its equipment constantly. In effect, management was paying for the heat of a vacant unit on top of the expenses for one of their residents.

Thankfully, property management was able to correct the problem. Imagine if they had been without real time energy tracking? How would they ever catch such a problem? Imagine the costs management had already incurred, and would have continued to pay. Management would pay rising utilities, the resident would pay decreasing utilities, and no one would know why.

When key players lack insight, incidents become disasters. That’s what we want to prevent. We want to give our customers the answers they need, when they need them.

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PSJoules
PowerSage

Writing bite-sized articles on technology, sustainability, and PowerSage discoveries!