Taming Your Electricity Bill – Part II

Okay, here we go again with another article documenting our favourite techniques for keeping monster electricity bills at bay in your vacation rental home. If you missed our first instalment on this topic please take a look at our previous post. I’ll put a link to it at the bottom of this page.

As we discussed in our previous article, the biggest contributor to monster electricity bills are guests who can’t fathom the idea that A/C units can be turned OFF as well as ON. That said, improper pool pump management isn’t far behind. The average pool pump uses between 1.5 kW and 2.5 kW per hour to run which puts them in the same family as your A/C units for energy consumption. The difference here is that preventing overuse of your pool pump is entirely within your control.

You’re Probably Running Your Pool Pump Too Much

Most pool owners run their pumps WAY more than they have to. If I had a cordoba for every time I’ve heard “my pool pump needs to run for 8 hours a day”…well, I’d have enough to buy a beer. Somewhere along the line someone let slip this pearl of wisdom but what history failed to record is that this person was probably talking about a public pool. Or a pool that sees constant daily use. Who knows. What I do know is; they were wrong. At least as far as the average residential pool is concerned.

Even if the pool in your vacation rental home sees regular use, your pool pump only needs to run long enough each day to circulate all the water in your pool through the filter once. For most residential pools this means about 4 hours of pump operation per day. Not 8 hours. It’s almost never 8 hours. Just stop doing it.

Four hours is a good rule of thumb but a couple of quick calculations will give you the exact time it will take your pump to circulate the water in your pool. Before we start you need to know the flow rate for your pool pump and the number of gallons of water your pool holds. The flow rate depends on the size of your pump and a bunch of other things but you should be able to find it in the documentation that came with your pump. If you can’t find the flow rate for your pump here’s a table of average flow rates by horsepower for a fixed speed pool pump.

0.5 horsepower pump = 70 gallons per minute

1.0 horsepower pump = 80 gallons per minute

1.5 horsepower pump = 90 gallons per minute

Assuming you have a 1.0 horsepower pump and a 15,000 gallon pool, here is how the math works out. Just swap out the values from your own setup to find out the optimal runtime for your pool pump.

15,000 gallons / 80 gallons per minute / 60 minutes per hour = 3.13 hours.

Using these numbers, you would have to have a 38,400 gallon pool before you’d need to run your pump 8 hours a day! Unless Shamu (famous killer whale) is a regular guest at your house, you probably don’t have a 38,400 gallon pool in your vacation rental home.

38,400 gallons / 80 gallons per minute / 60 minutes per hour = 8.00 hours.

Now, before you all start writing scathing comments about how I don’t know anything about YOUR pool or accusing me of needing a mountain of chemicals to keep things clean under these conditions, please understand that you’d be wrong. We have managed swimming pools at 12 different vacation homes in a tropical climate and all while using a minimum amount of chemicals.

Also, we have a pool whisperer working with us. For more than 10 years he was the guy that everyone in town called when they lost their pool. He’s part of the Mango team now but, in our humble opinion, he’s still one of the best resources on how to keep a pool clean and ready for guests. His 1000’s of hours of experience across 100’s of pools are proof that his system works. Calculate the number of hours you need to run your pump using the formula above and round up to the nearest hour. Pay attention to your pH and chlorine levels and clean your filters regularly. Your pool will be fine and you could end up cutting the cost of running your pool pump in half.

Our pool whisperer also says you should buy a timer for your pool pump. Who are we to argue?

Other Appliances to Keep an Eye On

Washing Machine (2.3 kWh per load) and Electric Dryer (2.5kWh – 4.0 kWh per load): We specialize in short term vacation rentals so most of our guests show up with enough clothes for their stay without needing to do laundry. For this reason, we recommend not offering washers and dryers in your vacation rental home. If you need to have laundry machines onsite, make sure they are locked away somewhere that your guests can’t see them. Nothing creates the need for freshly laundered socks faster than free access to a washer and dryer.

Old Refrigerator (150 kWh per month) vs. Energy Star Refrigerator (35 kWh – 60 kWh per month): If you have purchased a refrigerator in the last decade then it more than likely has an Energy Star rating. However, if you are hanging on to one of the older models in the hope it might come back in style, it’s time to move on.

Toaster Oven (0.75 kWh per hour): Some of the smaller apartments we manage don’t have room for an oven so the owners opted for a toaster oven instead. The problem is that the toaster oven gets used to cook everything from toast to roasting a chicken. Instead, buy a toaster (0.66 kWh per hour) and, if you really need one, a microwave (1.44 kWh per hour). Both are more efficient at doing what they were designed to do than a toaster oven. Sure, perfect cheese toast where the cheese is both melty and crispy on top is harder to make but your electricity bill will be smaller.

Hot Water Heater (with or without a tank): The debate between the merits of standard hot water heaters (with a tank) and tankless or on-demand hot water heaters never seems to end. When it comes to electricity usage the pro-tankless people probably have the edge but it really depends on how much hot water you are using each month. The more hot water you use, the less savings you’re going to see from a tankless system. It’s a physics thing. Whichever system you use, make sure to shut it off at the breaker if you’re not going to have guests for a while. Every bit helps.

Go Solar

Finally, if you really want to eliminate monster electricity bills, go solar. We live in a never ending summer here in Nicaragua so solar power is a great year round option. It all comes down to your expected return on investment though. A reasonable solar panel setup will cost you about $7000 to $10,000. If it saves you $200 per month then an $8500 system will take 3.5 years to pay for itself. At our house, where we don’t rent to guests, our electricity bill is usually about $40 a month. At this usage level it would take over 17 years to make the investment worthwhile. Although we’d love to reduce our footprint, this is why we are still on the grid.

One thing you can do if you don’t want to go “full solar” is get a small solar setup just for your pool pump. Because you are only running your pool pump 4 hours a day you don’t need to store any energy for when the sun goes out. If you don’t need to store energy then you don’t need to buy any batteries which makes the price on these systems very reasonable.

 

That’s it for electricity for now. Be sure to keep an eye out for our next post and another eye on your electricity bill.

 

Happy Renting!

 

If you missed “Taming Your Electricity Bill Part I” you can find it here.