Home Improvement

Utility History

I like to collect data. It’s rarely interesting at a single point in time, but over the years, it can provide insights or show trends that I didn’t know existed.

For example, my irrigation controller is based on a Raspberry Pi. There’s a webpage for it and it has an API so I can download the actual runtime of each zone. I’ve measured the amount of water used for a minute in each zone (by watching my water meter) so I can get a rough estimate of how much water I’m using through the system overall. Some of the variability is due to the weather, but I’ve also been tweaking the algorithm to automatically adjust the watering schedules based on the forecast.

I have a similar logging system for my HVAC. I haven’t been successful in reducing these costs much as I think I had it pretty optimized to begin with.

So yes, this is geeky, but it’s also frugal. Two things that are super attractive, right?

Yard Watering

My sprinkler controller is an Open Sprinkler model and I wrote a program which periodically pulls the logs off it and stores them in a database. I was checking out my yearly irrigation water usage and noticed that I’m generally getting better every year about keeping the yard alive with less water. Obviously this is heavily weather dependent, but generally our summers are exceedingly dry so the main variation is in the start and stop of the watering season.

The y-axis roughly equates to the number of gallons used but this is far from accurate. The year to year comparisons are completely valid though.

I have similar data showing my HVAC (furnace, AC and fan) usage over the years but I’ll save that for another time. I don’t want to pack too much excitement into a single post.

Saving Money Is Cool

I’m very thankful that we added air conditioning to this house. This last Sunday it was in the mid-90s and we burned that sucker all day long. But I’m also a cheapskate at heart. I haven’t yet figured out exactly how much energy it consumes, but it’s far from free to run so I try to use it as little as possible. Here’s our basic strategy if it’s going to be warm:

  • Leave windows open the night before to cool the house down as much as possible.
  • In the morning, leave the windows open until it’s the same temperature inside as it is outside. Then close every window and close all of the blinds on the south side of the house. Turn on the AC.
  • In the evening, once the outside temp is the same as the inside temp, turn off the AC and open everything up to get free cooling from outside.
  • Run the house fan to keep the air circulating. Our vents pump more air downstairs than upstairs (they were designed for heating) so even just running the fan can cool it off upstairs.

We are PacNW wimps so we run the AC if it’s 80 or higher and we have it set to keep upstairs at 76 degrees. Our EcoBee thermostat supports multiple thermostats which is really handy in situations like this. It also has an API so I can connect to it and pull data off. I have logs of the indoor temp from each sensor along with the outdoor temp so I wrote a quick program that helps us remember when we should close the windows or open them back up. Now we get a text reminder when we need to make changes to the windows/blinds.

Here’s an example of what it looks like on a day that got up to 84 degrees. The night before, it got down to 59 degrees outside and inside it got down to 69. Around 10:30, the outside temperature got up to the same as the inside temp so we shut the windows, closed the blinds and turned on the AC. The house coasted until 5pm before the AC finally kicked on a few times until 8:30 when we shut it off and opened the windows.

Here’s a comparison to show how much of a difference this strategy can make: On Sunday, it got up to 96. By cooling the house down a lot the night before, the AC didn’t kick on until 2:35.

That night it stayed very warm so I never opened the windows until 6:30am when I got up. The house barely cooled off at all before I had to shut things up again. Monday only got up to 87 but the AC ran almost exactly the same* amount of time as the day before!

This works really well around here because even on hot days, we get a “marine push” that brings cool winds in the evenings. Another key is that we have low humidity so I only remember one or two days where we ran the AC more than normal because of high humidity.

* On Monday, I shut the AC off at 8:40pm. So to compare the two days, I took all of the AC usage up until 8:40pm on both days. Sunday’s usage was only 20 minutes less than Monday’s usage even though it was 10 degrees warmer.

Siding, Windows and Paint

Our house was built in 1990 and had the dreaded Louisiana Pacific siding. (Detailed explanation from a home inspector site.) The siding was only warrantied for 25 years and when you throw in the major defects in the design, we had large areas of our house that were really bad. We also needed new paint so it seemed like a good time to bite the bullet. Some of our neighbors have done partial replacements of the bad areas, but we’re hoping to be in this house for quite a while and I don’t like future problems looming over me, so we decided to do it all at once. We ended up going all out and adding full window replacement to the job as well. It really increased the total price, but it’s cheaper to do it at the same time as the siding versus doing it later. The windows were original too and we had a tough time even opening some of them, not to mention dealing with mold from all the moisture that accumulated inside, etc.

It’s hard to even get a contractor to call you back, but I got two bids and chose the lower priced one because multiple neighbors had a good experience with him. The job was supposed to start the first week of April and finish mid-May. The actual job started in early May and finished in … August. Ouch. We had a dumpster and port-a-potty in our driveway for a very long time. They say a job has three levers: quality, schedule and price. You get to pick two. Price and quality were our top concerns and that’s what we got. I’m very thankful to the contractor for not cutting corners when our job took way longer than expected.

If you drive past, you probably don’t notice much different about the siding (except that it’s clean!) However, I smile now as I walk around the house because I don’t see swollen, rotting siding. And it’s wonderful having windows that open with just a finger or two. But possibly my favorite thing is knowing that we don’t have this huge bill looming in our future. It was something that had to be done before we sold the house (or take a big hit on the sale price).

Now that the contractors are gone, I have a huge work list to complete to rehab the yard, but I’m excited to dig into that (pun intended). Much of it has been going well and I’m surprised at how quickly the trampled grass and bushes have been recovering.

Yard Watering Recap

We’re coming out of the dry season, and what a dry season it was. We tied the warmest summer ever (1967) and got the record for the driest summer ever (1910). Even with all that, I’m happy to say that our yard stayed green and I think I used about the minimum amount of water possible to make that happen. Here’s the data from our sprinkler system showing the cumulative gallons used by year:

The 2015 line is especially interesting. It was very hot and dry that summer too, and even with all that water, my yard died. I had the settings really dialed in this year. The key was getting the runtime for each zone set properly and then trusting the Zimmerman algorithm inside OpenSprinkler to automatically adjust those runtimes based on the previous day’s humidity, temp precipitation and the forecasted precipitation. I only overrode it once when we had a streak of weather in the mid-high 90s.

The rain came a little earlier than it has the past two years so I’ve already shut it off, at least for now. The yard looks healthy enough and the weather is wet enough that I doubt I’ll need to run it again.