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Frugal Happy: Epic House Update

Chris and Wen tame an unruly crawlspace and install a minisplit system

Sealing and insulating the crawlspace proved to be a difficult process, certainly not suited for claustrophobic people.

Editor’s Note: This post is one of a series by Chris Stratton and Wen Lee, a husband-and-wife team living in the Los Angeles area who are turning their 1963 suburban house into an all-electric, zero-net-energy home. They chronicle their attempts at a low-carbon, low-cost, and joyful lifestyle on their blog Frugal Happy. This post was written by Wen. All photos courtesy of the authors.

Okay everyone, it’s been seven months since our last post, and we were already months behind then. Now our blog is woefully, embarrassingly out of date. Our apologies!

So, here’s our attempt at a massive catch up to bring our posts up to the present. While each of these topics deserves its own detailed post, we unfortunately don’t have time to do them all justice right now. We are happy to answer detailed questions so feel free to leave a comment or send us a message about anything you see here. You can learn about our skylight installation and wiring at our website.

Crawlspace retrofit is one nasty job

This was probably the dirtiest work of the whole renovation project. Where we live in southern California, crawlspaces are very common. They are typically nasty, dirty, drafty, and neglected.

Our crawlspace was uninsulated and vented to the outside, which meant that outdoor air could leak into our house through the floors. It was also unprotected from moisture that may seep in from external sources like rain, which in turn might result in mold and unhealthy air leaking into the house through the floor. The former was a particularly big concern, because Chris put in a ton of effort installing superinsulation in our walls and roof. What was the point of all that effort if the floor was completely uninsulated?

Chris decided to encapsulate the crawlspace. This entailed installing a vapor barrier on the crawlspace floor that wraps up the walls and the piers, and then installing insulation around the perimeter.

But first, he had to clean out the crawl space. Turns out there was a lot of crap down there, like huge chunks of old concrete from when we redid the footings to vault the ceiling.

To seal the crawlspace, we used a 15-mil Stego Wrap vapor barrier, Stego tape, and cans of spray polyurethane spray foam. First, Chris wrapped up all the footings under the house.
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Wrapping up the footings was the first job.

The roll of Stego Wrap was big. My brother Bin and our friend Johnny helped lay it out on our driveway and cut long strips that they could manage to pull into the crawl space.

We unrolled the plastic in the driveway and cut strips to be taken below.

Below you can see Chris taping together a seam to ensure that it’s completely sealed. Doesn’t he look like he’s having fun? The crawlspace has 8 inches to 13 inches of clearance and is full of ancient dirt and decomposing spiders, so you know he’s got to be extremely comfortable, dragging his stomach along the ground in dusty darkness for hours. (On the plus side, he says it’s an excellent ab workout.)

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Stego Tape helps make a good seal.

Installing rigid foam insulation is tedious enough above ground, but try doing it in a cramped, nasty crawl space. Chris installed 2 inches of rigid polyisocyanurate foam on the stem walls, and 3 inches at the rim joists. He then air-sealed the perimeter of the rigid foam using canned spray foam. This effectively brought the entire crawlspace into the conditioned space of our house (insulating it from outside temperatures).

Below is a photo of the nearly-complete encapsulated crawlspace. Now the crawlspace is no longer vented to the outside, and it’s protected from outside temperatures (which means our house is fully insulated in all directions) and also protected from external moisture issues (which means minimizing the potential for mold and rot).

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The nearly completed project.

We live in a very dry climate, so this is fine as is. In a more humid climate, though, it might be necessary to install a dehumidifier or exhaust fan in the crawlspace to make sure that moisture does not build up.

What a nasty, difficult process and not recommended for claustrophobic people. Luckily, Chris had lots of help from Bin, Johnny, and Lac, who all courageously entered the abyss of the crawlspace with him.

A new heating and cooling system

We used to heat and cool our house with an old gas furnace and a loud, inefficient central air conditioner. Chris tore these things out and replaced them with a single system: a minisplit heat pump. Minisplits provide both heating and cooling, and they are much more energy efficient than our old equipment.

Specifically, we installed a two-zone minisplit heat pump made by Mitsubishi. The system consists of an outdoor unit (which you can see below) and two indoor units (zones)—one ductless wall unit for the common area, and one ducted ceiling unit for the bedrooms. Each indoor unit has its own thermostat that can be controlled separately.
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Chris, Bin, and Johnny with the new outdoor unit.

Our neighbor Albert is a HVAC specialist and helped Chris install and test the new system (e.g. making sure there were no refrigerant leaks).

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Chris and Johnny installed the ducted unit in the hallway ceiling between the bedrooms.

Since we have three bedrooms, we needed three ducts to come out of this unit. Instead of ordering special parts (custom work is expensive), Chris decided to make his own branch transition. He bought three boots from an HVAC store and fit them into his creation.

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Instead of paying for expensive ductwork, Chris built his own splitter.

It fits the unit that’s installed in the ceiling.

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Each duct will serve a separate room.
Below is the wall unit, which is ductless and way less complicated. It conditions the common area which includes our living room, dining room, and kitchen.
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This ductless fan unit serves an open common area.

Chris ran the refrigerant lines and electrical wiring from the wall unit to the outdoor unit along the outside of the house. It’s not the prettiest arrangement, but it allows us to avoid the risk of moisture (from condensation) inside our walls.

Unfortunately, we had a bit of an electrical snafu with the outdoor unit. Somehow, while pulling the electrical wires through the wall, some wire insulation got stripped. So when Chris tried to turn on the outdoor unit for the first time, there was a short circuit and we heard a small pop inside the outdoor unit.

The unit refused to turn on. Chris spent many hours attempting to troubleshoot and fix the problem. Our friend Gavin, who has a degree in electrical engineering, even came over to try to help.

But alas, it was not fixable. Below you can see the burn marks in the circuit board of the outdoor unit. It was totally fried. We had to order a new circuit board. Once we put in the new one, though, everything worked like a charm.
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A scorched area on the circuit board tells the story.

Below is a photo showing the repaired outdoor unit, which powers the two indoor units:

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And here again is the wall unit, which heats/cools the common area of the house:
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We now have a functional minisplit heating and cooling system. Due to the improved insulation in our house and the greater efficiency of the minisplit, we are consuming way less energy to heat and cool our home than before. For example, the house’s AC system dropped from a capacity of 3.5 tons of cooling to just 1.75 tons of cooling. That means our AC electricity use has been cut in half. And it’s much quieter. We no longer burn fossil fuels for heating, and we can also adjust the temperatures for different rooms. It’s pretty sweet.

One Comment

  1. Malcolm Taylor | | #1

    Chris and Wen,

    The only part of your blog I wish I could change is that so much of the work you had to do was extremely unpleasant. Most of the tasks I do building a house are enjoyable. Hopefully over time the memory of the nasty bits fade, and the satisfaction of the result remains!

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