Gas. The Dirty Word.

When we first began the Happy Boolo Project, we formed a philosophy of Community, Functionality, and Sustainability to guide our home renovation. We decided early on that all three facets had to work together in harmony without favoring one over the other. And for certain, remodeling with a philosophy has helped us sense check each decision we’ve made.

So when we started looking at Sustainability (in particular our overall energy model) and what our options were for remodeling the home to be as energy efficient as possible, it became clear that we needed to keep using gas.

“Keep gas?” one may ask. “I thought going entirely away from fossil fuels is what sustainability is all about?”

We’ve learned that sustainability is a holistic practice where one choice offsets another and different sets of trade-offs appear, depending upon location, need, and budget.

Therefore, we define sustainability in much broader terms than whether or not we use natural gas. It’s more about lessening our use of gas rather than eliminating altogether. But in the bigger picture, there are more ways to reduce one’s reliance upon fossil fuels than simply by getting rid of natural gas.

We have to look at our overall water usage: our WaterSense plumbing fixtures, EnergyStar washing machine, and our extensive rainwater harvesting and stormwater management design (both coming in later posts!) The way we use water lessens our reliance upon fossil fuels.

We have to look at the design of our landscape: sequestering carbon, building soil rich in microbiology with no waste, and growing a diversity of plant life that provides a renewable source of food, fuel, and fiber. The way we use our landscape lessens our reliance upon fossil fuels.

We have to look at the home itself: upgraded insulation, a tight thermal envelope, and installing solar panels to produce as much of our own electricity as possible in order to reduce our consumption of electricity from our supplier ComEd, which as seen below, mostly comes from what-most-people-don’t-define-as-renewable sources. So, the home’s design itself lessens our reliance upon fossil fuels.

(there has probably been a shift in these percentages in the past few years)

So, what were our trade-offs/choices that aligns our need for functionality with a holistic view of sustainability — and adds in the fact we live in a (very!) cold climate during the winter.

For us, that meant four things:

1) replace our gas furnace with an electric air-source heat pump/minisplit system

2) replace our gas clothes dryer with an electric dryer

3) replace our gas hot water tank with a gas tankless hot water heater

4) replace our wood-burning fireplace with a gas insert

We’ll get into particulars of the air-source heat pump/minisplit system and our electric dryer in a later post, but

Hot Water

We previously had a large natural gas-heated hot water tank, which had been replaced twice since we moved to 631 North Drury Lane in 2000. It took several minutes for hot water to course its way to our faucets and our shower heads. That was because our hot water pipes weren’t insulated. Our research revealed that a tankless hot water heater would provide the on-demand functionality we wanted. We were advised that in order to keep electrical requirements and usage under control, we needed to retain natural gas as the fuel source. Another advantage of sticking with a gas tankless heater is that it can provide a greater flow rate than an electric tankless heater — especially in our FREEZING Chicago climate where a gas heater has a slight edge over an electric heater in heating a larger amount of water faster. The result was a Navien NPE-240A natural gas tankless hot water heater.

Navien NPE-240A (NG)

“How is a gas-fueled hot water heater sustainable?” one might inquire.

A typical gas-fueled hot water heater uses atmospheric combustion, meaning it pulls in air from the room it’s in to burn natural gas to heat the water. But that air going into the combustion chamber has to be replaced with air somewhere else, and that usually means from other parts of the house. And if the house isn’t air-tight, that’s drawing in cold air from the outside during the winter. And the exhaust from burning gas? That used to go up an (open) flue pipe (atmospheric venting) directly through our utility room’s ceiling, up the walls, and finally through the roof to vent out. Doing so adds a penetration to the thermal envelope that cannot be sealed, which means, because the flue on top of the hot water heater was permanently open, we were losing warm air to the outside during the winter regardless of whether or not the hot water heater was burning gas/venting.

The Navien uses a sealed combustion chamber in order to burn the gas. It has two pipes: one draws in air from the outside and a second exhausts combustion gas to the outside. This has two major benefits: 1) no make-up air is required inside the utility room, and thus, no air being drawn into the room from other areas, contributing to overall thermal efficiency of the house and 2) it’s much safer than the open flue at the top of our previous hot water heater’s tank relying solely upon convection (I read elsewhere this is referred to “faith-based ventilation”!)

So, the end result is a sealed-combustion tankless water heater doesn’t draw in cold air from other areas of the house, thus keeping one’s heating needs in the whole house lower than using a traditional tank.

The more obvious benefit to us is the fact that with new plumbing that includes insulated hot water pipes all through the house, when we turn on a faucet or shower, the water is almost immediately hot — gone is that minute of waiting for the shower to get warm enough (and gone the wastefulness of letting all that cold-cool-warm water go down the drain).

Insulated hot water pipes

Fireplace

Our old wood burning fireplace, though a gut-wrenching decision to remove, nonetheless contributed to our home’s energy inefficiency. As almost every homeowner knows, a traditional wood fireplace draws in air to keep the fire going, and then you’re back again to make-up air and the inherent thermal inefficiency that brings—”you’re sucking all the heat out of the house!” Even keeping the flue closed as we did when not in use, it was impossible to seal it off completely, so it, too, contributed to overall heat loss in the winter.

Our solution was to install a Napoleon gas fireplace insert.

Napoleon Oakville 3 Insert in June

It’s called an “insert” because it inserts into the existing opening for the wood-burning fireplace. And just like the hot water heater, this fireplace uses sealed combustion by drawing in air through an intake vent and exhausting combustion gas through a separate exhaust vent — both built into the existing chimney. Think of it as a box within a box. I literally could not find a cutaway diagram of a Napoleon insert, so I drew one below!

The air comes in from the chimney into the sealed combustion chamber (the “inside” box). At the touch of a button on a remote, we can ignite the gas. As it burns, exhaust goes back up a separate vent through the chimney. The “inner” box heats up, causing the air surrounding it (the gap between the inner and outer box) to heat up. Then a blower fan (F)… and NOT drawn in the right position, I should add! (it’s back farther behind the firebox) draws in air from the room at the bottom of the fireplace and circulates it through the inner chamber between the inner and outer boxes, where it exits back out into the family room. And let me tell you… it was worked MARVELOUSLY during the last several weeks here in Chicago in our basement!

So, for us, by getting rid of a gas furnace and a gas dryer — but replacing our traditional atmospheric-combustion hot water tank with a sealed-combustion tankless hot water heater and replacing our wood-burning fireplace with a sealed-combustion fireplace insert — we’ve greatly lessened our reliance upon natural gas.

In an upcoming post, we’ll get into what we replaced the gas furnace with! For now, STAY WARM!