In 2022, California staked out an ambitious promise: six million heat pumps installed statewide by 2030. But as months tick by, the gap between vision and reality grows more pronounced. The numbers tell their own story—just 2.3 million pumps have made it into homes so far. If the state hopes to keep its word, that leaves an average of about two thousand installs every day until the end of the decade. Given that a standard mini split installation devours the better part of a day and demands somewhere between $4,000 and $6,000 per heated zone, according to EnergySage, the path ahead looks anything but straightforward.
Mary-Ann Rau sees this challenge up close. “We’ve got to do something different,” she told TechCrunch. As co-founder and CEO of Merino Energy, Rau isn’t just making noise; she’s betting on a radical overhaul.
Merino Energy, until recently operating in the hush of stealth mode, wants to flip the script on both cost and complexity. For the first time, they’ve pulled back the curtain on their creation: the Merino Mono. It’s a compact, unified heat pump unit—priced at $3,800, with a promise of installation so swift it scarcely interrupts your afternoon. Just one hour, in and out.
Rau’s no stranger to product launches; she’s stood on Apple’s stage and introduced AirPods to the wider world. She’s also spent time at Quilt, another heat pump startup delving into the home electrification space. Living in San Francisco, Rau decided to electrify her own house, equipping it with solar panels, an induction range, and an EV charger. Everything seemed manageable—until she hit the wall, so to speak, with heat pumps. The costs staggered her. “I had total sticker shock,” Rau recalls. “If I couldn’t afford it—and I recognize my privilege—then for most Californians, it’s simply impossible.”
So, what makes Merino’s solution different? Traditional heat pumps divide themselves in two: an interior heat exchanger paired with an exterior condenser, linked by copper and filled with refrigerant. That means complex installs, new circuits, and outdoor hardware—barriers that often turn off homeowners entirely. Merino’s Mono shrinks the whole affair into a single unit, no larger than a typical radiator, designed to fit under a window. You just plug it directly into a normal 120-volt outlet—no electrician needed. “If your microwave can handle the outlet, so can the Merino Mono,” Rau says.
Naturally, the Mono comes loaded with the accoutrements expected of a modern heat pump: Wi-Fi connectivity, occupancy sensing, and smart coordination when multiple units operate in the same home. Rau even hints at a near-futuristic integration with Oura Rings—if you slip into REM sleep, the Mono quietly lowers the temperature by a few degrees for optimum rest.
Installation is stripped down to basics. Workers carve two small holes in an exterior wall—one for intake, one for exhaust. The unit’s inner loop draws air across condenser coils, pumping refrigerant through a heat exchanger. Meanwhile, a separate loop pulls conditioned air from the room. Outside, only the intake, exhaust, and a narrow condensate pipe are visible, keeping the building’s facade uncluttered.
By bringing every component indoors, Merino slashes labor time and sidesteps the headache of linking indoor and outdoor equipment. “Labor is a huge part of the expense,” Rau points out, “especially when you have to braze pipes or fill with refrigerant on site.”
This all-in-one design does involve a tradeoff. In squeezing everything inside, some efficiency is lost. The Mono delivers a SEER2 rating of 15.2—notably less than Quilt’s two-zone setup, which scores 25. For sprawling suburban homes, outdoor condensers still win on raw performance. But Merino’s focus is sharper: dense apartment complexes, compact city condos—settings where space is tight and installation needs to be fuss-free. The company has already broken ground, installing 48 units at the Civic Center Apartments in Richmond, serving low-income residents as a real-world testbed.
For now, Merino is focused on California, though plans are seeded for expansion into states like Oregon, Washington, and Hawaii. Six installers have signed up between the San Francisco Bay Area and Los Angeles. Preorders are already being taken for deliveries later this year.
Rau’s vision is straightforward: simplification is the engine for scale. “The less time and hassle it takes to install a heat pump, the faster we can get them into people’s homes,” she says.
If Merino’s model delivers on its promise, those daunting statewide targets might just start looking realistic after all.
