Holy cow.

If you haven’t seen it yet, the California Heat Pump Group Buy was recently featured in WIRED. It has been surreal to see the response.

Today I want to share the next big update: we have locked in our equipment partners for the Summer 2026 Group Buy.

For this round, we are again working with Cooper & Hunter and MRCOOL as our primary brand partners. Most homes in this cohort will receive equipment from the newer MRCOOL VersaPro G2 or Cooper & Hunter ALTO product families, with the final selection depending on each home's engineering constraints, local supply-chain availability, and timing within the installation batch.

When making this decision, we weren’t trying to answer the abstract question of "what is the best heat pump?" We were trying to answer a much more useful question:

We are trying to make heat pumps work for 80% of existing homes in California: houses built around centrally ducted gas furnaces and sometimes central air conditioners, usually with some existing infrastructure we can reuse, and almost always with homeowners who care a lot about the final installed cost.

Here were the main criteria that shaped our decision:

There are plenty of systems on the market that meet some of these requirements. Very few meet all of them at a price that makes sense for a group buy.

That narrowing led us, once again, toward equipment made by Midea and sold in the U.S. through partners like MRCOOL and Cooper & Hunter.

If you have been reading Heat Pumped for a while, you know that HVAC brand names are not always what they seem. The short version: the name on the sticker is often not the same as the factory that built the equipment.

That matters because homeowners are often told to make decisions based on brand reputation alone. Contractors do this too. You will hear someone dismiss one brand as "DIY junk" and then recommend another brand using the same underlying parts with a different badge.

For this group buy, we cared less about the label and more about the actual equipment architecture:

Brand still matters, but mostly because brands come with distributor relationships, warranties, documentation, technical support, and spare-parts channels. Those things are really important.

One of the most interesting patterns in this cohort was that a large majority of participants already had central air conditioning. Roughly 75% of the homes which joined had existing AC, and in most of those homes, the AC was still working.

That surprised me a little. California has historically had lower rates of central air conditioning than many parts of the country. WIRED cited the figure at about 54% of California homes, and many of Vayu's typical customers are adding AC for the first time or replacing a system that has already failed.

The group buy seems to be resonating with a slightly different slice of the market: people whose current AC still works, but can see the writing on the wall.

Maybe their AC is loud. Maybe it uses a lot of electricity. Maybe their furnace is aging. Maybe they read too much Heat Pumped and now notice every outdoor unit in their neighborhood. Occupational hazard.

This is actually a very good fit for a group buy. If your system dies tomorrow, you probably want a contractor tomorrow. But if your system is aging and you can plan ahead, the economics get much better. We can batch work, coordinate procurement, schedule crews more efficiently, and select equipment thoughtfully instead of panic-buying whatever is in stock on the hottest day of the year.

That existing-AC pattern drove a lot of our equipment selection.

The first big detail was refrigerant lines.

Air conditioners have two copper refrigerant lines connecting the outdoor unit to the indoor coil: a larger vapor line and a smaller liquid line. In a typical AC installation, only the larger vapor line is insulated. Some heat pumps require both lines to be insulated, depending on the system design and where the metering device is located. I will spare you the full refrigerant-cycle rabbit hole for now, though I reserve the right to inflict that on you in a future post.

If a heat pump requires both lines to be insulated, then many existing AC line sets can’t be reused. That means more copper, more labor, and more ways for an otherwise straightforward installation to become expensive.

So we prioritized systems that can reuse the existing AC line set after proper inspection, flushing, and commissioning. This is one reason the group buy pricing looks meaningfully different for homes with existing AC versus homes without it. Existing infrastructure matters.

The second detail was power.

Most gas furnaces are powered by a standard 120V circuit. Many heat pump air handlers require 240V power. Running a new 240V circuit to an attic or closet air handler location can again add costly labor and materials. So we strongly preferred equipment packages where the indoor air handler can use the existing 120V furnace circuit in common retrofit scenarios.

The cheapest heat pump is not the one with the lowest parts cost; it’s the one that delivers a lower overall cost by avoiding unnecessary changes to the house.

The third detail was the thermostat.

A standard 24V thermostat like a Nest or Ecobee talks to HVAC equipment in a relatively simple way: call for heat, call for cool, turn on the fan, maybe stage one or two outputs. They’re fundamentally nothing more than a glorified light switch.

A communicating thermostat lets the thermostat, air handler, and outdoor unit exchange richer information, so the system can modulate more gracefully instead of behaving like old single-stage equipment. We have seen utility data suggesting that the same heat pump equipment can use substantially less energy when operated with communicating controls compared with standard 24V controls.

There was also a practical wiring benefit. Many homes we surveyed had only two or three thermostat wires in the wall. A typical heat pump setup with a conventional thermostat can need many more wires. The communicating controls used with these systems can often run over a two-wire communication connection, which makes them a much better retrofit fit.

For the Summer 2026 Group Buy, we are primarily working with:

These systems give us a strong balance of installed cost, efficiency, quiet operation, communicating-control capability, retrofit flexibility, warranty support, and local availability.

The biggest change for this round is cost. We know that upfront price is the barrier for most households. The group buy already helps because we can aggregate demand, coordinate purchasing, and create a predictable batch of work. But the equipment selected matters too.

The newer MRCOOL VersaPro G2 and Cooper & Hunter ALTO options allow us to offer similar real-world performance to the more premium systems (MRCOOL Universal and Cooper & Hunter PEAQ) we used in previous rounds, but at a meaningfully lower price point.

That is how we have been able to offer our lowest pricing ever for this round of the California Heat Pump Group Buy.

There are tradeoffs. There are always tradeoffs.

Some air handlers are physically wider. Some models have lower static-pressure capability than the highest-end equipment. Some system sizes have slightly lower efficiency ratings than the premium options we used in prior rounds.

For this cohort, those tradeoffs looked acceptable for the large majority of homes. Very few homes were so space-constrained that they required the narrowest available air handler. We also took static-pressure measurements where possible with the existing furnaces in place, and most homes we reviewed were within the capability of the lower-cost systems. For the handful that are not, we will flag the constraint and handle those projects case by case.

And on efficiency: yes, some of these systems have slightly lower rated efficiency than the more premium systems from previous group buys. But efficiency has diminishing returns. Going from terrible to good matters a lot. Going from good to slightly better matters less, especially when the price jump is large.

That does not mean efficiency is unimportant, especially in California where electricity is expensive. But the goal is not to win a spec-sheet competition. The goal is to deliver the best total value: comfort, reliability, efficiency, quiet operation, serviceability, and cost.

For this cohort, we think the selected equipment mix lands in the right place.

If you are in the Summer 2026 Group Buy, we will be reaching out over the next few weeks with more detail about the specific equipment package selected for your home.

The exact model will depend on your home's heating and cooling load, available indoor-unit space, ductwork, refrigerant lines, electrical constraints, local inventory, and installation timing within the batch. Most homes will receive one of the standard group-buy equipment packages. A smaller number will need a more tailored solution.

As promised, the equipment will include a minimum 10-year parts warranty.

We already finished the first installation from this group buy earlier this month! This is what they said about their installation:

And this homeowner had energy monitors, so we could see how little power the system draws in typical operation too!

For this particular home, because of shipment delays for the ALTO systems, we upgraded the homeowner to a Cooper & Hunter PEAQ system. The ALTO equipment is now in stock, and we expect to be in good shape for the rest of the cohort.

One thing that is easy to miss from the outside is how relationship-driven this still is. Huge thanks to Tim at Coolman Supply, our distributor for the Cooper & Hunter equipment, and to Steve at MRCOOL. Their responsiveness, support, and willingness to work with us are a big part of why we can make the group buy work.

If any heat pump manufacturers or OEM product teams are reading this, here is my unsolicited design brief.

The California retrofit market needs more ducted inverter heat pumps that can reuse existing AC line sets, offer 120V indoor air-handler options, support modern communicating thermostats, fit in narrow closets and attics, handle high static pressure, and hit a price point that makes proactive replacement attractive.

California has a goal of 6 million heat pumps by 2030. If that is going to happen, we need equipment designed for the bulk of the market: normal ducted homes where the homeowner has an aging furnace and AC and wants a sane path to electrification.

If you missed the Summer 2026 Group Buy, no worries. We have relaunched interest collection for the winter group buy.

We will be collecting interest through the end of October, with installations expected to begin in January 2027. As before, the group buy works best for homeowners who can plan ahead rather than waiting for an emergency replacement.

You can learn more and express interest at heatpumpgroupbuy.com.

The core idea is still simple: pool demand, make the work predictable, buy better, install carefully, and pass the savings back to homeowners.

Costco muffins, but make it HVAC.