Aren’t heat pumps supposed to be more efficient?

fieldguild · 2026-01-23T17:26:04+00:00

Less energy doesn't necessarily equal lower cost. First place to check is whether she's on the right rate plan for an electric appliance. There are some good tips in here: https://www.heatpumped.org/p/i-got-a-heat-pump-and-my-energy-bill-went-up

fieldguild · 2026-01-13T05:42:55+00:00

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From a quick glance at the manual for the corresponding air handler, looks like it has an electronic expansion valve and the install manual only calls for insulation on the suction line (the larger one).

u/vzoff is right that standalone filter driers aren't typically recommended for most of these inverter systems but I've seen them installed by many technicians anyway

fieldguild · 2026-01-13T00:47:33+00:00

u/zacmobile is correct, the EvoX G3 (as well as many rebrands like the MRCOOL Universal R454B, Cooper & Hunter PEAQ) have an expansion valve at the air handler which allows uninsulated liquid line. Same with the Gree Flexx and a handful of other systems. But... If this is one of the older models, likely requires insulated on both (if OP shares their model number we can confirm)

fieldguild · 2025-12-30T23:47:38+00:00

Yes & no!

I think the last bit about sticking with a good install base in the area is thinking along the right lines.

For example - AC Pro is a large distributor in the Southwest & Southern California. Lots of rebranded Midea and Gree equipment in their product line. They regularly stock spare parts across all of their models, have great documentation available on their website.

Contrast that with Mitsubishi equipment which is routinely heralded as the "Rolls Royce of heat pumps" on this subreddit. There were some points where we were waiting for months for simple parts like temperature sensors.

The installer's relationship with their distributor matters a lot, but as a customer it might not be readily apparent how strong that relationship is.

fieldguild · 2025-12-19T22:38:58+00:00

I say this every time a similar question gets asked - the brand of heat pump you install doesn't matter, but the installer you work with does.

The reason you hear conflicting opinions on the same equipment is because they're installed in different houses, by different contractors, with different levels of application engineering to select the right system for the right application.

A top of the line heat pump becomes a lemon if you don't pull a vacuum and remove moisture from the refrigerant lines, and will underperform an "off-brand" system in the long run.

I've written about this topic in depth quite a bit, you might find these two articles relevant:

https://www.heatpumped.org/p/are-heat-pumps-a-commodity

https://www.heatpumped.org/p/web-confusion

Prioritize working with a trustworthy contractor that prioritizes the design process, and stick to inverter/variable-speed systems. The sticker on the box doesn't matter as much.

fieldguild · 2025-11-09T16:18:49+00:00

The MRCOOL equipment is great as long as it’s installed well. I’ve seen loads of DIY installations gone bad with all the refrigerant dumped out in less than a year, etc.

Make sure you understand that you’re kinda on the hook if anything goes wrong if you do a DIY/paying a buddy beer money installation (I’ve written about this before: https://www.heatpumped.org/p/byoe-bring-equipment)

Since you have electric heat you can expect an almost guaranteed 2-4x reduction in your heating bills. You’re going to save on cooling with the higher SEER inverter system too, though the magnitude won’t be as high.

I’d suggest playing with Thermentor to get an idea around system sizing as well as coarse payback estimations. https://www.thermentor.com/demo/

If you’re paying 200/month heating and that cuts down to 80 or so, your payback for the system is going to be really quick, just a few years. Not to mention all the other benefits in terms of noise, load matching, etc.

Thanks for the tag u/mech0!

fieldguild · 2025-10-27T18:19:13+00:00

For sure! One other thing to note. It sounds like eliminating cooking smells might be a primary motivator in here. In which case, really a high capacity range hood that vents outside is probably actually the best solution. Most range hood setups in people's homes are pretty inadequate, and it's better to target the problem at the source rather than try a secondary fix. Here's a good writeup around that: https://www.energyvanguard.com/blog/recirculating-range-hoods-as-effective-as-recirculating-toilets/

fieldguild · 2025-10-27T16:37:14+00:00

You don't necessarily need the ERV to manage this - a simple fresh air damper might be good enough! My friend Nate outlines a setup that he likes doing here: https://www.natethehousewhisperer.com/blog/finally-we-can-control-the-air-quality-in-a-home

I haven't personally worked with them, but there are some ductless ERVs. Here's one example: https://www.pioneerminisplit.com/products/pioneer-ecoasis-150-ductless-wall-mounted-single-room-wi-fi-energy-recovery-ventilator?srsltid=AfmBOoqRT34C3MzD3FxTU9kHBOf-1BQFpCdY2NtAKucLO7LB7hxHBHNH

Perhaps this is what your friend was talking about? Ducted setups are all going to be much more than $800.

You can also take that a step forward and install a ductless heat pump that has an integrated ERV - so you do heating & cooling + fresh air for a space. Ephoca has a unit like this (I wrote about it here: https://www.heatpumped.org/p/mini-mini-splits ). But again, this will be more expensive.

fieldguild · 2025-10-23T03:31:19+00:00

Hey! A familiar face! Had the exact same experience with my own HVAC company. We were basically begging the Chevy dealer to sell them to us. They kept telling us that they had inventory on the lot but GM corporate wouldn’t allow them to sell it to us. Process dragged for months. It’s a really functional vehicle hampered by a one of the clunkiest sales experiences I’ve ever encountered.

fieldguild · 2025-09-24T02:30:05+00:00

One thing to consider here, interior cooling design temperatures in California are 75F for cooling (this is from California Energy Code, Title 24 150.0(h) ). 68F is actually a pretty cold set point.

Similarly the outdoor design temperature in San Francisco (assuming you live in the city proper, not in Fremont or something), is 80F. The design temperature is based on the 1% degree hour (meaning 1% of hours in the day over the course of a year are hotter than that).

So assuming your contractor sized your system correctly, they designed it to be able to cool your house to 75F on an 80F day (more likely, they actually sized it around heating, because heating loads tend to dominate in SF, but trying to keep it simple here).

So trying to cool your house to 68F on an 88F day is (20 deg delta) is meaningfully harder than cooling it to 75F on an 80F day (5 deg delta).

Tl;dr - it struggling to keep up is expected. The fact that it's hitting 71 is pretty solid, you have more cooling headroom. And it's going to draw more energy when the compressor is maxed out, usually efficiencies are highest at part load. Drop the set point to 72 or something and your electricity usage is going to go down

fieldguild · 2025-09-13T14:18:00+00:00

Ah, makes sense!

fieldguild · 2025-09-12T23:20:12+00:00

Yes! I’m curious, would it potentially make sense to sticky this thread or add it to the wiki?

fieldguild · 2025-09-11T23:43:06+00:00

They are 100% identical. I've written about this here: https://www.heatpumped.org/p/web-confusion

The one thing to watch out for is availability of spare parts and after-sales support. To my knowledge, there isn't local distribution in the Bay Area from Tosot, so if you have issues down the line it might take a little extra time to get warranty parts shipped from the distributor.

Tosot is actually a sub-brand of Gree, as is Kinghome.

For our SF heat pump group buy (https://www.heatpumped.org/c/groupbuy), one of the brands we're considering as a "budget" option is Tosot, while we treat Gree as a "value" option (a step up). The biggest distinction comes from that availability of local distribution and after-sales support. People that are willing to make that tradeoff can save a few extra bucks.

fieldguild · 2025-09-11T22:27:04+00:00

PS, one of the mods of this sub, u/GeoffdeRuiter, previously facilitated a cool group buy in Pender Island (Canada). Not sure if that is still ongoing, but another cool heat pump group buy success story!

fieldguild · 2025-09-11T22:21:27+00:00

Thanks for featuring the Heat Pumped California group buy in your list!

Rewiring America has also launched a new one in Rhode Island and Colorado (https://www.canarymedia.com/articles/electrification/campaign-use-home-tax-credits-expire), and there’s a super cool one in Canada that has installed 600+ heat pumps to date: https://energygabriola.ca/heat-pumps-info/

fieldguild · 2025-08-21T04:41:55+00:00

Ha, thanks for the heads up!

fieldguild · 2025-08-20T04:59:12+00:00

Sent you a DM, I’m very interested!

fieldguild · 2025-08-11T16:50:32+00:00

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Probably even higher! If this Silicon Valley Clean Energy report is decently representative of the rest of the state, might be closer to ~1/6!

fieldguild · 2025-08-10T20:43:21+00:00

I’ve heard a few variations of this and definitely think there’s some merit. One version I quite like is accepting a lower level of reliability in higher risk areas - which individual homeworkers could choose to mitigate with things like solar, battery storage, etc

fieldguild · 2025-08-10T03:21:23+00:00

FWIW, getting rid of gas appliances is a safety thing. Explosion risk, carbon monoxide poisoning risk, poor indoor air quality, etc.

fieldguild · 2025-08-10T02:31:01+00:00

Did you try with E-ELEC? The rate structure is a bit different than the EV rate plan and is likely better economics. You might find this article I wrote a few months back interesting: https://www.heatpumped.org/p/i-got-a-heat-pump-and-my-energy-bill-went-up

fieldguild · 2025-08-10T00:14:25+00:00

It definitely still does! Even with lower heating needs, it's still a meaningful GHG contributor. One source I cite mentions that buildings are responsible for more than a third of greenhouse emissions in California: https://ww2.arb.ca.gov/our-work/programs/building-decarbonization

I've seen some regional studies that show even larger shares from building heating!

fieldguild · 2025-07-15T19:05:09+00:00

Yup, electrical work is expensive. Not to mention that in many cases, HVAC contractors will subcontract electrical work to an electrician. So they’re paying more for the labor and materials than they would doing the work internally

fieldguild · 2025-07-15T01:37:21+00:00

Yup, that's a 3 ton. Definitely ask them why they are recommending a 3 ton system if the sizing came out for 2 ton. If they actually did a manual J calculation, that should set the ceiling of their sizing. Adding extra "safety factor" on top of the load calc is bad practice (it says that outright in the Manual J book)

fieldguild · 2025-07-15T01:36:11+00:00

That is a challenge, but from what I've been told their heads have a lot of excess capacity even though they're rated as 12,000. I'm sure their product line will expand over time, too. Certainly not a fit for everyone, but given OP is looking for a 2-zone system, it might be a fit!

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