Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

news.ycombinator.com

Post reply on HN
Print view View original

581–590 of 809 posts

Re: Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

#581

Post by afterburner »

tomcam wrote: post #349
afterburner wrote: post #313

Earlier quoted context omitted.

Solar and wind prices are extremely low and still dropping. They are already cheaper than other newly built options. Coal plants have been shutting down, natural gas is now way more expensive, nuclear can't build soon enough or cheap enough. The transition in generation is happening too.

Solar and wind do not come close to handling peak loads right, especially when the weather doesn't cooperate.

Batteries and dams can be used to store energy. It doesn't have to be sunny and/or windy all the time. Excess generation capacity takes care of the issue.

Regardless, burning natural gas for heat is burning 100% fossil fuels for heat, while electricity is not generally generated 100% by fossil fuels. Using electricity is still a huge improvement even now. And if you're using baseboard heating (electric), heat pumps are way more efficient.

Re: Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

#582

Post by cmui »

divbzero wrote: post #576
cmui wrote: post #564

Earlier quoted context omitted.

Mind sharing some details of your install - equipment model/size, controls, and cost of install?

Is there a straightforward way to estimate whether a small (24 kbtu), medium (36 kbtu), or large (48 kbtu) unit would be most appropriate for a given home?

Not at the moment, working on a tool like this for the preorder site! There are btu/sq.ft. rules of thumbs that are not appropriate for heat pumps (you can easily oversize by 100%).

Re: Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

#583

Post by briHass »

liminalsunset wrote: post #468
daredoes wrote: post #271

Earlier quoted context omitted.

The desire is to have any control/knowledge you'd want to have as the creator/developer. I want to be my own mechanic, and if I'm not that mechanic I want to be able to have anyone be that mechanic. Do you want to know what the active airflow rate is? I want to know what the active airflow rate is. Do you want to know power consumption? I want to know power consumption. Do you have a way to write unique schedules/pro…

Speaking of heat pumps and granular control, I recently figured out that some Midea heat pumps (usually sold rebranded to various brands) contain two interfaces to get and set detailed information: 1) Detailed diagnostics i.e. RPMs, feeds, speeds, currents, temps etc can be read from the high voltage signal line between the indoor and outdoor unit - there is an official tool (search "Dr. Smart Midea" on YouTube) that…

Can you provide any more details on the I2C interface on Midea units?

I found some sparse documentation on Midea's (and rebadged units) Modbus-esque protocol over RS485 (aka XYE connectors), and I control it via an ESP32 on HA. From the indoor unit, the diagnostic data I could reverse engineer is limited to temp sensors (intake, indoor coil, outdoor ambient) and basic running modes. I believe the outdoor unit also has a modbus/485 that has more info, and obviously the signal wire passes some comms between the two, but Midea doesn't make this stuff public.

Re: Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

#585

Post by pkaye »

divbzero wrote: post #576
cmui wrote: post #564

Earlier quoted context omitted.

Mind sharing some details of your install - equipment model/size, controls, and cost of install?

Is there a straightforward way to estimate whether a small (24 kbtu), medium (36 kbtu), or large (48 kbtu) unit would be most appropriate for a given home?

I think the proper method used by HVAC companies is called the manual J method. I found a simplified version below but the real thing involved a whole book.

https://www.indeed.com/career-advice/career-development/manu...

Re: Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

#586

Post by Psype »

cmui wrote: post #45
z3ugma wrote: post #12

Chris, one of my biggest worries is that your startup will get acquired or go out of business and then the firmware will leave me with a $14,000 brick. What if I want to keep using the cloud-based thermostat when your servers get shut off or moved to another system, or if something like Google Nest closing down their API happens after you've exited? This is an expensive system with an expected long life, and I'd want…

I totally get this concern. Any good piece of critical home infrastructure should be able to operate without the cloud or an internet connection. Following this logic the thermostat + heat pump combination can operate fine without the cloud. You leave some optimized behavior on the table like demand response and weather response, but everything else will work (you'd have to manually enter your TOU rate plan to get th…

You can either go using open source protocols at first or at least guarantee open-sourcing most of it in case of leadership change. For reuse.

I'd go starting with it and let a community build by itself around it, tho.

Re: Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

#587

Post by eep_social »

cmui wrote: post #300
codingdave wrote: post #240

I'm all for this effort, but this is not yet a compelling story. I've never had a problem getting a heat pump installed in prior homes. So if the market value is avoiding pain in hiring contractors... I simply have not felt that pain. Asking me to pre-order something that already exists when you have no physical prototypes feels like you are jumping the gun. I do hope you succeed - I love heat pumps and want more of…

What regions have you done those heat pump installs in? There's a lot of regional variability. Thanks for the feedback!

+1 to gp

Reading the original post, I knew immediately that you were not familiar with what’s going on in the southwest, or Arizona at least. We’ve been doing heat pumps for a long time out here. Most people talk about them like they’re AC but as far as I am aware they’re all heat pumps because it does get chilly overnight in deserts in the winter.

Re: Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

#588

Post by saenns »

cmui wrote: post #564
opendomain wrote: post #559

I love startups, but the value proposition is not here. I just had a heat pump installed and it was a much better price and higher efficiency. What is the benefit of direct to consumers is you are going to charge more? What makes your heat pumps better? Hepa filtering? Smart controls? They all have that. Is the market niche esthetics? They do look nice - maybe this company is trying to be the Apple of heat pumps? Cha…

Mind sharing some details of your install - equipment model/size, controls, and cost of install?

I'm looking at this 36,000 BTU/h unit for $3,750. Pre-charged line sets make it accessible to homeowners

https://www.amazon.com/dp/B08FGLMZB8?_encoding=UTF8&aaxitk=e...

Re: Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

#589

Post by cmui »

zhoujianfu wrote: post #163

I didn’t read everything you posted, but I’ve always also wanted “central humidity”… is that possible/feasible/does it already exist? I would like a fully electric central HVAC(H) system that keeps my house at 72F AND 50% humidity.

Yep, definitely possible and done in this system. Depending on the details of your house + climate you will be limited on how high on humidity you can go in the winter. This is to prevent condensation in the structure.

Re: Launch HN: Electric Air (YC W23) – Heat pump sold directly to homeowners

#590

Post by cmui »

londons_explore wrote: post #166

Have you considered doing double-vapor injection? Ie. have a 2nd injection port on the compressor, and another valve and heat exchanger after the first? Software could then decide to use none, one, or two, depending on the desired heat output vs efficiency.

Haven't looked at that. Dictating compressor design requires some massive scale as a business, or taking on the design and manufacture yourself, which I wouldn't recommend to startups. Also, I suspect that increased vapor injection ports has diminishing returns (but I haven't done the calcs on it).
Post reply on HN