frankus

A number of newer ones are ventless (although still very much the minority in North America), but only some use an actual heat pump to recycle the heat. IME most of the cheaper ventless dryers just reject the heat (but not the moisture) into the room they're operating in.

This is still a win because it doesn't depressurize the house (any air you vent out of the house is eventually replaced by outside air, sometimes via dirty areas like crawlspaces and attics). But the heat pump ones can run off of a low-power (~1500W) circuit whereas the condensing ones typically need a higher power (~5kW) circuit.

There really ought to be a law against making cancellations any more involved than sign-ups (I understand California has something like this already), but failing that a public shit-list of companies that make it a hassle to cancel subscriptions would be a good stopgap.

I've been doing a bit of research into air-to-water heat pumps (using a conventional vapor compression cycle) as I'll be installing one soon (Bear with me—I promise I'll get to thermoelectric devices by the end).

They're currently able to replace a boiler for a heating system designed around relatively low-temperature (120°F/50°C) emitters, with lower temperatures leading to better performance (so a large radiant panel in a floor or ceiling is a good choice).

One of the underutilized capabilities they have is to do radiant cooling. The tricky part is that any part of the system that drops below the dewpoint (in whatever space it's located in) will condense moisture out of the air, likely damaging itself or things around it over time. You can address this to some degree by either modulating the heat pump or mixing/recirculating water to keep the emitters a few degrees above the dewpoint, but that limits the amount of sensible heat that you can remove from the space and doesn't do anything for latent heat (i.e. humidity).

One solution is to use an emitter (e.g. fan coil, either central or in a little wall unit like a mini-split) that has a drip tray that drains the condensate away to where it can't do damage, but the pipes leading to the emitters still need to be insulated and vapor-sealed. This isn't terribly expensive to add to a new system but could be quite expensive to retrofit into a system where the pipes are already buried into the walls.

Another approach is to keep the fluid above the dewpoint and use a separate dehumidifier that condenses moisture out of the air and releases the resulting heat into the space. This isn't ideal because you're adding an additional heat source into the space that you're trying to cool.

As I understand it, the strength of thermoelectric devices is that they're silent and relatively small, but their weakness is they're not terribly efficient, especially for cooling, and have a steeper drop-off of efficiency with increasing temperature difference between the cold and hot side.

But for dehumidification, the temperature difference is likely small (from a few degrees above the dewpoint to a few degrees below it), and also the latent cooling load tends to be a fraction of the sensible cooling load.

So the idea would be to build a device that is plumbed inline with the emitter in each room (or possibly just e.g. a bathroom or kitchen) that uses a thermoelectric device to cool a heatsink below the dewpoint (with a fan) and collects the condensate for disposal, but rejects the heat into the return pipe to the heat pump.

The advantage over a conventional fan coil-based system is that the in-wall plumbing (and indeed all of the hydronic plumbing) remains above the dewpoint, so the indoor hydronic piping doesn't need insulating or vapor sealing.

I could see this being especially useful in buildings converting from a condensing boiler to a heat pump and want to add cooling without tearing open all the walls.

If these could be rented it could be interesting for occasional road trips instead of e.g. renting a whole car.

It could also see something like this but using one of the very high energy density but non (in-situ) rechargable battery chemistries.

Any idea why they would use brushed motors? When every gram counts I would think ditching the mechanical commutator would be a no-brainer, but maybe adding another leg to the H-bridge is a bigger penalty?

I saw a video claiming that Germanic words beginning with sn- all have to do with the nose. For example “snoop”, “snob”, “sniff”, “snarl”.

Interesting n=1 experiment of a guy who lowered his fasting blood glucose from pre-diabetic to normal by restricting BCAAs: https://fireinabottle.net/how-i-both-aced-and-failed-my-oral...

How robust are these to random floating logs? They’re quite common here in the Salish Sea and have been cited as the reason that the Boeing hydrofoil project never really took off.

I have to wonder if at some point rich eccentrics will start installing CO2 scrubbers in their houses to bring the indoor concentration below 400 ppm.

My guess is that the name is from the Preston character in the 1995 Wallace and Gromit short A Close Shave, which would have premiered a couple of months before the first beta.

I feel like this is a lot more approachable with the advent of cheap mass-produced RC helicopter parts (modulating the collective pitch with the audio waveform).

(Which has me wondering if you could do some fun directional things with the sound? Of course low bass is not exactly known for its directionality)

Only loosely related, but are there any affordable non-invasive tests for past lead exposure?

I have a cluster of symptoms that are consistent with lead exposure[1], along with a lot of past activities involving lead (stained glass, old-school electric cars, soldering with lead-based solder, stripping lead-based paint), but my current blood lead levels are normal.

My neurological symptoms also flared up when I was supplementing with kind of a lot of Calcium and Vitamin D.

[1]mostly high blood pressure, somewhat high cholesterol (despite having normal BMI, sleeping reasonably well, exercising regularly) and demyelinating lesions visible on MRI (but no oligoclonal bands, negative AQP4).

A few years back spent a lot of time stripping lead paint using a heat gun and IR emitter thing ("silent paint remover"). It was definitely smelly, but I convinced myself that the temperatures were far too low to vaporize lead.

But in the back of my mind I always wondered if there was an equivalent of a eutectic mixture for the liquid/vapor phase transition.

As a sanity check I looked at it from the standpoint of a 2400-calorie diet of 100% carbs (glucose) and it works out to around 32 grams per hour of CO2, which agrees with a figure of around 1000 liters per minute to dilute it down to 400 ppm over ambient.

This may or may not apply to OPs app, but for mobile-first apps with a broad audience, having an identical appearance/interaction model across competing mobile platforms is a bug, not a feature.

Or maybe not exactly a "bug" but at least an unfortunate tradeoff because your org lacks in-house expertise on one or more of the target platforms.

The case of a single person using many apps on a single mobile platform is just so much more common than the case of a single person using your app on multiple mobile platforms that it makes far more sense to hew to the platform idioms at the cost of cross-platform consistency.

An obvious exception might be something like Slack, where it's common to use both the mobile app and the web app (either directly or via an Electron-like wrapper), but calling Slack "mobile first" is also a stretch.

Kind of obsolete now but a radio tuner where the strength of the detent is proportional to the strength of the signal.

There's actually a clever way to reconfigure the inverter electronics and (induction) motor to essentially do "regenerative braking" off of a 3-phase supply (https://patents.google.com/patent/US5341075A/en).

I'm not sure if this is so widely used as to not be worth mentioning, or if there are hidden gotchas or patent encumbrances that keep it from being widely used.

Not directly related, but a fun(?) anecdote: I worked for a dog-friendly company in Seattle for a few years in the mid 20-teens. I started out commuting from my parents' place (who dog-sat for me), taking a commuter train and then a bus. I rarely chatted with anyone on the train/bus during that period.

After a few months I managed to find a place in the city and would ride the (pet-friendly) bus with my 90-pound samoyed, who despite usually being anxious in crowds took to it really well.

Long story short, the dog was an amazing cross-class ice breaker. I'm pretty introverted, but just about every trip someone would strike up a conversation with me, and it was usually folks I wouldn't otherwise interact with.

So anecdotally, usable public transit can be a good class desegregation strategy, and taking a charismatic dog with you supercharges it.

Step 0 in the US might be enforcing laws against fake temporary tags or concealed license plates. If I had a dollar for every “thin blue line” sticker-sporting car with a barely-transparent bit of plastic over the license plate…

Seems like the illegal covers would be straightforward to enforce any time these cars are parked on public streets.

Or you could have a rule that people without overhead baggage get to deplane before everyone else.

I think it's all about the possibility to later upsell. I don't think the economics work out where it's cheaper to install something like a seat heater in every car and permanently disable for price discrimination purposes (the way you might for e.g. a CPU).

My brain can kind of rationalize this as "it makes the up-front price lower, and you can add features to your car without even visiting a dealer", but my heart definitely recoils at the idea of paying for something like that already in my possession.

If done right the stations will be in locations where having a car is more of a liability than a convenience (i.e. downtowns with lots of traffic and expensive parking).

We need “anything sketchy about this 20-page contract” as a service (for something less than the cost of retaining a lawyer).

An interesting take awhile back on this exact issue: https://jbconsulting.substack.com/p/on-shelter-futures-part-....

The fear (now largely realized) is that increasing interest rates mechanistically drive up inflation (because of how the price index is calculated in Canada), which the Bank of Canada combats by...raising interest rates.

Includes a good discussion of just how potentially screwed the housing market is.

(Also an interesting example of a market where "prices expand to fill the available money", which I have a hunch is a good indicator of a supply-constrained market).

To be fair, that's about the same with the exchange rate, but the fact that the average mortgage cost across all of Canada is the same as one of the most expensive US markets is telling.

About two tablespoons of store-bought ranch dressing will put you at the 2% number that the article suggests as the high end of preindustrial intake.

(11g of unsaturated fat in 2 tablespoons of Hidden Valley Ranch, assume soybean oil because it's cheaper, which is ~50% LA, so about 50 calories, which is 2% of a 2500-calorie/day diet)

I find a reversal test is sometimes useful when considering whether to keep something: if I didn’t already own it, would I buy it for an amount that it might sell it for.

I’ve been digging into Apple’s (existing) accessibility features last week and it made me think about what (for lack of a better term) an “accessibility first” app architecture might look like. Current app UIs are all about how to visually represent the objects you can interact with and the actions you can take on them, and then accessibility features are layered on top. (Warning: half-baked idea that’s probably been tried countless times) what if you started with semantic information about the objects and the actions you can take on them and then the GUI is just one of several interaction modes (along with voice, keyboard, CLI, etc)?

It’s also denser than water and somewhat hydrophobic so if I understand correctly it tends to settle at the bottom of aquifers.

The "Automatically hide and show the menubar" setting should really default to "Never" for notched displays, since it doesn't actually gain you any extra real-estate and just slows you down with a pointless animation.

I finally turned it off because on my (non-notched) external display it was too easy to accidentally activate, which would disable the thing in the toolbar that I actually intended to click on (and then I'd have to sit there and wait a second for it to re-hide before very carefully mousing to almost-but-not-quite the top of the screen to click my intended target).

It's in the Desktop & Dock section.