Frequently Asked Questions
Are Large Heaters More Powerful Than Small Ones?
Nope! It may seem counterintuitive, but large heaters don’t necessarily heat any better than small ones.
Whatever their physical size, most space heaters in the US and Canada deliver about the same amount of heat. Space heaters top out at 1,500 watts, which is the highest safe operating load for a 15-amp household circuit. And aside from some low-power personal heaters here and there, most space heaters you’ll find on the market are 1,500-watt heaters.
What’s more, electric space heaters are all pretty much 100 percent efficient in converting that electricity to heat. Whether directly or indirectly, nearly all of that energy will eventually become heat.
So if space heaters are the same power and the same efficiency, why are some 1,500-watt heaters advertised for small rooms and some for large rooms? This likely has as much to do with marketing as science. Pretty much every ceramic, electric-coil, or PTC heater has about the same amount of juice and thus the same ability to heat a room … at least eventually.
What differs among heaters is how and where the heat gets distributed and how fast. All other things being equal, the efficacy of a heater is mostly about whether it puts the heat where you want it to go.
What Are the Different Types of Space Heaters?
Basically all electric space heaters do the same thing: They take electricity off the grid, usually 1,500 watts of it if you’re in the United States, and turn that power into heat.
The vast majority of space heaters, including ceramic heaters and PTC heaters, are electric resistance heaters. This means they run an electrical current through something that creates resistance: maybe an electric coil or maybe a specially designed ceramic. This quickly turns electricity into heat.
Most space heaters use a fan to disperse this heat out into the world, where we all live. These forced-air convection heaters tend to be the fastest at quickly raising the temperature of the surrounding air. The air then heats you. And so while this variety heats quickly, it can take quite a bit of electricity to heat up a whole room.
Oil-filled radiators, in contrast, heat up oil that circulates inside the device, which then emits heat to the surrounding room. These tend to heat up slower but offer even and lasting heat and are very quiet. These radiators operate on the same principle as steam radiators in buildings with a boiler room. And just like steam radiators, they can get really, really hot to the touch.
Radiant heaters, such as infrared heaters, operate much like the sun or a campfire: Rather than heat the air, they heat objects or people directly by radiating energy toward them. Infrared devices heat the air only indirectly, via the objects it heats— much the same way the sun’s heat radiates off baking city streets. The glow is immediately palpable as warmth, but you’ll need to be in the path of the radiation to feel it, and the thermometer might not immediately register the warmth you perceive. Infrared heaters tend to be best at making an individual in front of the heater feel a little warmer without using a lot of energy, making them a more common decision in large and lofty spaces or outside on a patio.
Though they deliver heat differently, both infrared and oil-filled heaters are subject to the same wattage limitations, and have about the same efficiency, as electrical resistance heaters.
The same cannot be said for heat pumps, a newer technology that’s expected to provide the next generation of household heat. Heat pumps don’t use energy to create heat. Instead, they move heat energy from one place to another. Accordingly, they require far less energy than other forms of heater. But household systems cost thousands to install. And while more affordable window and portable heat pumps are ramping up, they’re not yet broadly available.
Yes, but also definitely no.
Space heaters are much safer than they used to be. Modern space heaters are heavily regulated, especially regarding exposed heating elements and automatic shut-off switches to prevent overheating. But all heating devices require caution, and so do all devices that pull a lot of energy over long periods.
The vast majority of residential heating fires start with actual fire—specifically in fireplaces and fuel burners. But space heaters accounted for more than a thousand fires in the US each year from 2017 to 2019, according to the US Fire Administration. Though this accounted for just 3 percent of heating fires overall, these led to more than 40 percent of fatalities, in part because portable heaters tend to be placed precisely where people are and because the resulting fires are far more likely to be unconfined.
So treat your space heater with the caution and wild skepticism that it deserves. See WIRED’s Guide to Space Heater Safety for a full rundown about how not to start fires or cause othr hazards. Our guide follows recommendations from federal experts at the the USFA and the Consumer Product Safety Commission (CPSC), as well as the Association of Home Appliance Manufacturers (AHAM).
But for the short version:
Don’t leave a space heater unattended. “Unattended” includes sleeping, y’all! Might we suggest a wonderful down comforter instead? When possible, safety experts also recommend you don’t leave a portable heater running unattended in a room with a baby, nor a person with mobility issues. The risk isn’t just fire but hyperthermia.
Plug your heater directly into the outlet. Don’t use extension cords or power strips with space heaters, lest you build up too much electrical load and risk a fire.
Don’t plug another appliance into the same outlet or circuit as the space heater.
Place a space heater only on the floor, on a level surface. Heat rises. You don’t need to prop up a heater on an unstable chair or table.
Keep your heater at least 3 feet from flammable objects. This includes bedding, drapes, furniture, clothes, papers, books. All of that.
Keep space heaters away from water and dampness, whether in bathrooms or in moist basements prone to dripping or flooding.
Read the manual. Manufacturers have good advice.
How We Tested and What We Tested
When it comes to testing space heaters, there are a few main questions: How safe is it? How loud is it? How quickly and evenly can it heat a room?
During intensive testing of dozens of space heaters, I lived for weeks in a home with the thermostat set to a chilly 65 degrees Fahrenheit.
I tested how well and quickly each device heated a medium-size room (14 by 14 feet), and also how well it heated a small seating area in a larger, open-format space. To test each heater’s thermostat and also measure the evenness of heating, I placed thermometers at three or more locations in each room, including behind the heater.
I tested the loudness of each device with a decibel meter at 3 feet away and verified power usage with a wattmeter. To see whether the heater’s exhaust put out painful levels of heat, I used an infrared thermometer to gauge precise surface temperatures. When in doubt, I put my own fingers on the line.
Finally, I tested safety features and basic durability. I looked at independent safety certifications, of course. But I also rudely knocked over each device to verify how the device’s tip-over protections functioned, if at all, and verified that the device started working again when set back on its feet.
To test overheat protection, I smothered each device with an old sheet to see whether the device shut itself off or whether it adjusted its power output to keep internal temperature low. After the device shut itseld off, I then checked how soon it could turn back on, if it ever did. (Some heaters gave up, in permanent complaint!)
If any device fails the tip-over or overheat tests, we don’t recommend it. If it’s significantly louder than 50 decibels at 3 feet, we don’t recommend it. If the heater breaks during routine operation, we don’t recommend it. Maddening rattles and squeaks are also disqualifying.
We keep on testing our favorites through the cold season and beyond, to see how they hold up over time. And, of course, we continually subject more heaters to our testing regimen to see if other devices can oust our current faves.
More Space Heaters I Recommend
Photograph: Matthew Korfhage
Vornado AVH10 for $100: Vornado has an unholy variety of models that look quite similar but have different levels of loudness and different feature sets. Some are built in America, some in China. In general, the models I’ve liked best are the ones that advertise “vortex action,” a fancy name for spinning a fan into a spiral grate oriented opposite to the action of the fan. This leads to a mostly quiet and nigh-undetectable column of warm air, directed out to the back of the room, where it scatters. The TAVH10, which is basically this model but with a timer and remote, is my current favorite, though if you need neither, you can save $30 and get this.
Photograph: Matthew Korfhage
Vornado MVH+ for $75 and Vornado VH240+ for $70: These two devices are very nearly the same device. And the previous year’s non-digital MVH was my favorite model before getting displaced by a couple newer models of Dreo and Vornado. It remains among the most silent, the most even in its heat, and among the most reasonably priced. This said, the TAV10 got a little quieter and the MVH got a little louder, and the addition of a remote and a timer makes it more attractive. This said, there are reasons to favor an analog device. Because they’re analog, the MVH and VH240 can also be regulated by a temperature-controlled power outlet in order to get the most accurate version of a thermostat.
De’Longhi Slim-Style Portable Panel Heater for $210: This electric panel heater is an interesting hybrid, with dual heat exhausts on each side but also a broad radiant heat panel. This makes for a middle ground between radiators and resistive fan heaters—heating a room much faster than a classic radiator would but still maintaining warm radiant heat over time. This said, it shares a radiator’s main fault, which is that it’s painfully hot to the touch across a large surface—but still issues the same amount of fan noise as a fan heater. Still: It may be your choice if you need to heat up a space quickly and evenly and maintain that heat over time.
Dreo MC706 for $170: New this year, Dreo’s innovative 2-in-1 fan/heater won top marks in our fan guide for its auto-shift positive temperature coefficient (PTC) technology, which moves the heater’s ceramic element aside to allow full fan airflow. Its 1,700 ft/m wind speed is a rarity among tower fans, let alone tower fan/heater combos. It’s not the strongest space heater, but it is sufficient, with five settings, 120-degree oscillation, and tip-over protection. Note that though there is a remote, there are no smart features, and it does not work with Dreo’s app.
Photograph: Matthew Korfhage
Dreo Bathroom Heater for $60: Like Dreo’s smart wall-mounted model I far prefer, this ceramic heater comes with an ALCI plug for safe use near water. I prefer to keep bathroom heaters away from the floor, but not all bathrooms have mountable wall space. This remains a possible, though not ideal alternative, with a somewhat janky thermostat.
Not Recommended
Pelonis 16-Inch Space Heater for $65 and Pelonis 23-Inch Space Heater for $70: Both of these towers heated up quite quickly. Both were also enormously hot at the surface of their vents, with relatively little shielding from the visible heating elements. The 23-inch was significantly quieter than the 16-inch, however.
Photograph: Matthew Korfhage
Vornado VMHi600 for $200: This large cube was about as quiet as the AVH10, staying below 60 decibels, but its vent got quite hot—about 130 degrees Fahrenheit. Other Vornado models perform far better at a far lower price.
Photograph: Matthew Korfhage
Vornado Velocity Cube 5S for $100: This cube’s outer housing stayed quite cool, and the fan functionality is welcome. But its surface vent got a little hot, and the fan was a bit on the noisy side compared to other Vornados.
Vornado Velocity 5R Whole Room Heater for $125 and Vornado VHEAT for $160: Our top pick MVH from Vornado is one of the quietest space heaters I’ve tested. These were two of the loudest. The 5R topped 70 decibels. The vintage-looking VHEAT is quite lovely, but it’s also a bit of a noisemaker.
Lasko MyHeat Mini for $40: This little thing looked cute, and I thought it would be a nice desktop or under-table personal heater. But even with its low output at 400 watts, the vent got way too hot to want it anywhere near your laptop or papers.
Photograph: Matthew Korfhage
Lasko 22-inch Oscillating Tower With Remote for $80: This one failed our tip-over test when we knocked it over, blasting heat endlessly into the rug until it overheated and sent a burnt-plastic smell into the air. It did restart hours later, meaning this shutoff was a safety feature. But this tower’s a bit too tall and tippable to risk repeating these events often.
Honeywell 2-Position Heater for $45: This compact, simple, analog heater was a nice enough idea, able to rest vertically or on its side. Lord, it’s loud when its fan is in operation, though.
Honeywell Compact Ceramic Tower for $47: This Honeywell performed well in terms of fast heat and safe surface temperature. Its fan wasn’t too loud either. But the one we received had a maddening squeak each time the tower oscillated fully counterclockwise.
Gone but Not Forgotten
-Reviewer-Photo-SOURCE-Matthew-Korfhage.jpg)
Photograph: Matthew Korfhage
Vornado Sensa Cribside Heater: I loved the idea behind this Vornado Sensa Cribside Heater when I tested it: A space heater with an external temperature sensor, with therefore accurate temperature management (hard to find among space heaters!) But it’s disappeared from Vornado’s website, and has dwindled on retail sites. It’s no longer available on Amazon, but if you see it on sale at another site, I still like it.
Also tested but discontinued: Morento 26-cm Heater, Morento 40-cm Heater, Dyson HP07, many models of Vornado before the brand’s 2025 refresh.
Power up with unlimited access to WIRED. Get best-in-class reporting that’s too important to ignore. Includes unlimited digital access and exclusive subscriber-only content. Subscribe Today.
Source link
#Tested #Dozens #Space #Heaters
![Mercor’s Brendan Foody calls out Sequoia over ‘dual-pricing’ valuation tricks | TechCrunch
In recent days, founders and founders-turned-investors took to X to share horror stories about being mistreated by VCs. Their complaints ranged from VCs falling asleep during pitch meetings to investors suggesting a founder fire a co-founder.
Brendan Foody, co-founder of the AI talent platform Mercor, which was last valued at billion, went so far as to call out Sequoia, arguably one of the most elite VC firms in the world.
“The “sequoia scam” is worse than a single horror story,” Foody wrote on X. “in the last 6 [months] ive seen a half dozen rounds where sequoia invests in 2 tranches. everyone pretends they only did the higher valuation. founders misrepresent this to their employees & then shop it to angels too.”
TechCrunch has previously reported on VCs investing in the same round at different valuations. Under this mechanism, the lead VC firm invests a significant chunk of its capital at a lower, preferential valuation, while putting a much smaller portion of capital in at a drastically higher price. The massive “headline” valuation that gets announced manufactures the perception of a dominant market winner, masking the fact that the lead investor’s actual average entry price was significantly lower.
The disparity can be stark. For example, when the AI-driven IT helpdesk startup Serval announced a million Series B at a billion valuation, the announcement didn’t tell the whole story. According to The Wall Street Journal, Sequoia’s actual lowest entry point valued the company at just 0 million — less than half the headline figure. The gap between those two numbers is the gap between perception and reality that Foody is pointing at.
Serval isn’t alone. At Aaru, a startup that uses AI to simulate user behavior for market research, lead investor Redpoint backed the company at a 0 million valuation despite an announced billion headline price.
Sequoia’s Shaun Maguire pushed back on Foody’s characterization directly. “TBH I have seen some of this behavior but I think it’s unfair to call it the ‘Sequoia scam,’” Maguire wrote in response to Foody on X. “This has happened approximately five times during my seven years at Sequoia. What happens is other investors are willing to pay a high price for a hot company — usually AI — at multiples above what we’re willing to pay. So we try to decouple the company-building relationship with our partner from the capital, and this leads to two tranches at different valuations in close succession.
“I’m not aware of anything shady here,” Maguire continued, “but if you’ve seen it I’d love to know. VC is a repeated game, so it just doesn’t make sense for us to try to mislead people. And if anyone has, I’d love to know. And in general, congrats on the success of Mercor — it was a miss for us.”
Maguire’s response frames the practice as a market reality rather than a deliberate maneuver — Sequoia, he suggests, is simply unwilling to pay what competitors will pay for the hottest deals, so it structures its participation differently. Whether that explanation fully holds up depends on a question Maguire doesn’t address: what founders are telling the people who don’t already know about the lower tranche.
Although Sequoia appears to use this pricing mechanism most frequently, Foody acknowledged it isn’t the only firm using this tactic. And while the dual-pricing structures certainly inflate a startup’s perceived worth and help attract top talent, calling the practice a “scam” may be going too far.
That’s because employee stock options should theoretically be priced based on the blended value of all tranches — not the headline number — according to Jason Woo, partner in valuation and financial modeling at Armanino, whose firm provides the independent 409A appraisals startups use to set option prices. A 409A is supposed to reflect a company’s fair market value, giving employees a strike price that’s insulated from whatever valuation gets announced in a press release.
There’s a catch: 409A valuations are widely understood to skew low. Because a lower strike price means a smaller tax bill for the company, there is a structural incentive to keep that number down. The appraisal that’s supposed to protect employees from an inflated headline valuation is also, by design, not trying particularly hard to reach the top of the range.
The angel question is more complicated. Unlike employees, angels are writing checks, not receiving options. There is no independent appraiser standing between an angel investor and whatever number a founder chooses to share.
The dual-pricing structure is just one of way VCs and founders game the perception of success in a hyper-competitive market. Another, more pervasive tactic involves manipulating or outright overstating annual recurring revenue (ARR).
The VC Niko Bonatsos, a longtime veteran of General Catalyst who more recently founded Verdict Capital, addressed this issue during one of TechCrunch’s events in Athens last month. “We [at Verdict] mostly invest before metrics, before product, before the company [has fully taken shape] but I do have a past portfolio, and sometimes the conversations are telling. I’ll get a call or an email with a very high ARR number. I’ll think: I didn’t remember that company doing so well. So I reach out to the founder: ‘What happened? Why are the numbers so strong?’ And the answer is: ‘Oh yeah, it’s 365 times the revenue we made yesterday because one of our campaigns hit.’ So yeah, some of these terms have lost meaning.”
Foody declined to comment further. Sequoia didn’t immediately respond to a request for comment.
— With additional reporting from Connie Loizos
When you purchase through links in our articles, we may earn a small commission. This doesn’t affect our editorial independence.#Mercors #Brendan #Foody #calls #Sequoia #dualpricing #valuation #tricks #TechCrunchMercor,Sequoia Partners,Valuations](https://i2.wp.com/techcrunch.com/wp-content/uploads/2024/11/GettyImages-1258486979.jpg?w=1024&ssl=1 "Mercor’s Brendan Foody calls out Sequoia over ‘dual-pricing’ valuation tricks | TechCrunch
In recent days, founders and founders-turned-investors took to X to share horror stories about being mistreated by VCs. Their complaints ranged from VCs falling asleep during pitch meetings to investors suggesting a founder fire a co-founder.
Brendan Foody, co-founder of the AI talent platform Mercor, which was last valued at billion, went so far as to call out Sequoia, arguably one of the most elite VC firms in the world.
“The “sequoia scam” is worse than a single horror story,” Foody wrote on X. “in the last 6 [months] ive seen a half dozen rounds where sequoia invests in 2 tranches. everyone pretends they only did the higher valuation. founders misrepresent this to their employees & then shop it to angels too.”
TechCrunch has previously reported on VCs investing in the same round at different valuations. Under this mechanism, the lead VC firm invests a significant chunk of its capital at a lower, preferential valuation, while putting a much smaller portion of capital in at a drastically higher price. The massive “headline” valuation that gets announced manufactures the perception of a dominant market winner, masking the fact that the lead investor’s actual average entry price was significantly lower.
The disparity can be stark. For example, when the AI-driven IT helpdesk startup Serval announced a million Series B at a billion valuation, the announcement didn’t tell the whole story. According to The Wall Street Journal, Sequoia’s actual lowest entry point valued the company at just 0 million — less than half the headline figure. The gap between those two numbers is the gap between perception and reality that Foody is pointing at.
Serval isn’t alone. At Aaru, a startup that uses AI to simulate user behavior for market research, lead investor Redpoint backed the company at a 0 million valuation despite an announced billion headline price.
Sequoia’s Shaun Maguire pushed back on Foody’s characterization directly. “TBH I have seen some of this behavior but I think it’s unfair to call it the ‘Sequoia scam,’” Maguire wrote in response to Foody on X. “This has happened approximately five times during my seven years at Sequoia. What happens is other investors are willing to pay a high price for a hot company — usually AI — at multiples above what we’re willing to pay. So we try to decouple the company-building relationship with our partner from the capital, and this leads to two tranches at different valuations in close succession.
“I’m not aware of anything shady here,” Maguire continued, “but if you’ve seen it I’d love to know. VC is a repeated game, so it just doesn’t make sense for us to try to mislead people. And if anyone has, I’d love to know. And in general, congrats on the success of Mercor — it was a miss for us.”
Maguire’s response frames the practice as a market reality rather than a deliberate maneuver — Sequoia, he suggests, is simply unwilling to pay what competitors will pay for the hottest deals, so it structures its participation differently. Whether that explanation fully holds up depends on a question Maguire doesn’t address: what founders are telling the people who don’t already know about the lower tranche.
Although Sequoia appears to use this pricing mechanism most frequently, Foody acknowledged it isn’t the only firm using this tactic. And while the dual-pricing structures certainly inflate a startup’s perceived worth and help attract top talent, calling the practice a “scam” may be going too far.
That’s because employee stock options should theoretically be priced based on the blended value of all tranches — not the headline number — according to Jason Woo, partner in valuation and financial modeling at Armanino, whose firm provides the independent 409A appraisals startups use to set option prices. A 409A is supposed to reflect a company’s fair market value, giving employees a strike price that’s insulated from whatever valuation gets announced in a press release.
There’s a catch: 409A valuations are widely understood to skew low. Because a lower strike price means a smaller tax bill for the company, there is a structural incentive to keep that number down. The appraisal that’s supposed to protect employees from an inflated headline valuation is also, by design, not trying particularly hard to reach the top of the range.
The angel question is more complicated. Unlike employees, angels are writing checks, not receiving options. There is no independent appraiser standing between an angel investor and whatever number a founder chooses to share.
The dual-pricing structure is just one of way VCs and founders game the perception of success in a hyper-competitive market. Another, more pervasive tactic involves manipulating or outright overstating annual recurring revenue (ARR).
The VC Niko Bonatsos, a longtime veteran of General Catalyst who more recently founded Verdict Capital, addressed this issue during one of TechCrunch’s events in Athens last month. “We [at Verdict] mostly invest before metrics, before product, before the company [has fully taken shape] but I do have a past portfolio, and sometimes the conversations are telling. I’ll get a call or an email with a very high ARR number. I’ll think: I didn’t remember that company doing so well. So I reach out to the founder: ‘What happened? Why are the numbers so strong?’ And the answer is: ‘Oh yeah, it’s 365 times the revenue we made yesterday because one of our campaigns hit.’ So yeah, some of these terms have lost meaning.”
Foody declined to comment further. Sequoia didn’t immediately respond to a request for comment.
— With additional reporting from Connie Loizos
When you purchase through links in our articles, we may earn a small commission. This doesn’t affect our editorial independence.#Mercors #Brendan #Foody #calls #Sequoia #dualpricing #valuation #tricks #TechCrunchMercor,Sequoia Partners,Valuations")
Post Comment