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Heat pumps of the 1800s are becoming the technology of the future

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Re: Heat pumps of the 1800s are becoming the technology of the future

#371

Post by biofunsf »

kccqzy wrote: post #132
throw0101a wrote: post #118

Earlier quoted context omitted.

> Ducts are dead. Ducts are still needed to circulate air, especially if you want to remove stale air (e.g., bathrooms, kitchen) and bring in (filtered) fresh air (to bedrooms).

Not being snarky but why don't you just open the window for that? I have a CO2 detector that I believe is a reasonable proxy for stale air. When it goes above 1000 I simply open the windows. By the time I remember to close the windows the reading is almost always below 500.

digression: Any recommendations for a good CO2 detector?

Re: Heat pumps of the 1800s are becoming the technology of the future

#372

Post by riceart77 »

kwhitefoot wrote: post #122
ClumsyPilot wrote: post #107

Earlier quoted context omitted.

Gas boilers produce NO2, and other nasties - they do affect air quality in your house

How do they affect the air quality indoors? Don't modern (less than fifty years old) gas boilers have balanced flues so that they take in air from the outside and exhaust the combustion products outside too? Surely properly installed gas boilers always did that even without balanced flues too.

Mid-efficiency furnaces are still commonplace in the US, and they don't have sealed combustion systems - they get combustion air from the indoor space, but they vent 100% of combustion products out. High-efficiency furnaces in the US made in the past 30 years or so use sealed combustion with intake and outtake to the outside. (North American high efficiency furnaces older than about 30 years were not necessarily sealed).

But yes, the GP is full of shit. Maybe they have some other non-induced vented gas burning appliance (ie a hot water heater or gas hob), or their measurement equipment is faulty.

Re: Heat pumps of the 1800s are becoming the technology of the future

#373

Post by toomuchtodo »

EricE wrote: post #336
toomuchtodo wrote: post #303

Earlier quoted context omitted.

Mitsubishi is gold standard in cold climates. It’ll pull heat from -30F air.

There's no reason that's unique to Misubishi. My parents Fujitsu has done so.

Both brands trade off as best cold weather heat pumps in ratings/evaluations (quick Google search should confirm), they’re both fairly high quality versus competitor brands.

Re: Heat pumps of the 1800s are becoming the technology of the future

#374

Post by namibj »

rootusrootus wrote: post #137
retrac wrote: post #2

> heat pumps: electrical devices Just to be pedantic, but not exactly. The typical design in a domestic heating unit, or refrigerator is mechanical. A fluid is pumped and cyclically compressed/expanded. While electric motors are usually used, they can be driven by any source of mechanical energy; driven directly by a combustion engine is not too unusual. There are also heat pump cycles that can be driven directly wit…

> There are also heat pump cycles that can be driven directly with heat. Refrigerators based on that are relatively common here in Canada in areas without reliable grid electricity. Usually a propane or natural gas flame. Notably, the propane fridges used in RVs (which AFAIK usually use ammonia for the refrigerant) are extremely inefficient. They have the huge upside of requiring very little electrical power to opera…

They're inefficient because they skimp on a motor for a forced circulation pump. Otherwise, ammonia/water absorption chillers are quite efficient.

Re: Heat pumps of the 1800s are becoming the technology of the future

#375

Post by rolisz »

Tade0 wrote: post #237
darknavi wrote: post #203

Earlier quoted context omitted.

That can work just fine by intentionally opening windows. Having a "drafty" house is just forcing that 100% of the time (which isn't always wanted). Side note: As a US resident in an area with a ton of mosquitos, I cannot understand why other countries don't heavily use window screens. Lizards a pretty cool, flies and other flying bugs are just annoying and gross.

In Europe, outside of the south, mosquitoes are pretty tame. After spending some years in Italy I developed a partial immunity to mosquito bites. It lasted for about half a year.

Eh, in Romania mosquitoes are pretty bad. And in the last couple of years they're "cousins" came along: tiger mosquitoes. Those cause a really nasty bite

Re: Heat pumps of the 1800s are becoming the technology of the future

#376

Post by adgjlsfhk1 »

mixmastamyk wrote: post #117
ComputerGuru wrote: post #51

Earlier quoted context omitted.

I've built/retrofitted and a prototype of mechanically operated louvres with push/pull fans for air exchange in an old school building, tied to the thermostat, ac, and a CO2 detector. The idea of doing the same in my home has been taunting me for years now. Ideally you'd have two such louvres, one with a push fan in the upper floor and the other with a pull fan in the lower floor to simultaneously eject unwanted heat…

> But I agree, nothing is more infuriating than seeing the AC on and the outdoor air temperature being lower Won't cooler temps outside make the AC work more efficiently and get to the desired temp more quickly?

yes but it still will be a lot less efficient than a window

Re: Heat pumps of the 1800s are becoming the technology of the future

#377

Post by earleybird »

bthater wrote: post #332
hawaiianbrah wrote: post #307

Earlier quoted context omitted.

Wow, really? Prices seem much higher than that in Seattle. A friend got 3 handlers totaling 24k BTU for like 12 grand.

Seems to just be Seattle tax, I had to get a water line replaced in my home and the quotes were $2-7k higher than I've seen suggested in other regions. Tradework here is inflated likely by the salaries of tech workers in the city.

In my locale, trades like plumbing (including gas & hvac), drywall, roofing etc range from 1 to 1.5 what contract developers from NTT, IBM et al are billed at. In absolute terms - 110 - 140 for contract devs and trades are often "to busy" at 170.

Re: Heat pumps of the 1800s are becoming the technology of the future

#378

Post by [deleted] »

riceart77 wrote: post #367
batiudrami wrote: post #258

Earlier quoted context omitted.

Much like solar panels on the roof (which I have also heard Americans describe as an eyesore), once they are common enough your eyes just slide over them and you don’t notice.

> your eyes just slide over them and you don’t notice. Nah. There have been minisplits in the US for years , they are just not very common. Moreover they have been commonplace in Asia for decades now. They are noticeable. I personally think they look like ass. They are huge and you are blind if you don't notice them. There is a reason why ducted or recessed models are available internationally for luxury homes. It ha…

[deleted]

Re: Heat pumps of the 1800s are becoming the technology of the future

#379

Post by TedDoesntTalk »

AOsborn wrote: post #249
teruakohatu wrote: post #110

Earlier quoted context omitted.

> Ducts are dead. Ducted heatpumps are a thing here in NZ and make sense to me, not that I have used one. The heatpump sits in the roof and air is pushed into three or so rooms through ducts. If building a new house I think ducts would be the way to go.

I thought this was absolutely the solution but backtracking a little now based on experience so far. We have a two-level, five bedroom new build in Auckland which came with a single-zone ducted system. So outputs are the bedrooms plus upstairs and downstairs lounges. The vents are tidy and unobtrusive - much less space than a wall unit in each location. We're having major issues balancing the temperature across the d…

What about in-line duct fans or even register fans in the rooms that are not heated/cooled appropriately:

https://www.amazon.com/AC-Infinity-Register-Thermostat-Contr...

Appropriately placed In-line duct fans and register fans will pull the heated/cooled air where you want.

Re: Heat pumps of the 1800s are becoming the technology of the future

#380

Post by malandrew »

fifteenforty wrote: post #109

In a house I own in Melbourne, Australia, I just replaced an old gas central heating system with 3 new top of the line Daikin mini split heat pumps. The new units can heat the entire house for the same amount of electrical energy that was used to run the FAN in the old gas unit. They are crazy efficient. Ducts are dead. The Daikin Alira X is the gold-plated option and cost $8k AUD for 2x2.5kw and 1x7.1kw units includ…

The problem I have with mini splits is that they are an architectural eyesore. Are there any high quality ones designed to be built into walls discretely like cove lighting has done for lighting?
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