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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

#291

Post by kccqzy »

catiopatio wrote: post #261
kccqzy wrote: post #204

Earlier quoted context omitted.

Because presumably in this case you would want to open a window for fresh air, and simultaneously run your heating system to heat up that fresh air? I was responding to a comment that presupposes the need for fresh air. If you don't need that, feel free to close the windows then.

You do realize that “open the window and hear that air” is massively energy inefficient, right?

I don't know; is it more energy inefficient than having a fresh air intake via a duct? Maybe they are comparable in the absence of a heat recovery ventilation system (mentioned by a sibling comment upthread)?

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

#292

Post by mvnuweucxqokii »

tomcam wrote: post #277
mvnuweucxqokii wrote: post #163

Earlier quoted context omitted.

Not to be snarky, but if the weather outdoors is uncomfortable enough to be using climate control, why would I want to open the window?

Because it smells bad inside? Because fresh air feels good? Not to be snarky, but how did you miss these use cases?

If it's pretty cold outside, then you're throwing all of the ostensible energy savings of a heat pump out the window the minute you open it to air out the house.

Following the thread of conversation, it just didn't compute to me:

>>>> Heat pumps are great for climate control >>> Yeah, ducts are dead >> What if you want to recirculate air in your house through your central air filter to eliminate smells? > Just open the window

It's like we've hit a contraction: the premise is that we care about energy but the contractions is then that we don't and we open the window while climate controlling the house. So to me it does seem to prove that in some climates, duct work with a central blower and filter mat not be dead.

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

#293

Post by PaulHoule »

yaysyu wrote: post #290
PaulHoule wrote: post #283

Earlier quoted context omitted.

It doesn't get that cold in most places in Australia does it? Heat pumps need to be scaled for the maximum heating or cooling load, whichever is greater. The optimal situation is that the heating and cooling loads are similar, but in colder parts of the U.S. the heating load is much larger than the cooling load and the case for the heat pump is not so good as a place where the need for heating and cooling are more ba…

Depends on your frame of reference but in Melbourne it can get to around 1 degree Celcius in winter (33~F). Sometimes subzero but very rarely

In upstate NY it gets a lot colder than that

https://en.wikipedia.org/wiki/Syracuse,_New_York#/media/File...

the average temperature is below freezing for four months.

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

#294

Post by mvnuweucxqokii »

kccqzy wrote: post #291
catiopatio wrote: post #261

Earlier quoted context omitted.

You do realize that “open the window and hear that air” is massively energy inefficient, right?

I don't know; is it more energy inefficient than having a fresh air intake via a duct? Maybe they are comparable in the absence of a heat recovery ventilation system (mentioned by a sibling comment upthread)?

You don't necessarily need to take in fresh air to freshen air in certain ways. It might suffice to pass it though a good filter.

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

#296

Post by thehappypm »

fifteenforty wrote: post #235
thehappypm wrote: post #228

Earlier quoted context omitted.

Daikon is way worse than Mitsubishi from what my hvac guy tells me

Mitsubishi Electric or Mitsubishi Heavy Industries? I sourced opinions far and wide and in the end it seemed to be a coin toss between Mitsubishi Electric and Daikin. A lot of it comes done to parts availability, and both seem very strong in Australia.

I live in a cold climate

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

#297

Post by kccqzy »

rubicon33 wrote: post #164
kccqzy wrote: post #132

Earlier quoted context omitted.

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.

Which CO2 detector do you have?

The one recommended by SwiftOnSecurity years ago. https://twitter.com/swiftonsecurity/status/12230876092216115...

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

#298

Post by teruakohatu »

thehappypm wrote: post #288
teruakohatu wrote: post #270

Earlier quoted context omitted.

In New Zealand I have seen small heatpumps in bedrooms, but I would have to say it is extremely rare. But we have many very toasty hallways leading to cold single glazed bedrooms!

That might be a climate difference — it gets below 0 Fahrenheit here every winter, as I understand it, NZ is quite a bit warmer, so maybe the strategy of “heat the core of the house and let it radiate out” works.

There are historical and cultural reasons for our poorly insulated and heated homes, but "heating the core" is not one of them.

In the last few years the central govt has brought in legislation requiring landlords to heat and insulate homes to a certain standard.

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

#300

Post by hinkley »

HellzStormer wrote: post #240
twawaaay wrote: post #231

I am in constant bewilderment about all of the talk of saving electricity but still so few homes having a very basic device like heat exchanger. At its very simplest it is just a box where incoming air is being heated by outgoing air without both getting mixed. It is a bunch of pipes, radiators and two fans in a box. Whether you heat or cool your house, an open window is energy loss. The heat exchanger lets you keep…

Logically (and ideally), the incoming air and outgoing air would exchange heat until they are at the same temp, which would be in the middle. So I would not expect an efficiency higher than 50% unless there is some special tech I'm not aware?

Counterflow heat exchangers move the air past each other so that the input air hits the exhaust air in reverse order. The last spot the intake air touches is the first place the exhaust gas touches.
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