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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

#201

Post by thomasjb »

LatteLazy wrote: post #42

Everyone is looking for an easy answer to climate change / energy costs / energy independence etc. But there isn't one. Fusion remains decades away, Fission is very expensive and unpopular, Most renewables are intermittent etc. Heat pumps are one more tech with very limited potential (range of temperatures, efficiency over that range, power output limits, need for a heat source, size, cost etc).

What's your perspective on sustainable biomass usage such as pollarding and coppicing, and bringing energy usage inline with that which can be fueled by them, in addition to small scale wind?

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

#202

Post by nomel »

lll-o-lll wrote: post #192
phyzome wrote: post #144

> owners of drafty homes may need to take on the added cost of insulation when installing a heat pump Installing good insulation is also really important even if you're not using heat pumps! With bad insulation, you're wasting energy no matter what technology you're using.

If you live in a warm climate, I personally think insulation is the worst (excepting roofing). Not because of efficiency, but because you isolate yourself from nature! The traditional Queenslander (look up Bluey if you don’t know what I mean), has so much going for it. It allows airflow through the whole house, a protected outside to sit and be with nature, lizards coming and going, bliss! This hermetically sealed en…

Insulation can be orthogonal to fresh air. Ventilation energy recovery units [1] exist to help reduce loss from fresh air (and are code for new houses where I am). This has the benefit that you can have more fresh air, for the same heat loss, since the loss will be from the fresh air, rather than through high thermal conductivity through the non-breathable portions of the walls.

1. https://en.wikipedia.org/wiki/Energy_recovery_ventilation

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

#203

Post by darknavi »

lll-o-lll wrote: post #192
phyzome wrote: post #144

> owners of drafty homes may need to take on the added cost of insulation when installing a heat pump Installing good insulation is also really important even if you're not using heat pumps! With bad insulation, you're wasting energy no matter what technology you're using.

If you live in a warm climate, I personally think insulation is the worst (excepting roofing). Not because of efficiency, but because you isolate yourself from nature! The traditional Queenslander (look up Bluey if you don’t know what I mean), has so much going for it. It allows airflow through the whole house, a protected outside to sit and be with nature, lizards coming and going, bliss! This hermetically sealed en…

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.

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

#204

Post by kccqzy »

mvnuweucxqokii wrote: post #163
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.

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 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.

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

#205

Post by WillPostForFood »

fifteenforty wrote: post #167
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).

A recirculating central heating system doesn't do that. As mentioned below you either need exhaust only ventilation, balanced ventilation or ideally ERV/HRV. All of the above are available in both ducted and ductless forms.

>Ducts are still needed to circulate air

>A recirculating central heating system doesn't do that.

They definitely circulate air, and they definitely filter the air. Whether there is fresh air depends, mostly no.

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

#206

Post by 0_____0 »

metadat wrote: post #198
fifteenforty wrote: post #161

Earlier quoted context omitted.

I paid real money to have my ducts removed. They cause issues installing comprehensive insulation and caused hot/cold spots on the ceiling.

Honest question: Why would one care about cold or hot spots on the ceiling? I don't spend much time up there.

It’s still a thermal path between inside and outside, and thus wastes energy if you’re trying to maintain an internal temperature that is different from the external temperature. Also there are radiative effects - hot spots on ceiling will radiate IR into your space. Just try standing under a corrugated steel roof in the summer.

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

#207

Post by [deleted] »

WillPostForFood wrote: post #205
fifteenforty wrote: post #167

Earlier quoted context omitted.

A recirculating central heating system doesn't do that. As mentioned below you either need exhaust only ventilation, balanced ventilation or ideally ERV/HRV. All of the above are available in both ducted and ductless forms.

>Ducts are still needed to circulate air >A recirculating central heating system doesn't do that. They definitely circulate air, and they definitely filter the air. Whether there is fresh air depends, mostly no.

[deleted]

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

#208

Post by nemo44x »

poutine wrote: post #184
nemo44x wrote: post #171

Earlier quoted context omitted.

Why not install heated floors? That would be my choice in a new build.

It's expensive and it doesn't cool. Also doesn't circulate the air. I have some fancy filters and humidifiers as part of the system I'm putting in.

It will certainly cost more, especially since you can’t share the venting and blower. But I’d get it quoted to compare. Electric systems have really come down in price per SqFt. Now your climate doesn’t get month after month of freezing temperatures so maybe it won’t be as dramatic but the energy cost savings can be huge. Plus the overall experience of it is the best imo.

You could still circulate air with the blower running in fan mode and you may not need humidifiers as that’s the biggest negative to forced air heat imo.

Curious which humidifier systems you’re looking at?

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

#209

Post by TheSpiceIsLife »

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…

This is exactly the same setup I have here in Launceston.

Another great thing about having three seperate units is if one breaks, rare as it is, you're not stuck without heating / cooling.

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

#210

Post by [deleted] »

teruakohatu wrote: post #114
fifteenforty wrote: post #112

Earlier quoted context omitted.

You have to think carefully about where you run the ducts. They can be a huge source of energy loss. 40% is the number quoted by the EPA. Most roofs in Australia still aren’t sealed. The air barrier and insulation barrier is the ceiling. The roof space itself is not insulated, so the ducts are exposed to extreme temperatures, thus destroying the efficiency. Here is just one article on it: https://newenergythinking.co…

I hadn't considered that. My argument with split systems, at least how they are installed in NZ, is that they are usually installed in the main living area and if there is a second unit, in a corridor. So corridors are heated or cooled far hotter or colder than they need to be in order to heat/cool bedrooms.

[deleted]
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