TheBackShed.com

Forum Index : Windmills : VAWT powered heat pump (no electricity)

Author

Message

nweeks

Newbie

Joined: 22/01/2007
Location: Australia
Posts: 36

Posted: 12:52am 29 May 2013

Copy link to clipboard

Print this post

Hi all,

It's been a few years since I've been here, but I've had a thought rattling around in my head for a few days now.

Did a quick search, and can't find anyone who's done it, so here goes.

In a nutshell, it's replacing the outdoor unit of a reverse cycle airconditioner/heatpump with a completely passive design, with no electric stage adding inefficiencies. (Wind->Electric->Compressor becomes Wind->Compressor)

(Additionally, I've moved to South Hobart, and it's damn freezing here)

Obtain an automotive AC Compressor, mount it on a tower with a VAWT (Lenz2 or similar, whatever's in fashion)

Refrigerant pipes up the tower are heavily insulated. The high pressure one from the compressor is with foam.
The low pressure one (from the house) has two paths. They might be in series, or switchable depending on air temperature:
- One path through a traditional 'Outside air to refrigerant' heat exchanger like normal AC units (for night time use)
- The other path encased in an evacuated(vacuum filled) glass/pyrex/flouro lamp tube, and the copper pipe is painted black. This simple solar collector therefore pre-heats the refrigerant before it reaches the compressor)

When the wind blows, the VAWT spins the compressor, performing the duty of the outdoor unit of your traditional Reverse Cycle AirCon unit, but without the electricity required to run the compressor and fan to pull the outside air through the heat exchanger.

And on those cold, blustery nights, the air heat exchanger hopefully will heat the refrigerant like a normal Reverse-cycle AC unit does.
On sunny but windy days, the evacuated tube heats the refrigerant, and allows the heat to be stored inside.

The only powered component is the fan on the inside unit (apart from control electronics). If a convection radiator(before the restrictor) was used inside the house, this also could be passive.

Nigel Weeks
nweeks at karbonit dot com

Madness

Guru

Joined: 08/10/2011
Location: Australia
Posts: 2498

Posted: 01:54am 29 May 2013

Copy link to clipboard

Print this post

Not trying to put a damper on your idea but wouldn't it be simpler just to use a wind generator to make electricity and run the AC off of the power produced?

Designing a house with good insulation, thermal mass and passive solar heating would reduce the heating requirements greatly. I remember one episode of Grand Designs where the house set into the side of a hill with only one side facing the sun. This side was totally double glazed glass, the owner had sensors through out the house and recorded all the data over a year and the house remained warm with no heating apart from the body heat of the occupants and the sun. This was in the UK which is probably not too much unlike your climate in Tasmania.

Of course if you are trying to heat an existing house it is a different matter.

An idea I should explore further is using a pump to extract heat energy from the air/water/ground. Then use this heat to boil a refrigerant liquid/gas to drive a turbine connected to a generator which would power the heat pump and should have excess energy. This is not perpetual motion of over unity nonsense. Heat pumps produce more heat than you can get from using a heating element from a given power input. The extra heat comes from the air in the case of domestic heat pump type hot water systems. So what I am talking about is a way to harness this heat energy that is all around us.

I am sure I am not the first to come up with this idea and perhaps there is a good reason why it won't work. If can be done though it would mean free energy/heat available just about anywhere.

There are only 10 types of people in the world: those who understand binary, and those who don't.

nweeks

Newbie

Joined: 22/01/2007
Location: Australia
Posts: 36

Posted: 02:27am 29 May 2013

Copy link to clipboard

Print this post

Yeah, but where's the fun in that? :)

The wind gen would have to be up at speed to be producing the 240vac, and the 6kw or so to do the job, whereas the direct-attached compressor will start sending the warmth inside as soon as there's enough wind to spin it (of course, minus losses, and temperature losses due to non-moving refrigerant in high pressure line) :)

Yeah, having a hoover that could suck energy from any source and store it - now that would be fun! Oh for a few dollars and a year of nothing to do but tinker... :)

Yes, I'll be building a passiv haus one day, but while we're renting here, there's little I'm allowed to do.

(Haven't asked the landlord about a 10m tower either, but I'm sure if I ask nicely... :))

Nigel Weeks
nweeks at karbonit dot com

Madness

Guru

Joined: 08/10/2011
Location: Australia
Posts: 2498

Posted: 03:03am 29 May 2013

Copy link to clipboard

Print this post

While you are renting you may need to settle for putting on a few extra layers of clothing.

There are only 10 types of people in the world: those who understand binary, and those who don't.

Downwind

Guru

Joined: 09/09/2009
Location: Australia
Posts: 2333

Posted: 05:42am 29 May 2013

Copy link to clipboard

Print this post

Just kick your aircon in on your car at idle and see how it drags the revs down, they are horsepower hungry to drive the compressor.

With todays restrictions on refrigerant gasses i doubt you would even be allowed to construct such a project, unless you used something like bang gas (propane) but there is a good reason why its known as bang gas in aircons.

Pete.

Sometimes it just works

Print this page

To reply to this topic, you need to log in.