The Micro-controlled Green Home (warning: A bit "preachy")

[futz]

I also believe there are methods for "purging" the hot water from the pipe and returning it to the master tank so the heat is not lost between hot water uses. But, it's a rather nasty, complex system that might be more trouble than it's worth (involves an extra tank and electric pumps).

Hot water recirc is actually very simple. No extra tank needed. Just some circ lines that go typically one to each area with plumbing, a simple manifold with balancing valves and a relatively cheap circulator (pump) with timer and aquastat. Whenever the timer says it can run, and the aquastat says it's cold, the pump pulls water from the far ends of the system and pushes it back in the cold side of the water tank, forcing hot water out into the hot mains. That way it's close to the faucets and ready for quick use. This setup can't be easily retrofit in most houses without a major renovation though.

There are systems like Grundfos' UP15-10 Comfort System that allow you to retrofit hot water recirc to an existing home. Quite a smart design. Uses the cold line as a return, so no need for new return lines. There are other brands too, but Grundfos is top quality stuff.

Anyway, we're getting pretty darn off-topic here...

 

[crashsite]

Hmmmmmmm....what I'm not "getting" here is a sense of, "Wow! Sounds like a great business opportunity and a way to apply my electronic, PIC and computer programming skills to help save the planet (and make a pile of money for myself at the same time)".

But, I guess that's understandable in a messaging service like this where the thrust seems to be the theory and how-to rather than as a networking place to exploit the technology. Perhaps further posts and threads will continue to expand on the possibilities for implementing and integrating the various devices and methods to green up homes.

 

[Hero999]

I simply put in a 75 watt globe and now my fridge only uses the RE bank @ 75 watts to keep our fridge/freezer dead cold ( infact it's just turned on or the fridge becomes a freezer).

That sounds like a waste of energy to me.

An electrical fridge probably draws an average of 75W considering the compressor isn't run continiously.

Regarding the electrical instant heating idea.
The current consumption wouldn't be an issue on a UK 3 phase style power supply - A 50A three phase breaker can supply up to 34.5kW.

However, using electricity for heating is expensive and inefficient. The power source normally comes from fossil fuels powering heat engines that are only 40% efficient at the most.

I've always thought about solar power. I know that photovoltaic cells work better at higher intensities but are they better at lower temperatures? If so they could be water cooled and the waste heat could be used to heat water.

Solar powered air conditioning also interests me, would it be cheaper to use photovoltaics to run a compressor or to directly use the heat to power an absorbtion powered refrigeration system?

Wind power is also good idea. Normally the alternator is connected to a bridge rectifier which is connected to an inverter and the excess power is fed back to the grid.

This all sounds good but I do like the idea of charging batteries so you don't need to be connected to the grid most of the time. You could also use the battery voltage directly for most applications (like lighting) which would save the extra energy lost in the inverter. You could also use the load dump resistor as a water heater.

 

[Nigel Goodwin]

This all sounds good but I do like the idea of charging batteries so you don't need to be connected to the grid most of the time. You could also use the battery voltage directly for most applications (like lighting) which would save the extra energy lost in the inverter. You could also use the load dump resistor as a water heater.

Sounds like you ought to have a visit to C.A.T. in Wales and see how it works in practice - but essentially you need a super-insulated house to start with really.

 

[crashsite]

Solar powered air conditioning also interests me, would it be cheaper to use photovoltaics to run a compressor or to directly use the heat to power an absorbtion powered refrigeration system?

I agree with your thinking. We're unbelievably spoiled and when it stops being easy (like using wood, coal and oil/and byproducts for energy), we tend to throw up our hands in frustration and whine about how it can't be done (except for Bryan1...per an earlier post...but, hell...if you live on kangaroo meat you can expected to be a he-man). The fact is, the sun and moon, as well as the earth itself, are giving us more energy every second of every day than we can possibly use. We just need to be better at harvesting it.

I did post a thread that addressed the solar air conditioner and got some very good and thoughtful responses:

https://www.electro-tech-online.com/threads/solar-concentrator.35131/

 

[Hero999]

The idea of using electricity for air conditioning is quite silly when there's plenty of solar power to do the job and normally when there's no sun it's not required anyway.

Another thing is could you directly use wind power to turn the compressor on a standard vapour phase cooling system? This might be useful in countries that are both hot and windy like Australia.

 

[crashsite]

Another thing is could you directly use wind power to turn the compressor on a standard vapour phase cooling system? This might be useful in countries that are both hot and windy like Australia.

That's an interesting thought and, the first thing that sprung to mind was the Altamont Pass. It's one of the first and major wind farm projects and is is located in a natural wind tunnel there in northern California. It's in cattle and farming country and fairly easy trucking distance of Sacramento, the San Francisco Bay area, Fresno and environs (Probably 10 to 15 million within about 200 miles radius with fairly easy rail access to the Los Angeles, Reno and Las Vegas areas)).

This is a Google Earth .kmz file so I hope it works here (if you have the, "Panoramio" layer turned on, there's also a couple of associated photos:

https://www.madras.net/sala/misc/Altamont Wind Farm.kmz

They could directly compress coolant with some of the turbines and use the pylons as part of the heat exchanger since it's in the direct airflow. If they dug into the hills where the wind turbines sit, they could make huge, almost natural meat and frozen storage lockers, lined with the evaporator tubing. There's certainly plenty of electric power nearby to run any fans and lights needed.

 

[adaminc]

Water-heater manufacturers should start using Aerogel as an insulating material. It will be more expensive, but it would cut energy costs by a huge amount.

I remember reading about some tests done with Aerogel in winter coats made for an Antarctic excursion, they were acutally unzipping the coats in -40C weather because they were sweating. IIRC, it was Aerogel in a crushed form, large chunks though, not a powder.