Design and Build Spiv's Solar and Geothermal House - Page 3

jeff5may · 07-05-16, 11:20 PM

Read this:
What is a Desuperheater or Hot Water Generator?

Whether to run thermal or pv solar collectors or arrays (or both) is a big decision that you want to make early, as it will steer your system design plans. Both types of systems have advantages and liabilities. In the last decade, prices have come down on pv panels, and modular, scaleable, reliable controls are readily available. There are quite a few members with working systems operating as we speak. Those with electric vehicles are especially pleased with the choices they made, and most plan on further upgrades in one way or another. It's one of those things that helps you down the path to netzero or uber-efficiency in your energy budget. Once they have something running and laying waste to the utility bills, most people feel an urge to increase their savings.

Once again, I'm just tossing around ideas. Im not a salesman trying to steer you towards a certain product. Just shining some light on these modern building trendsetters.

jeff5may · 07-07-16, 10:47 PM

If you are looking at installing a solar thermal collector array, take a good hard look at "steam back" system design. They combine the strengths of other types of systems, and are safe and durable over the long term. The steamback can be over built, containing more collection area than other types of systems. This gives you more productive operation when the sun is out, covering demands overall throughout the years. On especially sunny days with low demand, the panels simply stagnate and the liquid boils out if it can. No harm, no foul, no problems. Slick and simple operation.

Spiv · 07-08-16, 03:21 AM

Quote:

Originally Posted by jeff5may

If you are looking at installing a solar thermal collector array, take a good hard look at "steam back" system design.

We don't seem to have any problems with the systems available in Oz, in previous houses, we often went on holidays and left the house empty in the middle of OUR summer and the solar panels didn't boil or were otherwise affected by excessive heat.

mejunkhound · 07-09-16, 03:48 PM

......help me out with those figures and tell me where to find info on DIY GSPH

If you have not already done so, read ALL 1,910 discussion in AC_Hacker's 'heat pump manifesto' thread !

99% of your technical questions will be answered there.

For the solar questions, look at those threads.
You really should look at solar first given you high energy rates in Perth area.
To assess your solar potential, research 'solar insolation' NOT installation or insulation, inSOLation - e.g.
Australian Climate Averages - Solar exposure

mejunkhound · 07-09-16, 04:07 PM

Just for curiosity I looked at the link on the prev post.

You are pretty much under clouds in July there, eh? Only about 3 kW-hr per day available for a 2 by 3 meter array of solar cells, $1 at your rates, right when you need heat!

so maybe solar is not a good deal in Perth due to overcast skies when you need the power for gshp ?

In January, you will get about $5 worth of power a day from a 2x3 meter array.

Yearly average solar power of maybe close to $1000 though.
A 2x3 meter array PEAK power rating would be about 1.2 kW, Maybe $1500 DIY installed - pretty good payback due to high rates there!

Kinda like parts of Germany, where power rates are close to 40 cent kw-hr, and nearly everybody has some solar or wind.

Does AU have solar subsidies or tax credits? Look into it !

jeff5may · 07-09-16, 10:09 PM

COP: coefficient of performance. A measurement of heat moved divided by power consumed. Watts / watts. Higher is better. Most manufacturers use weighed (seasonally adjusted) measurements for performance figures. All refrigeration units are more effective and efficient when the outdoor air or ground water is close to the target indoor temperature. As the difference widens, it takes more energy to move the same amount of heat. The weighted figures make it easier for the common buyer to choose between units.

Spiv · 07-19-16, 06:24 PM

So,

from the advice received and what I learned from it, it seems that the most appropriate course of action is:

Insulate as much as economically viable.
Ensure good airtightness of the house
Use mini splits
Use Solar PV to assist minisplits in summer
Use gas to to assist minisplits in winter.

Did I get it right?

Minisplits are definitely the easier and cheaper option up front.
I had them installed in previous houses and it only takes an afternoon to get them retrofit, in a new install it might even be easier as the electrical and plumbing can be worked out in advance.

What I have against them in the noise they make and the seem to waste a lot of energy (a lot of heat is produced by the external unit).

I was sort of sold to the idea of hydronic floor heating as a sort of quite and ecological way to get warm in winter, but I might have to give up that idea.....

AC_Hacker · 07-20-16, 09:52 AM

Quote:

Originally Posted by Spiv

[*]Insulate as much as economically viable.

The more you are able to slow heat loss, through rigorous control of infiltration (will require a very high efficiency HRV), and heat loss through walls (insulate > 2X the required insulation in you area)...

...And also use construction that will prevent thermal bridging (which will eat away 18% of your insulation value), the less you will need to heat and cool your house.

Just imagine, silent comfort with no moving parts, due to proper design of your structure.

-AC

07-19-16, 06:24 PM	#7
Spiv Lurking Renovator Join Date: Apr 2015 Location: On a Catamaran sailing the Oceans Posts: 23 Thanks: 8 Thanked 0 Times in 0 Posts	So, from the advice received and what I learned from it, it seems that the most appropriate course of action is: Insulate as much as economically viable. Ensure good airtightness of the house Use mini splits Use Solar PV to assist minisplits in summer Use gas to to assist minisplits in winter. Did I get it right? Minisplits are definitely the easier and cheaper option up front. I had them installed in previous houses and it only takes an afternoon to get them retrofit, in a new install it might even be easier as the electrical and plumbing can be worked out in advance. What I have against them in the noise they make and the seem to waste a lot of energy (a lot of heat is produced by the external unit). I was sort of sold to the idea of hydronic floor heating as a sort of quite and ecological way to get warm in winter, but I might have to give up that idea..... __________________ Keep smiling Stefano To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

07-05-16, 11:20 PM	#1
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Read this: What is a Desuperheater or Hot Water Generator? Whether to run thermal or pv solar collectors or arrays (or both) is a big decision that you want to make early, as it will steer your system design plans. Both types of systems have advantages and liabilities. In the last decade, prices have come down on pv panels, and modular, scaleable, reliable controls are readily available. There are quite a few members with working systems operating as we speak. Those with electric vehicles are especially pleased with the choices they made, and most plan on further upgrades in one way or another. It's one of those things that helps you down the path to netzero or uber-efficiency in your energy budget. Once they have something running and laying waste to the utility bills, most people feel an urge to increase their savings. Once again, I'm just tossing around ideas. Im not a salesman trying to steer you towards a certain product. Just shining some light on these modern building trendsetters.

07-07-16, 10:47 PM	#2
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	If you are looking at installing a solar thermal collector array, take a good hard look at "steam back" system design. They combine the strengths of other types of systems, and are safe and durable over the long term. The steamback can be over built, containing more collection area than other types of systems. This gives you more productive operation when the sun is out, covering demands overall throughout the years. On especially sunny days with low demand, the panels simply stagnate and the liquid boils out if it can. No harm, no foul, no problems. Slick and simple operation.

07-09-16, 03:48 PM	#4
mejunkhound Apprentice EcoRenovator Join Date: Apr 2011 Location: PNW Posts: 197 Thanks: 0 Thanked 47 Times in 31 Posts	......help me out with those figures and tell me where to find info on DIY GSPH If you have not already done so, read ALL 1,910 discussion in AC_Hacker's 'heat pump manifesto' thread ! 99% of your technical questions will be answered there. For the solar questions, look at those threads. You really should look at solar first given you high energy rates in Perth area. To assess your solar potential, research 'solar insolation' NOT installation or insulation, inSOLation - e.g. Australian Climate Averages - Solar exposure

07-09-16, 04:07 PM	#5
mejunkhound Apprentice EcoRenovator Join Date: Apr 2011 Location: PNW Posts: 197 Thanks: 0 Thanked 47 Times in 31 Posts	Just for curiosity I looked at the link on the prev post. You are pretty much under clouds in July there, eh? Only about 3 kW-hr per day available for a 2 by 3 meter array of solar cells, $1 at your rates, right when you need heat! so maybe solar is not a good deal in Perth due to overcast skies when you need the power for gshp ? In January, you will get about $5 worth of power a day from a 2x3 meter array. Yearly average solar power of maybe close to $1000 though. A 2x3 meter array PEAK power rating would be about 1.2 kW, Maybe $1500 DIY installed - pretty good payback due to high rates there! Kinda like parts of Germany, where power rates are close to 40 cent kw-hr, and nearly everybody has some solar or wind. Does AU have solar subsidies or tax credits? Look into it !

07-09-16, 10:09 PM	#6
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	COP: coefficient of performance. A measurement of heat moved divided by power consumed. Watts / watts. Higher is better. Most manufacturers use weighed (seasonally adjusted) measurements for performance figures. All refrigeration units are more effective and efficient when the outdoor air or ground water is close to the target indoor temperature. As the difference widens, it takes more energy to move the same amount of heat. The weighted figures make it easier for the common buyer to choose between units.