the manifestos (ground loop and radient floor)

stevehull · 01-02-13, 08:29 AM

The holiday has been kind to me. Joined just very recently, and have spent much of it reading every pages of AC hacker's home brew heat pump manifesto and then the same for the radient floor discussions (also a manifesto in itself).

The global similarities are striking. In each case the loop design and construction is critical. Enthusiasm and the need to do something NOW have clouded the judgement of the well intentioned (as several have self admitted) and the bottom line is that homework must be done BEFORE the joys of looping plastic (in ground or under/in/on floor radient).

The issue of climate and degree day is also critical as well as the persistance of climate. Those who are very cold and stay cold can put in large thermal radient masses, but it MUST be isolated from loss by large R impediments. Those that have climates with significant swings (cold one day, warm the next) need to consider radient masses with small BTU volumes and ways to anticipate outdoor temp swings.

There is little discussion on matching the heat load (BTU/square area/degree day) to the input heat parameters. That is a big loss as that is where I start all my discussions with clients.

Sadly, there is no final or even periodic consensus (consenses?). The newcomer can jump in and read for several hours (not reading the entirety) and come up with a radient system that doesn't heat (too little conduction), heats the subslab volume (innappropriate ratio of R values under and above radient PEX pipes) or too large a heating system (or using boiler high temperature perspective) and have a system where the home overheats on a cold but sunny day.

Much can be said for ground loops where larger diameter exchange pipes, some circuits in parallel and deep earth holes need punching as well as matching fluid flows to the heat pump.

Then again, we have perspectives where people are paying dearly for BTU's (Europe) vs. those where a kWhr is 5-7 cents.

Finally, radient floors are not a magical cure for winter heating. A well designed, tight house may need only a very small radient floor system, but it must be put in for low cost as the return on investment is very high with a well designed home. This is where some judgement and knowledge is critically needed.

"That which is given away freely is little regarded". The posts/comments of many here are worth many thousands of $ (many tens of $ actually) in aggregate and I particularly value the experiences of those that have described the important utility of close spacing radient PEX loops (4 inches; 100 mm) when we use a low temperature circulation fluid. Same with providing adequate ventilation with heat recovery ventilators (HRVs) or energy recovery ventilators (ERVs). I have long fought (20 years) those battles with contractors . . . .

Over the years, I have come to many of the same conclusions as many of the posters, but we do dearly need some sort of place where global points need to be made, collected and posted. I am not sure how to do this as reading the manifestos is like reading a story of a long journey where different people drive a long way to another area. Some go through mountains, others through deserts, some go straight and others meander and each in different cars. Then each tells the story of the truth of their journey (and each story is true!). Like the blind men describing an elephant . . . .

This is quite entertaining, but I come away with hundreds of little anotations on which page this is noted and the weblink to that tool and such. Yet I also LOVE the spirit of the DIYer who pushes forward against the sage advice of the expensive (and often ill advised) experts in the USA HVAC industry who are so slow to adopt rational heating/cooling perspectives (as in Europe).

I also am a long term moderator of a forum (livestock health/management) so I do understand the difficulties of a periodic collection of wisdom and the endless need to repeat basic information to newbies in ways that they can understand. But do we do so in a way that costs them more in the long run as they don't see the big picture?

That said, the value of the posts here are staggering, yet the summaries are oddly absent - and I don't know a good way to do this. Does everyone have to read the entire manifestos to become fluent? I don't think so, but want to know what others feel would be a way of condensing some of the more relevant information into a more succinct form.

Ideas?

May 2013 bring you warm feet in winter, a cool breeze in summer and energy bills that make you smile . . .

Fornax · 01-02-13, 02:40 PM

Welcome Steve!

I did read your post with a smile on my face because you give this community (Ecorenovator) a lot of praise but also pinpoint some of the shortcomings of our forums, which I recognize.

I am one of the guys working on an DIY HRV-ventilationsystem, and when I am finished I must make a post where I summarize all the information about my build in one central place, so people do not need to read page 23-31 of a huge thread just to sift out the info I posted over the course of weeks. And others should do similar : -)

What I missed dearly in the beginning was a babelfish explaining many common terms and units of measurement and the relationship/calculation between them used here. (BTU, therms of gas, m^3 of gas, degrees F/C/K, M^3/hr <--> CFM, hectopascal <--> PSI and the such.)
Perhaps a table comparing energyprizes per country/state over the years would be entertaining (Piwoslaw, Kostas and me have comparable prizes but 3 very different climates, and especially the prizes are unfamiliar to people in the USA). My toes curled when I saw people using 4000KWh of electricity per month, but although it surprised me it is perfectly normal depending on where you live (price, climate, availability of certain resources).

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That said, the value of the posts here are staggering

I totaly agree. I did learn more and understand many things better by reading part of a thread, return later and let things sink in but it would add even more value to the boards if some kowledge would get more organized, perhaps a bit wiki-style.
For example in my HRV-project I made some decissions other people cannot make, and I can explain why I made mine for my specific situation and why other people should not do the same.

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May 2013 bring you warm feet in winter, a cool breeze in summer and energy bills that make you smile . . .

Over the past years my energyconsumption has been declining, alas the price of gas and electricity has not. And my feet are warm but my floor is not, an upcoming project: insulating my floor (which is a different floor than yours, with a different crawlspace, and different challenges : -)

So may 2013 bring us happiness, more comfort, a lower eco-footprint, lower bills, knowledge to share and fun DIY-projects.

Daox · 01-03-13, 09:17 AM

This is why I have traditionally suggested people make new threads for new topics. I run a few different forums and this technique seems to work quite well for me. I personally have found it easier to find information when it is broken down into managable sized threads. You can always add links to related subjects. If you're building a DIY whatever, you can link to the thread or even specific post where you and many others theorize and throw ideas around about how you want to go about doing that something.

For example, I started a new thread on sizing my solar hot water pump because there is a ton of info on how to size a pump, what pumps are out there, the different pump technologies out there, and more. I didn't want that stuff in the middle of my thread on installing a solar hot water panel thread. If someone wants to know about how to select a pump they simply read the thread on pump selection. My solar hot water thread has a link to the pump selection thread to point people to that info so it is not missed.

However, there are others on this forum who think that everything should be contained in one huge thread that contains everything you need to know on that subject. By reading that thread you have all the information you need to do that job or project.

There are pros and cons to each side here. I personally don't care (although I am admittedly biased) all that much as long as I and others can find what they're looking for. So, that also means I'm open to suggestions.

Fordguy64 · 01-03-13, 10:49 AM

I'm with daox.. I like the idea of a different thread for each thing.. Who wants to read 30 pages of info that they don't need to know just to find that one little thing they need.. Also I had wondered about setting up a wiki page of some sort on the different things that just has the info and not all the chit chat

Fornax · 01-03-13, 05:25 PM

I understand the reasoning behind isolating separate subjects/builds/projects into separate threads. But reading through the 25+ pages on the DIY-HRV took me several days, and it had a ton of links in it, which contributed to the thread taking days to read.
At that time the subject was new to me, and it was helpfull for me to study the subject over several days and let things sink in.
I didn't mind the fact that the thread spans over 3 years as people in it learned too and found new information elsewhere, bringing more interesting links to follow...

I guess many unregistered readers think the same, or about half of them.
Also I do agree that builders ought to create a separate thread with condensed info about their project (when almost finished) for various reasons. (Specific build condensed into 1 thread, more pages to be found for interested people around the globe via searchengines, etc.)

RobbMeeX · 02-23-13, 11:35 PM

As a Noob to all of this, There is days of info here, some good, some questions on posted info, some bad opinion. On Ecomodder, you set up a top 65+ list of proven thoughts. Now I know houses come in more models than cars, but an index of mod/reader voted threads might be helpful to at least get an initial summary of thought. Until then, I'll keep reading!

AC_Hacker · 02-26-13, 10:17 AM

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