Isn't radiant much more efficient for heating than forced air, regardless of local climate?

Efficiency is improved or lost at a number of different places, including but not limited to radiator type, construction type, floor coverings, system design and even energy source. There are always a number of things that are popular, but that doesn't mean they are more efficient or even the best bang for your buck. In my area, "EnergyStar" homes masquerade as the "green" choice. Lots of marketing, lots of hype and better than what some builders are turning out, but certainly not the last word in building science or efficiency.

Here are a few thoughts;

1. Me, too.
2. Have you considered passive solar design principles? You can probably save 20% or more right there.
3. Off grid means stick more closely to electric. Maybe break your electric system into two panels so you can easily separate necessary loads from luxury loads.
4. Sealing up your envelope and controlling air infiltration will probably do more for that problem than choice of heating system.
6. I have propane, and only for cooking. It was a tremendous PITA to put in for just that, but a tankful will probably last 15 years.
7. Very difficult to run any heating systems on a solar/battery system. Heaviest draws are usually at night which means batteries are limiting factors. Obviously, systems in which the majority of the heat is provided by chemical means like oil, gas or wood are easier on electric draws, but if it has to be heat pumps, you want small inverter-controlled heat pumps. PG&E offers grid-tied programs, meaning you can feed excess power into the grid, get credit for it and use it at night. You can add a battery system at a later time, if you still want it.
8. West windows are by far the most difficult to control in terms of unwanted heat gain for your house.

ETA: Northern California is classic solar country.  If you were doing something with solar thermal panels and some sort of heat storage, it would make the radiant a more obvious choice, particularly with your off-grid leanings.

Posted By NRT.Rob on 22 Apr 2013 09:39 AM
I find it interesting that anyone can, in one breath, note that companies that design on a regular basis can do shoddy work (which is absolutely true) and then turn around and suggest DIY design. DIY Design is typically the CAUSE of the nightmare scenarios out there. I find the cognitive dissonance between strongly recommending PEs and then recommending DIY design kind of amazing.

Educating yourself is really great, and getting siggy's book is great so you can sniff out who you want to partner with and make sure they know their stuff. But I've seen most of the nightmare scenarios you can see, and while radiant isn't quite rocket science, you can still learn something new about it every day, 15 years in. It seems unlikely to me that anyone is going to DIY a great heat pump radiant system on their first time at bat.

That's why I want a professional design, and perhaps that designer might caution me on common installations mistakes that he might feel would happen on his design.

I've been involved in construction for 30 years and feel I have a reasonable handle on what I can't and can do.  I'm not sure I would install my own roof trusses (don't have the equipment or the man power, but I'm not afraid to do all the electrical and plumbing in my own home, most of the interior carpentry, lay my own tile and floors, etc... I've run and crimped a lot of pex in my days.  I think, with a lot of education and perhaps a smidgen of guidance, I can install my own radiant system, or at least 90% of it.  My Spidey sense tells me I may not be competent enough to "Design" my own system, or at least not without hundreds of hours (in addition to schooling myself on the actual installation) of research.

I'm willing to consider professional design, so that I don't have the train wreck you have witnessed.  If you don't feel that most can install their own systems, that is duly noted.  I have more confidence in myself than that, and I think I'm smart enough to know when I'm out of my element. Installing the system does not intimidate me, although I'm not arrogant enough to think I don't need to do a lot of homework.  Designing the system is another matter.

This is a point well taken. When most people say solar, I think Passive House. More practical in most cold climates.

I don't have a problem with DIY install of non-combustion and non-refrigeration equipment, provided you understand what you're putting in and the design is sound and documented to a sufficient level for your understanding. We work with DIY'ers all the time. I do have a problem with DIY design as most DIY'ers fail at the load calculation, long before they get to the actual heating system design. No software can save people from bad input, bad decisions when partitioning up a floorplan, etc. and there is no feedback to say you did it wrong until long after it's too late to easily fix many things. So overdesign is the answer there. and at that point, you can generally find pro help cost effective in backing off on overly expensive or exotic materials.

Once in awhile it's done properly. but I have two guys who have worked on load calcs under me for 5+ years who do this every day... hell, I program my own load calculation software and I STILL have to sit down and make judgement calls for complex or non standard situations and how they should be handled. short of a true modelling program, which none of us are using, how you handle your approximations matter. I've said before there are times it's not a big deal, such as if you have a very simple building with obvious lifestyle zoning requirements. but for most people, a more nuanced view can yield great results.

if you are doing ANYTHING off grid here, or want to go net-zero, you absolutely will require pro help. Most pros can't even do that sucessfully and that's a classic case where extremely aggressive pump management and such would yield great results.

I do have a problem with DIY design as most DIY'ers fail at the load calculation

Rob, from the reports we see here, that wouldn't be limited to DIY'ers.

absolutely agreed on that front, good point. especially at on the "greener" end of building science.

Posted By NRT.Rob on 22 Apr 2013 09:39 AM
I find it interesting that anyone can, in one breath, note that companies that design on a regular basis can do shoddy work (which is absolutely true) and then turn around and suggest DIY design. DIY Design is typically the CAUSE of the nightmare scenarios out there. I find the cognitive dissonance between strongly recommending PEs and then recommending DIY design kind of amazing.

Educating yourself is really great, and getting siggy's book is great so you can sniff out who you want to partner with and make sure they know their stuff. But I've seen most of the nightmare scenarios you can see, and while radiant isn't quite rocket science, you can still learn something new about it every day, 15 years in. It seems unlikely to me that anyone is going to DIY a great heat pump radiant system on their first time at bat.

Our experience has been that most of the nightmare scenarios out there are created by out-of-state companies that provide less than competent free design service when one purchases their over-priced products and encourage customers to handle the installation themselves.  When there is a problem, the company then blames the DIY installation (or even the in-state pro installation) and washes themselves of any liability leaving the customer to fend for themselves.  We hear this story all the time from people who have experienced this situation and use the free software on our website to understand and resolve their problems.

 

Yes, we always recommend using a licensed/experienced professional engineer to perform the analysis/design and using a licensed/experienced HVAC contractor to install the system.  Ideally the design/install team are from the same state that the project will be accomplished and they have a good working relationship…even better if they are one-and-the-same.  This goes a long way to mitigating the nightmare scenarios and providing the customer better resolution options if there are any problems.  However, there are many states that do not have any HVAC contractor licensing requirements at all:

www.NationalContractors.com/hvac.htm 

 

So sometimes a person has to choose between working with an unknown, unlicensed entity versus taking on the project themselves.  Someone willing to spend the time and having the mental capacity to understand Sieg’s book can successfully accomplish the design and installation themselves.  Again, having a foundational understanding of the design will better enable this person to accomplish the installation and resolve any setup or operational issues.  We have received success stories from many people all over the states/world who have used the free software on our website to accomplish the design and installation themselves.  They often tell us that they saved anywhere from 50 to 70% of what they would have spent hiring this out even if they made a few mistakes that they had to correct themselves. 

 

We have found that someone who is involved and motivated with their residential project and who is also willing to learn and capable of performing, can do a great design/installation themselves.  Nevertheless, I would certainly agree that not everyone is capable of doing their own design/installation…and a person certainly needs to know their limitations before making this decision.  Anyhow, this is my rationalization regarding your perception of my cognitive dissonance between strongly recommending PEs and then recommending DIY design.

"Anyhow, this is my rationalization regarding my cognitive dissonance between strongly recommending PEs and then recommending DIY design." We can certainly all agree on that! eheheheheee

Here in Minnesota we call it fishing...

Posted By BadgerBoilerMN on 22 Apr 2013 01:05 PM
"Anyhow, this is my rationalization regarding my cognitive dissonance between strongly recommending PEs and then recommending DIY design." We can certainly all agree on that! eheheheheee

Here in Minnesota we call it fishing...

Yes, I would agree Minnesota has great fishing...but apparently no state HVAC license requirements.

Which is why I have to design ALL of the HVAC systems in the state (with some help from a few PE for the commercial projects) :-).

Posted By BadgerBoilerMN on 22 Apr 2013 01:11 PM
Which is why I have to design ALL of the HVAC systems in the state (with some help from a few PE for the commercial projects) :-).

I don’t see any problem with that.  I just don't like out-of-state companies leaving customers in a bad situation and giving hydronic floor heating an unjustly bad reputation.

ICF is right…passive solar likely makes more sense than just hydronic floor heating for this location, and integrating the two systems is something you should consider too. Below-Floor hydronic for new construction doesn’t make any sense to me.

sailaway, I appreciate your exposition. I am very familiar with the kinds of scenarios you are talking about. there are plenty of shysters out there and in our industry there are even a few that are very high profile that I have a very dim view of for their shoddy practice and recommendations. In some cases it borders on what I think should be consider criminal.

that said, I have seen a lot of people who can understand the equations in siggy's book just fine get themselves into trouble. the devil is in the details. it's not that a person is not CAPABLE. it's that they are not EXPERIENCED and there are a lot of things to take into account in a custom design situation. In a simple situation, not such a big deal. If you are trying to do something with significant limitations like heat pump driven radiant... red flag city.

Fair enough Rob. I guess I missed where the OP indicated he was locked into doing a heat pump hydronic radiant floor heating system. That would certainly be a challenging DIY design and installation, and I now fully share your concern about the OP NOT doing the design (and the installation) themselves.

Heat pumps certainly have their advantages, but this approach wouldn’t be our first recommendation for a remote, off-grid location where a heating system failure often needs to be accomplished by the home owner in a timely manner. I would be considering some combination of passive solar heating, masonry heater (wood fueled), and perhaps hydronic radiant floor heating using a boiler (perhaps solar collector and LP fueled, and integrated with the passive solar heating system). If you will have LP for the kitchen range, it often makes sense to use it as your backup fuel for your backup heating system.

Well, everyone starts out as inexperienced with everything they do in their life and in their profession too. So my point was more around how best to assess and trade hydronic radiant floor heating design/installation risk and cost. Again, some people can overcome a lack of experience by taking the time and applying themselves to the task. Some of the greatest accomplishments of mankind were accomplished by inexperienced people at the time. So this decision is really more about time, cost, and risk…and the person’s honest, self-assessment of their capability to accomplish the task.

just to be clear, I don't have a problem with DIY install. as long as it's properly designed and documented. I have many, many clients who show how well that can work.

none of the systems you just described are really great DIY first jobs.

and everyone does start off inexperienced, but one would hope that inexperienced people would not lead the charge in an area they are not experienced in. no amount of time on forums and with books will get most people to a place where they are designing a really good system though. Some, but very, very few. Many, if not most of my clients are engineers of other professions, computer programmers, and other very technical people. For years, most of them found me only after extensive internet research. they still make great errors in their system design because they simply don't know what they don't know and don't have the experience to select amongst competing claims. Not to be too snarky about it, but even really well educated and obviously intelligent engineers that are non-specialists in this realm can make really bad decisions, like sizing pumps in a closed hydronic system with consideration for the total height of the system, for example. I can cost justify most of my design fee if all I do is reduce pump sizing from something like that to something more reasonable on first and operating costs, in most markets across the country.

I have clients submitting full designs to me from professional design suites. but the tools don't make the design, and 90% of them, even from extremely intelligent and motivated people, are not very good in some critical details. Which details? well, good question. the only way to be sure you get them all is.... good design practice.

I recognize my bias in this but I have just seen so many examples to justify my opinion that I can't apologize too much for it.

to both Sailaway and Rob.

Being off grid is not a high priority. It would be nice but not realistic for my budget.

Maybe a heat pump hydronic system is not a good choice for a professionally designed but DIY installed system. Remember it does not get that cold here, but it also doesn't get that warm either, so passive solar might not be good to rely on. Marine layer fog can keep sunlight from being as successful on passive solar as it might in other areas.

Assuming off grid is out of the equation, why would a heat pump boiler not be a good idea? It seems to be working on the one house in the area I toured a few weeks ago (it was a Daikin Altherma). I know the owner is big into green systems and energy efficient homes (not saying he knows what he's doing though). He did 2 years of research for many elements of this home. I am not sure if the builder picked the heat pump equipment or the HO. And perhaps this will end up being a disaster for that HO. I don't know. This home was also using a hydro electric generator in a creek on his property, charging a closet full of batteries, but he was also hooked up to PG&E.

Is the success of passive solar bound by the same temperature and sunlight conditions as a heat pump, which extracts whatever heat is in the air? I would think you need some level of sunlight present to pass heat through the glass inside the house. But a heat pump can extract whatever available heat is present, no?

And I guess I could relent the actual boiler and heat pump installation to a local mechanical contractor. But what would be wrong with installing the pex, warmboards (or whatever gets designed in) and manifolds myself on a properly designed system?

Yah, what Rob said. I am feeling really warm and fuzzy right now, in a totally experienced, analytical way way of course.

We recently performed a hands-on boiler/radiant floor rescue for a mechanical PE who specializes is refrigerated containers. Naturally, a dumb plumber such I, couldn't teach him anything about heat transfer, but the scale and application is not familiar even to the commercial mechanical engineer. Then there is the hydronics thingy.

I love my job! PS Most of our out-of-town clients source their own products with our advice and install most radiation, but it is wise to have a professional do the start-up and perform annual service just to secure the warranty and keep it all safe.

we are using the altherma at our shop and love it. it is not a DIY project, because it is refrigeration equipment, just a boiler is not DIY, because it's combustion, and those things are either dangerous, evironmental risks, and/or require specialized tools to do well which you do not own... but the non-altherma parts of the system certainly can be DIY.

I say it's not a DIY design situation though because it can't spit out unlimited water temps and making sure it has the output you need is not as straightforward as doing a fast heat load and looking at a label rating.

it does not get that cold here, but it also doesn't get that warm either, so passive solar might not be good to rely on

Passive Solar is nearly always used as supplemental. It is not intended to be the sole heating source, particularly because almost anywhere can have stretches of cold, overcast days.

So, in response to your later question about passive solar, the answer is "No", it isn't really bound by anything. The whole idea is that you admit the radiation and try to capture it when it is available and restrict it when you can't use it. There are a number of things that nearly any home can do to be more passive-solar friendly. Most of them are done during design rather than as retrofits.

I am 600 mi North of you and my passive solar appears to be performing very well. I'm about 500 meters from the salt, so we see long stretches with the overcast and local fog, too. We are estimating about 28% - 32% of the heating needs are covered by the passive features. This is heated by an Altherma.

You are squarely in heat pump territory, too.

Posted By JohnRLee on 22 Apr 2013 04:39 PM
to both Sailaway and Rob.

Being off grid is not a high priority. It would be nice but not realistic for my budget.

Maybe a heat pump hydronic system is not a good choice for a professionally designed but DIY installed system. Remember it does not get that cold here, but it also doesn't get that warm either, so passive solar might not be good to rely on. Marine layer fog can keep sunlight from being as successful on passive solar as it might in other areas.

Assuming off grid is out of the equation, why would a heat pump boiler not be a good idea? It seems to be working on the one house in the area I toured a few weeks ago (it was a Daikin Altherma). I know the owner is big into green systems and energy efficient homes (not saying he knows what he's doing though). He did 2 years of research for many elements of this home. I am not sure if the builder picked the heat pump equipment or the HO. And perhaps this will end up being a disaster for that HO. I don't know. This home was also using a hydro electric generator in a creek on his property, charging a closet full of batteries, but he was also hooked up to PG&E.

Is the success of passive solar bound by the same temperature and sunlight conditions as a heat pump, which extracts whatever heat is in the air? I would think you need some level of sunlight present to pass heat through the glass inside the house. But a heat pump can extract whatever available heat is present, no?

And I guess I could relent the actual boiler and heat pump installation to a local mechanical contractor. But what would be wrong with installing the pex, warmboards (or whatever gets designed in) and manifolds myself on a properly designed system?

There is nothing inherently wrong with using a heat pump if the complexity/servicing is acceptable to you.  There is nothing wrong in you doing whatever you want on this project.  The cost and the risk are totally yours to address/mitigate.

 

I do think that you should first sort out what your ultimate long-term goals are for this building.  Do you ultimately want a net zero or a net positive building…and eventually being off grid?  If so, there are things you can provision for and then add later.  For example, you could put the pex in floor and not actually hook it up until later.  You could put in the footings/foundation to allow a future masonry heater to be built.  You could orient your building to take best advantage of passive solar heating with just a standard home window suite but allowing for future solar fenestration expansion.  You could use a service panel that facilitates adding future active solar, hydroelectric, or generator power.

 

Passive solar can be successful most everywhere.  How successful largely depends on how aggressive you get with your solar fenestration and your climate.  You really need to delve into these subjects to learn more about them and then just run some numbers for your building to gain a better sense of what is possible for your location and for your long-term vision for this building. 

Again, we have detailed instructions/info and free software on our website for heat loss analysis, hydronic radiant floor heating design, passive solar design, masonry heaters, and hydroelectric.  Once you have a better understanding about what you think you want, then engage and hire the best people you can find to get their opinion and recommendations.  At this point, you should be able differentiate between BS and facts.  My only advice beyond what I have already previously mentioned would be to apply due diligence and carefully check credentials and references of anyone you hire, especially if they are out-of-state.