Solar Space Heating with Bob Ramlow
Green Radio
Sean Daily

Episode 111 - Solar Space Heating with Bob Ramlow

Sean Daily, Green Living Idea's Editor-in-Chief, discusses solar space heating technologies and strategies with Bob Ramlow, Author and Owner of the Artha Sustainable Living Center.



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Sean Daily: Hey, everybody. Thanks for listening in today on’s “GreenTalk Radio.” This is your host, Sean Daily. Today, we're going to be talking about solar space heating, and to talk with me on that topic is Bob Ramlow who’s the founder of the Artha Sustainable Living Center. Bob has been a guest on this program before for solar water heating, which is another podcast you can find on the website. So if you take a look under that, you can go into solar water under Topics under Green Building or just put it into the Search.

So Bob, welcome back to the program.

Bob Ramlow: It's a pleasure to be here, Sean.

Sean Daily: It's always a pleasure to have you. Just for anybody who maybe isn't pretty or hasn’t listen to the previous podcast, can you give us just a quick overview of the Artha Sustainable Living Center, when you founded it, why you founded it, and a little bit of your background?

Bob Ramlow: We moved out to the country [xx] right after my college career in 1971 here in Central Wisconsin. I had received the degree in Natural Resources. When I was a senior in college, one of my university professors took me over to his house. He thought he had something for me that I might be interested in. You have to understand, of course, that studying natural resources, it was doom and gloom in a lot of ways. Every time you turn around, there was another ecological disaster that we were studying.

So this university professor took me over to his house and he happened to have, probably, one of the, if not the very first solar heating system in Wisconsin in his backyard. I saw that heating system that day and a light went on in my head. Here, we've been studying doom and gloom; bad, bad, bad, and all of a sudden, bingo! Here is an answer and seeing that collector that day really set me on my life’s path.

Sean Daily: OK, and how long after that did you found the Center?

Bob Ramlow: Shortly, within several months. Now, of course, the Artha has evolved over years. For many years, it was an organic farm where we did a little educating here and there, the little consulting work. But with the onset of the oil embargo in the 1970s, we became more involved in renewable energy at that time. It actually evolved further into having a retail store for many years selling wood stove solar heating systems and wind energy. We did the whole gamut.

Eventually, I sold the retail parts of the business and kept the solar consulting. Two years ago, we built a straw bale zero energy house that incorporates Pb as well as solar thermal for heating. At that point, we still had an old house, so we changed that into a bed and breakfast and now we house people when they come to our Center to take classes.

Sean Daily: OK. So there is this sort of this is [xx] as it were, of uses of solar that we see commonly in green building projects, and just in general, where we've got solar Pb, which you mentioned [xx] which is a solar electric energy to [xx] or completely remove, in some cases, the need for energy coming in from the power company. We've got solar water heating, which you and I discussed on the last podcast, and then we've got solar space or solar thermal heating. I want to start with this question, which is, is it possible to completely heat your home only using solar?

Bob Ramlow: No. The reason the answer is no is because in virtually every climate that requires space heating, there's just too many cloudy days in a row at certain times during the year when you're going to need heat. So you always have to have some sort of a backup heating source.

Sean Daily: OK. I did not know that, that’s interesting. So it's like the solar Pb, it's going to be obviously dependent on the amount of solar energy that you're receiving. So that really is something that’s going to lessen the load on the conventional system, but not necessarily replace it.

Bob Ramlow: Yes. With Pb, of course, you can have a grid-tied system and utilize the utility, in essence, as your battery. So during the sunny time of year, you could bank a lot of kilowatt hours in there and use them up and that’s essentially what I do with my Pb system. I way over produce during the summer, build up all these credit, and then use it up in the cloudier time of the year and end up with zero energy. With thermal, you cannot do that because it's essentially impossible to store heat for a very long period of time.

Now, there are two types of solar heating systems. Well, there's a lot of ways to look at it, but one way of looking at it would be a system that delivers heat when it's sunny. So that would be kind of similar to a passive solar house. When it's sunny, you have solar heat; when it's not sunny, you use your backup. The other type of solar heating system would be a system with storage. So in that case, on a sunny day, you collect heat, use it during the day but hopefully collect enough during the sunny time. So you're not only heating during the sunny time of the day but also during the evening and, possibly, into the next day as well.

Sean Daily: OK. So you can bankroll this to some degree then.

Bob Ramlow: Right.

Sean Daily: How exactly do you store the heat in this application?

Bob Ramlow: That brings up the next subject, but another way to look at solar heating systems would be to classify them as regular storage or seasonal storage. The traditional solar heating system that has been popular for a very long time would be the non-seasonal storage. With a system like that, typically, you use water for the heat storage so you have to have a water storage tank. It's essentially just like a regular solar water heater which, of course, have solar panels, a water storage tank, and probably, a pump and heat exchange and some other associated components.

A space heating system is just a big one of those. So during the day, the sun shines, you collect the heat in the collectors, transfer that heat to a storage tank, and then pull heat out that storage tank as needed. In most climates, you're going to be able to heat your house completely in the spring and in the fall. It's only in the dead of winter or whenever there's really extended cloudy periods that you'll have to use your backup.

Sean Daily: OK. We're going to take a moment right here to put in a commercial break and then we'll be right back with Bob Ramlow who’s the founder of the Artha Sustainable Living Center. We're talking today on the topic of the solar space heating. We'll be right back.

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Sean Daily: OK, and we are back with on our topic solar space heating with Bob Ramlow, founder of the Artha Sustainable Living Center at Bob, please continue. You were just talking about the process of integration into an existing heating system and some of the issues there.

Bob Ramlow: Yes. Before we get into integrating heat solar into an existing heating system, just to finish off the description of the different types, there is another type of solar heating system that has what's called “seasonal storage capability.” With that type of a heating system, you have--in the case of type of systems that are popular today is utilizing a lot of thermal mass. In this case, what you use primarily is sand and this would be the type of the system that could be used in new construction but it's very difficult to use in existing construction. So you essentially make an insulated sandbox underneath the main floor of the building or basement floor if you have a basement and you direct the solar heat down into that sandbed.

Now, the thing about the sandbed is that they're very big so you have possibly hundreds of tons of sand. Sand is very different than water, the seasonal systems are different than the water-based systems or the [xx] system, but you can start heating up your sandbed or your thermal mass in late summer and utilize some of that heat in the winter. So it takes months to heat the whole thermal mass up and it also takes months for it to cool down. So the advantage of the systems that have some seasonal storage capability to them is that you can get a larger percentage of your annual heat from the solar heating system. You're actually using the collectors for more months of the year.

Sean Daily: I see. Interesting.

Bob Ramlow: I just wrote an article that is in the November-December issue of “Solar Today” that really compares the two types of solar heating system, so that’s a good reference. As well as my book, “Solar Water Heating” that is available everywhere and certainly from the publisher, New Society Publishing.

Sean Daily: For those listening, we'll also have a link to that book for the listeners of this podcast on the site as well, so you can click directly on that link. Yes, I was remiss on this and assumed that you are an offsited author on this topic as well as others related to sustainable living. I'm curious about, if you don’t mind just switching here a little bit towards the cost side. One of the questions I know that people have, they're sold on, “This sounds really good. This might be for me.” One thing was about integration, I jumped again a little bit on that because that was on my mind. [laughs] I was thinking about integration, I was just like, “OK, how do plug this into my existing system?”

Bob Ramlow: We can talk about that.

Sean Daily: Yes. OK, I'd love to hear a little bit about that.

Bob Ramlow: Well, if we talk about that first and then we'll get into the cost.

Sean Daily: Yes. Let's talk about that first which really dovetails into cost as well.

Bob Ramlow: Sure. The integrating of system, solar heat into an existing heating system, really depends on what type of existing heating system you have. The most efficient type of heating system available today that’s using fossil fuel, of course, would be some sort of a radiant heating system
Sean Daily: In the floor.

Bob Ramlow: Radiant floors, radiant ceilings, things like that. Now, the characteristics of that type of a system is that it operates at a fairly low temperature. That is very good when you're thinking about integrating solar into it because, well, solar is a low grade heat source as compared to a fossil fuel or a flame, that’s high grade heat. Solar is much more gentle and it's a low grade heat. When we walk outside, we don’t fly immediately.

Sean Daily: Right, luckily.

Bob Ramlow: So integrating into any kind of a radiant heating system is very easy and it's just a matter of installing a couple of valves and a little bit of electronics. The way that would work is if there's solar heat stored in the storage vessel and there's a need for a heat in the building, then it uses the solar to deliver heat into the building. If there's a call for heat and there's no solar, then the backup will do it, so it's very easy.

Now, another popular type of a heating system is a forced air heating system where there's some sort of a furnace and ductwork. It could even be a central air-conditioning system that has ductwork as well as and a blower and that’s fairly easy to integrate solar into that. Essentially, what you do is you put a radiator in your ductwork and whenever you need heat, you would pull it off of the solar if there's any there and turn on the blower at the same time.

One difference with integrating into a forced air heating system is that, again, because most furnaces using lots of fuel, they get very hot. A tongue-in-cheek name for a force air heating system is a scorched air heating system because the air gets very warm. So when you put your hands by the register, the air feels warm. When you're using solar, it's not going to feel as warm because we don’t have as much intense heat. So what happens is the blower would tend to run for much longer periods of time.

Sean Daily: So it's more of an even heating, as you put it, lower grade, I guess, not in terms of efficiency but just in terms of the intensity of the heat that’s being produced.

Bob Ramlow: Correct.

Sean Daily: So it needs to be sort of over a longer period of time, it's more even and gentle rather than this sort of blasting hot air concept.

Bob Ramlow: Right, exactly. One of the negative things that makes forced air heating system uncomfortable is the furnace comes on, it gets a little too warm in the room. Then it cools off and it gets a little too cool and then it gets a little too warm and it's bouncing around with solar. It is, like you mentioned, very more even feel.

Now the other type of heating system that’s popular would be a traditional hydronic heating system that’s using radiators or baseboards. Solar does not integrate very well into that type of a system and the reason is that type of a system is designed to have, under most instances, an operating temperature, the fluid going through the piping, of a 180. That’s quite hot and that is on the very top end of what you would see a solar storage tank’s temperature stay at.

So usually, if a home has a traditional radiant heating system in it, we don’t integrate the solar into that. Instead, we'll put another heat delivery method into the building like radiant floors or some fan convectors, which is a radiator with a fan on it. You can deliver a lot of heat with a very small package, very small unit. So you have a couple of those inside the house, which is we don’t tie in with the baseboard radiators.

Sean Daily: I think, anybody who grew up in a house with standard radiators are checking about the standing kind over near the wall, running water through them that gets so hot. If you have the misfortune of putting your hand or any other exposed body part near that, you get a nice burn, that type of thing.

Bob Ramlow: Yes.

Sean Daily: Yes, yes. So it's not practical for that. OK, well, we're going to take a quick break here for a commercial and then we will be back to our conversation with Bob Ramlow from the Artha Sustainable Living Center.

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Sean Daily: OK, and we are back with Bob Ramlow. So I'm just curious about on the cost side, let's talk about the cost-effectiveness and the question that comes up a lot for people is about ROI. Can you talk to that?

Bob Ramlow: Yes. As we mentioned, when we were talking on the last podcast about the solar water heaters is with the solar water heaters at today’s fossil fuel prices, it’s actually cheaper to heat water with solar than it is in any other way. Now, one reason that is so cost-effective is because we use hot water 12 months of the year every single day. So that means that our solar equipment is going to be working at maximum efficiency all year round. With the space heating system, of course, during the summer--certainly dependent on where you live--you won't need much if any solar heat during the summer months. So during those months, the equipment is essentially idle, so the return of investment for a solar space heating system isn't quite as good as it is with the plain solar water heater. Nonetheless, it's still an excellent investment.

I don’t like to talk about the cost. There is no question that when you buy a solar heating system, you have to make an investment in the equipment. But oftentimes, people get sticker shock because this is not necessarily inexpensive equipment. It is copper, glass, aluminum, all items that are related to fossil fuel. So when fossil fuel prices go up, so does the cost of the raw materials to make these collectors. Like take copper, copper is a semi-precious metal and so if there is an investment, but that’s not the right way to look at this type of an investment.

For instance, when we buy a home or buy an automobile, we are making a long term investment. So we need to look at the solar space heating system or solar water heating, for that matter, in the same way. If you finance your solar heating system, let's say, you put it on your mortgage and you’ve got a 15-30 year mortgage. In the case like that, your monthly payments, at today’s fuel prices, will be very similar to your energy savings, so your cash flow impact is little or none.

Sean Daily: Yes, and that’s true. I haven’t gone through it myself, that is definitely true in that situation. So you raised a good point, which is it's important to think of it in those types of ways and there are many different ways to slice this. I mean, you can go and you can do if you happen to be doing a refi, of course, there's closing cost involved and so forth. Certainly, this is a good thing to have in mind if you're looking to do a remodel anyway and you're already going to be doing a refi as part of that or you're doing a refi anyway, maybe that becomes the catalyst because of rates or what have you.

Bob Ramlow: Right.

Sean Daily: But, you know, it is a realistic question and I appreciate your viewpoint on it. I think of it, there's a variety of different people out there. There's light green, medium green, dark green, and not that that’s necessarily a scale of righteousness or anything.

Bob Ramlow: Well, and we didn’t even talk about that issue, the greenness or the morality of doing solar. Of course, it's very moral and it's very green. For many years, when fuel was cheap, there was the environmentalist that kept me in business. Now, of course, it's everybody because not only do we argue the greenness or the environmental aspects of renewable energy but these things stand on their own strictly economic terms as well.

Sean Daily: Yes, and that’s good. Some people, I like to think of being inclusive and we want to include everyone even if they initially had a primarily an economic driver behind making a decision. These things can become infectious where you make a decision even if it's not purely for green reasons as it were. But that can then beget other decisions that you might make in your life with regards to your car or your transportation or whatever, the way that you manage your waste [xx]. You know, the plethora of things that affect our lives and the sustainability of the planet. Actually, the planet is not having the problem, it's the species that’s having the problem. Plants are going to be fine, we're the one's that are in question.

Bob Ramlow: Right. Here's another economic way of looking at things and that is life cycle costings. Now, this is something that businesses do all the time but residential people don’t do it very often. What life cycle costing is is where you look at the upfront cost of the investment and then you also look at the operating cost of that investment over a certain period of time. So if we look at, for instance, the heating system--and I'm just going to use whole numbers out of the air here--let's say a heating system cost $5,000 to put in. But to operate that heating system over 10 years might be $50,000 total bill. Now with solar, you might have a $20,000 upfront cost with no operating cost over those 10 years. So with lifecycle costings, the regular furnace cost us $60,000 and the solar cost us $20,000. So lifecycle costing is another economic analysis that people use overtime to weigh investments.

Sean Daily: That is a concept I had not yet heard of so I appreciate you bringing that up. What I'm also fascinated here is the connections between the different types of systems and how they interrelate. So for example, generating the [xx] energy and then reusing that in other systems that also have benefit in homes. Whether it's an electric car or you're using that energy source which is a greener energy source in other systems such as these, it's very interesting how you can sort of start funneling all these things together and creating a sort of a synergistic effect--to use an overused term--in the process.

Bob Ramlow: Right, and that brings up a point, too, is usually when you have a solar space heating system, a home heater or business, you also have a solar water heater, it's just part of it. So they're usually not separate, they're usually together. The heat is coming in and some of it goes to the domestic water heat and the rest of it goes to space heating.

Sean Daily: Bob, that is all the time we have for today, so we're going to have to sign off. I want to thank you again for being on the program. Bob Ramlow has been my guest from the Artha Sustainable Living Center. Bob is also the author--in addition being the founder of the Center--of “Solar Water Heating: A Comprehensive Guide to Solar Water and Solar Space Heating Systems” from Mother Earth News Wiser Living Series. Bob, thanks again for being with us.

Bob Ramlow: My pleasure, thank you.

Sean Daily: Thanks as always to everyone listening in today. Remember, for more free, on demand podcast, articles, videos, and other information related to living a greener lifestyle, visit our website at We’d also love to hear your comments, feedback, and questions. Send us an email at [email protected].

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