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Passive solar design before you build On a new build, your very first stop is passive solar design. Strutting forward and designing a bad old stickhouse, and then bolting on solar as an afterthought, is wasteful. Passive solar design means engineering the building so it does not need active heating (except on rare occasion. The occasion is rare enough ...


17

Assuming that you are (a) on the regular electric utility grid and (b) are on the regular natural gas delivery system (i.e., don't require propane deliveries), as a general rule, natural gas heating will be most cost-effective in most parts of the US. If you are not on the regular (utility) natural gas system then electricity has some advantages. ...


12

If you design the solar thermal correctly, then given the annual solar insolation ( higher than my location in EU by about a factor of 2) then with good insulation you can avoid heating at all. But you will need to maximize the passive solar gain - allowing the sun's energy to enter the building in winter for example. Use underfloor heating driven from the ...


6

I have about 50 55-gallon drums stacked in my basement, all filled with water. They are stacked one on top of the other (bottom row/top row) along our north basement wall. I have two in floor-mounted fans, one pushing, one pulling, mounted in the ground-floor joist cavity (from above they just look like floor mounted cold air returns). During the day, the ...


5

Start with efficiency Harper's overall point about starting with an efficient envelope is dead-on; managing solar gains is going to be a huge part of it down in Texas, and you'll also need to be careful with how you apply insulation and air barriers to avoid trapping water vapor or moisture in wall or roof assemblies. The ultimate test of this is a blower ...


5

A common design in my area is a heat exchange tank upstream of a traditional gas or electric water heater. They use ethylene glycol (antifreeze) that circulates by thermosiphon action from a solar panel to the tank. The illustration below shows a more complicated (with pump and controller) version. So, you heat a tank of water with a coil full of antifreeze ...


2

You certainly don't want to install the solar panels before redoing the roof. Outside of that obvious point, I don't think it matters much. In Theory, having the panel supports installed as part of the process of redoing the roofing could make things simpler and better sealed, but in practice there are very few, if any, teams trained to coordinate these ...


2

This article provides excellent information about maximizing thermal mass: Phase Change Materials (PCMs): There is growing interest in the use of PCMs as a lightweight thermal mass substitute in construction. All materials require a large energy input to change state (i.e. from a solid to a liquid or a liquid to a gas). This energy does not change ...


2

One boringly unexciting approach is double drywall (and don't choose the lightweight type) though that is more often done when building or rebuilding/remodeling than as a retrofit without some other rebuilding/remodeling going on. It easily and unobtrusively adds a significant mass to the interior structure. Bang for the buck, and in most cases pound for ...


2

Any dark colored mass would become a passive solar heater for when the sun goes away and the room begins to cool. The mass could be as simple as concrete blocks, tiles or as costly as eutectic tube solutions. Years ago,I was interested in solar systems (I was years ahead in my imagination and thinking), and these were common ideas that were studied and ...


2

If you have enough solar in place to manage cooling during the summer, you probably have enough solar to manage heating during the winter. The question is if you can get more money from selling the solar to the grid, and using that money to buy gas for heating. The answer is usually yes, as long as you can sell to the grid at a decent price. Probably better ...


2

Yes, of course. There are a huge number of well-tested DIY projects you can find here: http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm I would heavily recommend browsing that site and learning from the experience of others who have already done what you're interested in doing so you don't burn even more money.


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In some mythical world where nothing else mattered, pumping your working fluid at maximum speed does limit the temperature rise of the collector surface, which limits the re-radiation of heat from the collector (re-radiated heat is not collected, thus, lost.) The simplistic theory is that raising 11 pounds or kilos of air or water 0.1 degree is more heat ...


1

You mentioned a solar pool heater in the first paragraph then switched to a solar collector for air in the second paragraph. Are you looking at "eutectic solar collectors" or sensible heat collectors? The beat efficiency is usually obtained when you extract the heat that is being put into the collector at the same rate that it is being collected. ...


1

I doubt sealer from the outside will be any sort of long-term fix. Either the joint has come apart or one of the pieces has split. Either way you'll need to take it apart, replace any broken parts and reassemble the parts with proper solvent.


1

A thermostatic mixing valve is the same device as a thermostatic shower, the mechanism is the same but the body & fittings different. So, have you tried adjusting the existing valve? Is there any chance it has got some debris in it causing it to fluctuate. Is the cold supply to the mixing valve restricted? It may be a faulty valve which needs ...


1

My preferred way is small split ac, reversible, COP of 1 to 3. Service can be expensive.


1

A window tint film would be a great option. Make sure you pick one that goes to the trouble of publishing their solar energy rejection performance -- any which don't might reasonably be assumed not to perform very well. You could choose an architectural film (ie designed for buildings) or an automotive film. One brand I can heartily recommend is Solar Gard. ...


1

Thermal draperies may be the best option. They can be opened when needed. The fabric is available to make your own at JoAnne Fabric, but ready mades are inexpensive and readily available.


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I would think about redesigning the roof to make the panel supports integral to the roof. Or you might keep a close eye on Elon Musk's work around solar roofs, where the panel IS the roof. Or go the opposite direction and get enough wind under the panels that the panels place your house effectively in shade, easing your cooling bills. Bonus points if ...


1

I don't think a plain resistor is what you want, I think a resistive load is what you want. Incandescent bulbs as mentioned would work and they're easy to find and work with. Of course you won't want an inverter in this setup, and 12V bulbs are readily available for automotive applications. But it isn't necessary to reinvent the heater, there are tons ...


1

The short answer is that electricity is not a particularly cost-effective way of generating heat, and solar panels are not a particularly cost-effective way of generating electricity, so this is not really a smart financial decision. If you are trying to generate heat from the sun you are much better off getting solar thermal panels. A PV panel only gets ...


1

Works (while the sun is shining), but is a very expensive option and not overly efficient. Solar PV panels of a remotely affordable price are about 10% efficient in terms of converting sunlight to electricity. Most of the rest of the sun's energy that hits them is converted to heat. So, from a sun conversion point of view, direct solar thermal collection ...


1

Gosh - a buck a therm is "expensive gas rates" - if I could get it (I can't and never expect to) it's more like a buck and a half...year round. So, you're using 1 million to 1.3 million BTUs/day - if you could manage storage swing of 50 degrees F (not unreasonable with radiant floor, a low-temperature emitter) that might be 3250 gallons of water (at a round ...


1

It would almost undoubtedly be a better use of your available money, time, and space to add insulation, not a complicated solar heat storage system, which after all, will do nothing for you half the year. Start with your basement and insulate the walls and the rim joists. Then move to your attic and air seal the floor and add about 12-16 inches of cellulose ...


1

Are the PEX hoses black and is the sun side of the re-purposed aluminum plates black? If not you may want to consider changing this so as to increase the efficiency solar energy absorption.


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Check with others who have installed solar water heaters in your climate zone. In mine (Massachusetts) friends who have them have not been happy with them; they don't produce much heat during the times of year when it is most needed. Experience with solar electric and net metering has been much more positive. (Anecdotal, small number of data points, don't ...


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