Mikael Korhonen

Yes, this works fine as long as your pump's head rating covers the lift to the top of the coil. Once the loop is primed, water will happily run downhill through the coil back into the tank — the pump only needs to overcome the height difference, not the friction of the whole loop.

Air locks are the real nuisance here. Put a small manual bleed valve or just a tee with a cap at the highest point of the coil so trapped air can escape when you first fill it. Keep the coil pitched so it never dips and rises again mid-run — air collects in those dips. After the first prime, a closed loop with no leaks rarely re-traps air.

Good question! Our all-in delivered cost usually lands around 8-12 cents per kWh, with grid transfer fees and taxes added on top of the spot price. The real win is the cheap overnight hours, where the spot price often drops to near zero and we run the water heater and other heavy loads almost for free.

John, you don't need shop-grade gear for a real-world test on LiFePO4. The cheap way: fully charge the battery, then run it down through your inverter with a steady resistive load like a space heater, and track the watt-hours with a shunt-based monitor or even a plug-in meter on the AC side. Note the total Wh when the BMS hits low-voltage cutoff, convert back to Ah at nominal voltage, and compare with the label. The flat discharge curve just means voltage alone won't tell you much — the Wh counter does the real work, which is exactly why the bluetooth BMS estimate plus a periodic full run-down is the practical routine for most folks.

Sorry to hear that, Dan — a wrench across the posts can dump an enormous amount of current in a fraction of a second, and as Douglas said the battery itself may have taken damage even if the case looks fine. I'd charge it up, then put a real load on it (headlights on for ten minutes) and watch whether the voltage holds; if it drops fast, the internal plates are probably warped and the battery is unreliable. If it does hold, clean the melted post down to bright metal, seat the clamp tight, and keep an eye on heat at that terminal for the first few cycles.

A well-tuned RMH really is remarkably clean at the point of use: the insulated burn tunnel hits temperatures where combustion is nearly complete, so once it's up to temperature the exhaust is mostly CO2 and water vapor with very little smoke or PM2.5, far below a conventional wood stove. The nuance is that electric heat has zero point-of-use emissions at all, so the claim really holds when you factor in the grid mix behind that electricity or compare per unit of delivered heat against fossil sources. In practice, the biggest particulate win of an RMH is replacing a smoky conventional stove or open fireplace, where the difference is dramatic and immediately visible.

On a 6-inch system I would keep the exhaust path through the bench and oven as straight as possible, since every extra turn and pinch point eats into your draft and can stall a cold start. With the chimney near the barrel end, make sure the bypass rejoins the exhaust path downstream of the return bench rather than right at the manifold, or the bypass will short-circuit heat away from the mass. For the oven, putting it close to the barrel and manifold where the gases are hottest will give you more usable cooking temperature than placing it at the far end of the bench run.

One thing I'd add to the comparison idea: ambient temperature is the biggest variable, since manufacturer specs are usually measured around 25°C and a fridge sitting in a hot outbuilding will use far more. A cheap inline DC watt-hour meter between the battery and the fridge over several days gives you the real Wh/day number, which beats any spec sheet when sizing the battery and panels.

Welcome to the forums, Tina! The builders list Samantha linked is the best starting point — a few of the folks on it travel regionally, so it's worth contacting the ones in neighboring states too. You might also ask in the Tennessee homesteading and permaculture groups; that's often how people find an experienced builder nearby. A small batch-box heater with a short bench is a great first build if you ever do decide to try it yourself down the road.

A cheap and very automatable sink is a resistive water-heating element wired through the inverter or charge controller's auxiliary output, so excess PV gets dumped into the hot water tank only once the batteries reach float. Even without fancy controls, a simple timer on the water heater, freezer, or dishwasher set to run during the usual surplus window does most of the work. Around here that window is roughly 11:00-15:00, so anything heat-based that can run on a schedule lands perfectly.

Michael's numbers show exactly why pre-cooling changes the battery math so much — the heavy work happens while the panels are producing, so the battery only has to cover the overnight simmer. One trick from my own off-grid setup: a freezer makes a perfect opportunity load on a charge controller's diversion output, soaking up surplus solar that would otherwise go to waste once the batteries are full. Same principle applies to pre-cooling a cabin — the coldest thermostat setpoint should coincide with peak sun, not with bedtime.