Ian's Thermal System

[IamIan]

Originally Posted by jeff5may

burning liquified petroleum gas

Doesn't matter , because LPG is not part of this system.

Originally Posted by jeff5may

Megajoules per kilogram is the metric

Feel free to use any units you personally prefer .. calories , kwh , joules , BTUs , ERGs , etc .. etc .. any of them can easily be converted to any other.

I don't exclusively use wh .. but it is the main unit of energy I use most often.

Originally Posted by jeff5may

Liion batteries come in around 0.8 on the same scale.

0.8 Mj is about ~222wh
LiFePO4 and Toshiba SCiB LTO I have are closer to around ~120wh/kg.

Originally Posted by jeff5may

you cannot break even.

Better than break even is regularly achieved with any modern heat pump operating over a COP of 1.

A heat pump operating at a COP of 3 provides 3 energy units of heat/cooling for every 1 energy unit of electricity input you give it .. what ever unit of energy you like .. wh , joule , ERG , calorie , etc.

Originally Posted by jeff5may

The going rate is 25 equivalent watts per square meter. This is with 10% pv panels.

No.

Standard 1 Sun condition is 1000 input light watts per square meter .. a 10% conversion efficient PV panel would output 100watts per square meter .. not the 25w you claimed.

The ~10% you sited has not been the 'going rate' for PV for about ~20 years now .. Maybe back in the days of Windows Me O.S. , but a few things have changed/improved in technology in the last ~20 years .. ~18% is the 'going rate' today .. low end systems are ~15% .. average systems ~18% .. high end systems up ~22% .. and top of the line systems up near ~39%.

The PV panels I got operate at 20.5% conversion efficiency .. soo, anybody using 20~30 year old ~10% PV doesn't matter to me .. in the 1 square meter area of your example under standard 1 sun conditions these ~20.5% conversion efficiency panels would result in ~205watts.

Originally Posted by jeff5may

In effect, you're replacing a continuous duty burner of a certain size with a PV energy concentrating storage system capable of less service at higher expense. YOLO, it's just money...

Correction
To spend less money .. to get a more capable system .. that pollutes less .. and enjoy many entertaining hours of a tinkering project along the way.

Originally Posted by jeff5may

The best way to use your dehumidifier scale phase change contraption is to integrate it into your window HRV.

Correction.
The pump I am using is a larger scale heat pump than a household dehumidifier is.

Originally Posted by jeff5may

Put each heat exchanger at the downwind end and reflect the heat outdoors or indoors, depending on the season. 300 CFM per ton of refrigeration, or 10 watts per CFM of heat transfer, is the standard target indoors. This setup beats the above solar concentrating system described above by a factor of COP times ten. All day and all night

No.

Although what you propose would work .. it would not be COP times ten .. aka a COP of 30 .. no , that is impossible from the arrangement you suggest.

Oh that's right .. we also have 'ton' as a unit of energy .. aka "freezing or melting of 1 short ton of pure ice at 0 °C in 24 hours" because humans just love using lots of different energy unit terms.

Your proposed system will be worse under some conditions.

Lower COP
Heat pumps get lower COP / efficiency the larger the difference in temperature between the hot side and cold side .. doing as you suggest would result in the system trying and get the most wh of heat to living space when it is the coldest outside temperature .. thus your design would result in a lower net average COP of the heat pump.

300CFM is allot of air flow .. for a ~800sqft with ~10ft tall rooms .. that's an entire house air change 55x every 24hr day .. Far to fast , and too often for me .. a little fresh air is one thing , but I think that is going a bit overboard.

In my design the winter night time heat pump doesn't have to work as hard as your design would .. my thermal storage will not be 10F temperature to try and pull heat out of .. thus I will get a higher/better average COP.

Originally Posted by jeff5may

All day and all night, without batteries. Off grid? No problem. Just run it off the power inverter.

Inverters need a energy source .. at night , something like batteries .. in order to function.

Originally Posted by jeff5may

A combined system is only as strong as its weakest component.

Sometimes .. not always.

Some combined systems are more robust than a single non-combined system would have been .. there can be a redundancy in the system design .. or the additional combinations can improve net performance (not be entirely dependent on it to function at all).

For example in my system design .. If 1 of the 2 heat pumps fail .. the system will still work (just not as well) .. even if both heat pumps fail .. the system will still work (just not as well) .. even if grid fails .. my system will still work (just not for as long as with grid) .. even if PV fails entirely .. my system will still work (just more from grid than if they do work) .. even if the solar thermal collector fails .. you guessed it .. my system will still work (just not as well) .. etc ... etc.

[IamIan]

Arranging the 55Gallon Drums.

I am a bit torn between two approaches .. But usually leaning toward Option2.

Option #1> Space Condensed.
Think/image one big block , with everything all together. Or in principle if it were just one large storage tank.

Pros:
#1> Less total gallons of room space consumed for the same gallons of storage space.

#2> Reduces the cost of components .. less material for plumbing when there are all close to each other .. less insulation and frame materials.

#3> Because it would also have less surface area, that means it will also retain it's internal temperature better.

#4> A little easier to 'sell' the idea of it being an 'appliance' .. If that option is needed/desired.

Cons:
#1> More difficult to accesses the 'buried' interior pieces should any service/maintenance ever be needed.

#2> Space is less available for 'multi-use'.
If I go 2 vertical drums high or 3 horizontal high , either way , that's floor the ceiling, no other use for that space.

#3> Not as easily modular .. should one ever want to expand or reduce the size of the system.

- - - - - - - - -

Option #2> Distributed / Modular / Multi-Use approach.

Kind of like John's design .. Although his website is down , I'll attach a pic I previous saved of the concept.

Pros:
#1> More easily modular .. expand or reduce system size as desired.

#2> Service & Maintenance access .. each drum unit is more accessible should any service or maintenance be needed.

This also allows for more easily bypassed bad modules .. should there ever be some type of service or repair issue with one of the modules , a bypass around that one faulty module is more easy to do .. not only helps with repair or servicing the issue module itself .. but also helps reduce the down time of the whole system while that issue is being serviced.

#3> More Multi-Use Space .. Although the gallons/cubic feet / etc of volume of the system is still occupied .. the top of the drums (especially vertical 1drum tall) is still usable as a counter / bench space above it.

Cons:
#1> More surface area , means more heat loss for the same insulation and same dT.

#2> More materials for more surface area , means more total system cost.

#3> More total volume from the room will be consumed for the same volume of thermal storage.

[jeff5may]

I'm repeating common, industry standard, optimistic figures for your benefit. For example, the 25 watts per sqft figure is a well researched average daily value. The sun doesn't shine at 100% when it's up, and it's down every night. I'm not trying to argue whether your specific panels peak out at some heavenly output or not on a cool, cloudless day. I'm just saying that the 25 is what the pros use for sizing utility-scale arrays. If you beat that, hooray, you're doing better than PG&E.

You're singing to the wrong choir regarding engineering and materials science. There are many masters lurking in this place, anxious to see something unique. This stuff has all been done before. It's your journey, amigo. I've personally been flamed and scathed in here for overstating or misrepresentating expectations of contraptions, both real and imaginary.

A heat pump isn't a free energy machine. All they do is pump gas in a circle. It's throughput is actually pretty lossy. Why do you think that efficiency numbers have constantly been improving over the years? Improvements in all aspects of design. A fancy compressor used to be a twin single; now it's a hyper heat turbo inverter. Micro channel heat exchangers and shtuff.

Speaking of heat pumps, here's my heat pump of the week. Currently on week 2 because I ran out of acetylene. The fresh air knob will become the heat/cool knob. Defrost will be handled by a freebie CNT 05008 board and a couple of 10k ntc thermistors.

[jeff5may]

So much in one post to respond to, what next? The HRV.

You need to be using a dehumidifier or refrigerator compressor for the HRV for a single family home or smaller dwelling. The figure is for a 10 to 13 SEER rig. If you plan on going higher efficiency, the CFM per ton (or CFM per horsepower if you're a reefer professional) will actually be higher. The main objective is to let the HRV heat exchanger do all that it can, then finish the air streams off with the heat pump. Tips include:

-MAKE A GOOD DRAIN if it's ever humid where you live.
-If you're repurposing dehumidifiers, only use condenser coils if you reverse direction. Evaporator coils like to pop.
-Craigslist and FB market are a perpetual source (mucho freebie)
- most every dehumidifier has a right sized, two or more speed fan. Plus automatic defrost.

[IamIan]

Originally Posted by jeff5may

I'm just saying that the 25 is what the pros use for sizing utility-scale arrays.

I remain skeptical that they do so.

Originally Posted by jeff5may

The sun doesn't shine at 100% when it's up, and it's down every night.

That is a different topic.

Similar to .. the time a ICE is not running is a different topic , than the efficiency it runs at while it is running .. 20% efficiency for 1 hour or 20% efficiency for 20 hours .. 20% is still 20% .. aka your night time reference.

Similar to .. a 1HP ICE running at 20% efficiency puts out less power than a 100HP ICE also running at 20% efficiency .. but again , 20% is still 20% .. aka your not 100% sun shine reference.

These two points are why average solar hours (at 1 sun) for a given location are researched and published base case figures in the solar industry. A good PV professional would do a site survey to identify how much (if any) specific site conditions would reduce that base case .. used to be calculated by hand .. today this is often done my computer.

Originally Posted by jeff5may

A heat pump isn't a free energy machine.

It isn't free in the absolute sense .. but , I don't care about that .. 'free to me' is what maters to me .. and in that sense .. yes they are 'free to me' energy machines.

If I invest 100 watts of electricity input into a heat pump operating at 3 COP , getting out 300 watts of heat output .. that is 200Watts 'free to me' .. those 'free to me' 200watts did come from somewhere else .. ie taken from the 'cold side' .. but I didn't have to pay for them , I only paid for the 100w input.

Originally Posted by jeff5may

Why do you think that efficiency numbers have constantly been improving over the years?

Like allot of things supply and demand.

Originally Posted by jeff5may

Speaking of heat pumps, here's my heat pump of the week.

Originally Posted by jeff5may

You need to be using a dehumidifier or refrigerator compressor for the HRV for a single family home or smaller dwelling.

No .. 'need' is definitely the wrong word.
I actually do not 'need' to do that.

You are welcome to make any system you like .. I already posted why I will not be using using your heat pump HRV suggestion .. so far you have not addressed those cons of this suggested approach.

[jeff5may]

I'm not the guy who will arm wrestle you in the armchair over a keyboard. Go ahead and believe the regional sales executive on salary vs commission, and the program they wrote to keep you from being diligent. Solar City and Tesla will hook you up right quick, all it takes is a second mortgage or a green new energy offset contract (probably tied to the deed as well). No homework, warm fuzzy feelgood, minor inconvenience of recurring monthly payment. Fully prorated manufacturers warranty, certified and insured to WTO standard 666. Somebody's gotta buy that, might as well be not me.

I am the guy who overbuilds, super insulates, and oversmplifies the stuff back to the era where all this stuff was painted brown and beige. In my garage, with my hands, bionic like the six million dollar man, while you wait, watch, or check back in. The scrap kings stop by and we swap stuff, or Facebook or a previous Facebook customer alerts me to something for nothing (or next to nothing). Might not be 27 SEER, definitely not 2700 dollars. Closer to 27 my cost, 100 to a cohort or someone with a trade, sorry can't help you for the beat down beggar with 16 kids.

I'ma spoil the HRV thing for you. The "mystery matrix" is zero dollars. Go behind sam's club, costco, or another super box store shortly after "event weekend", and stuff your van full of commercial grade coroplast. Might wanna ask before you grab the structural shiny frame stuff, though. Build a couple or three plastic sandwiches about a cubic foot each. Run whatcha brung. The fans in broken dehumidifiers all work.
Read this:
https://ecorenovator.org/forum/showthread.php?t=891

Oh yeah, the factor of 10 thing. 10 times smaller, 10 times cheaper, 10 times more likely to work when you plug it in. As always, value is in the eye of the user.

[jeff5may]

Next, the pv solar. Your sunpower panels are rated at 200 watts per square meter, peak output. Going with your 4 hours of sun per day, this gives you an average figure of 33⅓ watts per square meter. Mother nature will step in and reduce your average down towards the 25 value I previously cited. Fwiw, I hope you get 30.

If you're going DC with the solar array to the battery bank, pick or build the best charge controller you can. Same situation as upsizing plumbing to combat back pressure, make it stronger than the source. Something you only want to build or buy once, set it and forget it. Drive it like you stole it on autopilot until the batteries wear out, change batteries, repeat.

If you're using an EV battery pack, use the built-in liquid cooling to help heat your thermal store. Rig up a thermosyphon and consider harvesting heat from the charge controller as well. If it's all indoors, it might not matter. Electrical efficiency vs thermal power generation.

[IamIan]

Originally Posted by jeff5may

while you wait, watch, or check back in.

Please refrain from making Ad hominem personal attacks toward me , like that.

You do not actually know my life .. what I do , how I spend my time .. what I've done .. etc .. and even if you did , such would still be irrelevant to the discussion/project here.

Originally Posted by jeff5may

I'm a spoil the HRV thing for you.

You did not spoil anything for me at all. None of what you wrote there is relevant to the objections/issues I previously told you were why I will not being doing the heat-pump HRV you suggested.

[jeff5may]

Ad hominem, hahaha now I really feel old! I apologise if I hurt you somehow trying to offer practical suggestions. See ya round, good luck in your endeavors.