BigPickleKAM t1_j9djgqr wrote

I went back to college in my mid 20's after not making it the first time around.

I was a much better student and got my monies worth a degree and career that allowed me to live the life I wanted.

I also noticed the older students like myself typically did better than average.

My mom was my inspiration she gave up her goal of a degree to support her family. But she went back starting at age 40 and took 4 credits a semester of night or online classes to finally get her degree at age 55! She missed a couple semesters here and there for various reasons but she did it in the end!


BigPickleKAM t1_j93vjdc wrote

Depending on the size of the building wood can have a better fire survivability rating than steel as wood beams take a long long time to burn through to a point of failure. While a correspondingly strong steel beam would lose its ability to remain rigid.


>A fire test conducted in 1961 at the Southwest Research Institute compared the fire endurance of a 7x21-inch glulam timber with a W16x40 steel beam. Both beams spanned approximately 43.5 feet and were loaded to full design load (approximately 12,450 lb.). After about 30 minutes, the steel beam deflected more than 35 inches and collapsed into the test furnace, ending the test. The wood beam deflected 2 1/4 inches with more than 75% of the original wood section undamaged. Calculation procedures provided in a new publication available from the American Wood Council, entitled Technical Report 10: Calculating the Fire Resistance of Exposed Wood Members, estimates that the failure time of the 7x21-inch wood beam would have exceeded 65 minutes if the test had not ended at 30 minutes.


Of course wooden beams large enough to build a modern sky scraper would be so large they would eliminate all interior volume making them a non practical choice. But for low rise apartments it can be a good choice.


BigPickleKAM t1_j5ak26b wrote

The why comes down to inertia both in the flywheel and corporate thinking.

I can show you all sorts of cost benefit analysis done in industry and if you get the tech right you'll come out ahead. But no one wants to guess wrong and be left holding the HD-DVD bag. While high pressure storage and sourcing hydrogen in bulk can be an issue. The simple changes to run a diesel in hydrogen allows a safety blanket for the MBA types making the call. Since they can be reversed easily.

Also the amount of rotational momentum in a ICE is quite useful in starting large hydraulic pumps etc. Totally can be overcome as well but just a point.


BigPickleKAM t1_j575cp0 wrote

This is my world.

And yes for a traditional diesel engine with a jerk pump you are right. Hydrogen wouldn't work.

However for newer larger diesel engines that operate on a common rail with electronic controlled injection switching to any compressed gas is quite simple.

Some changes to the injectors are about all that is required. Since gas can be injected at a much lower pressure to get a good flame front from the compression.

There are also changes to the fuel mapping for injection duration and timing.

If you're curious and have specific questions fire away.


BigPickleKAM t1_isch03l wrote

Yes there are many options with as many different functions as you can imagine.

Mine assists solar so on cloudy days and mornings etc it takes what it can from solar and then supplements from the grid if needed.

If I generate more power than I consume it feeds back into the grid and my utility pays me for that power (at a heavily discounted rate).

But mine has to monitor the grid side and open the grid supply breaker if the grid voltage drops below 220 volts for more than 50 milliseconds.

And it won't allow the grid tie breaker to close if there are less than 220 volts on grid side etc.

Since that requires a connection around the tie breaker to monitor grid side it has to be installed by a certified electrician. And the switch has to meet utility requirements for those variables.

The switch you describe would still need to monitor grid voltage and interlock with your solar or generator supply breaker so only one could ever be closed at a time. To meet the code where I live.

There are a couple of physical interlocking designs where one can't close the grid supply breaker if the generator or solar breaker is closed. They even come with a sticker saying it meets code. But when you read the fine print what they meet us that the Interlock doesn't modify your breaker panel in a way that takes it out of code. They specifically do not cover and device or system connected to the panel behind it.

My main point is that you can find some great value when shopping online depending on where the switch sells from. Lots of those switches do not meet requirements. Be very careful as you can hurt someone and or leave yourself open to liabilities if you install some sub standard transfer switch.


BigPickleKAM t1_isbylpj wrote

Depends on where you live but where I am doing that without approval of the utility is A BAD THING.

You can do it with their approval that is a proforma process provided you use one of their approved switches and it's installed by a certified electrician and a permit is pulled at city hall.

The reason and I agree since my father was an electrician is you don't want to back feed into the grid during an outage that is dangerous for the linesmen working the problem.

These days it's far too easy to buy a product online that has all the right stickers but isn't actually safe to use.