propane generators

Henry

A while ago ther ewas a thread about problems with propane generators. I had a heated conversation with a propane supplier regarding the need of a1500 gallon tank for a 30Kw generator. Many of thepropane suppliers do NOT know their propane code. In Canada it is B149.2 Propane handling & storage. To help people choose the proper tank, we have put in the annex Table J.9. It clearly shows the tank size neede by BTU and OUTDOOR temperature.

lchmb

The problem

The big problem between generators and suppliers is the usage. A generator come's on once a week for 10 minutes and use's next to nothing. Depending on the area, it may have usage once or twice a year and run for a day. So the cost versus's profit is nil. Now tell a customer that yes you have a nice generator, but you will need to purchase a 500 or 1000 gallon tank and here's the cost, you better be ducking. On top of appearance and setup cost's....:/

I can take you to 50 home's off the top of my head running 13,14 and 15 Kw generator's off (1 or 2) 120 gallon tanks. And no, not saying it's right...I do know how to size for BTU and temp... 

Charlie from wmass

People think codes are optional

These charts and columns were not taken from thin air or guess work. Just because it is done that way does not make it right or safe. If they need a 2000 gallon tank I tell my customers and do not duck. That tank will ice up just when they need it most. Then you can duck as the lawyers start throwing papers at whoever worked on it last with a license.

lchmb

curious

I dont disagree with you at all Charlie..Curious as to what happens in Mass? Do your supplier's require the customer's to purchase the tanks, do they require them to meet full BTU load? Do you have an inspector who verifies the tank for the load?

icesailor

LP Tank Sizes:

That's not a very professional view to take. I've done a lot of restaurant work and where I work, it is all LP gas. As they added equipment, in August, when the restaurants are busiest, the tanks would ice up so badly that they wouldn't vaporize. The gas pressure would drop and the burners would go down in output. The ice was 1/2" around the tanks below the liquid level. The kitchen staff gets ugly. The solution was more tanks to increase the vaporization/boil off area.

There is a building where I work that was built new and has a 1,000,000 BTU boiler. They buried 4-1,000 Gallon tanks in the ground. The first winter they left the heat on, they kept getting flame failures in the night. It would start up and run fine when re-set. The problem turned out to be that they were depending on the heat of the ground to help with vaporization. But the ground around the tanks had frozen solid. The frost in the earth was acting as an insulator. They could have switched to liquid but that has it's own problems.

Those installers who connect a 15K generator to a couple of 100# cylinders and test it once a week may be in for a rude awakening when there is an ice storm in January and the power is out for days and they (a.) can't get a delivery or (b.) they can't vaporize the gas and they are lucky to get 8 KW out of the unit.

Under size at your peril.