Originally Posted by gasman6674
In that case if you already have a quick disconnect plumbed into your system use that, If not I would plumb it as close to the outlet of the regulator as feasible the use the biggest id hose you can find. I have a little concern for the regulator btu capacity as I do not know what the max flow on these import unit are. Try it if you have frosting issues or low flame in the unit report back
I don't have a quick connect plumbed into the system yet. That's what I'm trying to do.
I too worried about the BTU requirements. Looking online at what others have posted, it is looking like about 30,000 BTU with the generator running at full power (it has an eco mode too, so can run at a lower output as well). My furnace is 20,000 BTU input. Not sure about the stove, but let's aim on the high side and say 3x9,000 BTU and 9,000 btu for the oven too. That's 36,000 BTU. So if I wanted to run the generator on high, all three burners on high, the oven on high and the furnace, all at the same time, I'd be at 86,000 BTU.
I haven't been able to find a changeover regulator that looks like the one I have on the internet and don't know what make/model mine is. However, looking on the internet, I wasn't able to find a changeover regulator less than a 130,000 BTU rating. They are probably assume if you are wanting to use them with multiple tanks, you are probably running a number of devices on them and will need the extra BTUs.
Having said all that, I'm most likely safe from the BTU perspective. However, as you pointed out, frosting is a problem and I believe it to be my biggest problem. I've never been able to find a vaporization rate table for 20 or 30 lb propane tanks online. I've always had to extrapolate based on charts that show rates for a 25% full smaller tank compared to charts that show rates for 100 lb tanks at various fill levels.
Doing this math again, I find that a full tank puts out *roughly* 2.8 times as many BTUs as a 25% full tank (temperature and tank size will affect this, but I'm just trying to get rough numbers). Using the charts that show BTUs for 20 lb and 30 lb tanks, I find that if I use a 20 lb tank, at 25%, at 0 degrees F (again, this time of year, this is being used for ice fishing, so 0 degrees is not unheard of and isn't even the worst case scenario), I'm at only 7,500 BTUs. 2.8 * 7,500 BTUs = 21,000 BTUs. 2.8 * 10,000 BTUs = 28,000 BTUs for a 30 lb tank (what I currently have in the RV).
Obviously, a tank is only 100% full for a short while once it is used, but it does give me a range of 28,000 BTUs when full on down to 10,000 BTUs at 25% and then lower before the tank is regarded as empty by the changeover regulator/valve and the switch is made to the other tank.
This means my furnace will not be able to run at full force and I'm not sure how it will handle getting less than 20,000 BTUs input. Any ideas? Will it cut out when we reach the max vaporization level of the tank at a rate under the 20,000 BTUs the furnace can handle, or will it just run at a lower input/output? I've seen space heaters turn off when they are set at a high output and the tank can't supply that output (due to being low or due to the cold, or both). Before doing the math, I hoped they had figured all this out and that it wouldn't be a problem using the furnace in cold weather. I have to hope the furnace can handle a lower BTU input and will just run longer, but I'd love to hear any information anyone else has on this.
Now, add in the generator, pulling another 30,000 BTUs at full power, and I'm probably going to have serious problems running in cold temps. I could get a regulator that allows me to use both tanks at the same time, doubling the surface area, and increasing my max BTUs. That kind of defeats the benefit of an auto changeover regulator, but if that's what I have to do in the winter, so be it.
Another option would be to use one of the propane tank heater products. They are quite spendy. And, of course, using electricity to run the power for the tank heaters would reduce my effective generator capacity and burn more propane.
All of this won't prevent me from converting the generator over. It may just mean that I can't run it off propane in the winter time on the same tanks that are running the furnace for the RV. If I have to carry around a separate tank (or tankS, considering I may reach a single tank limit quickly in cold weather if I'm drawing a lot of power out of the generator) in the winter and run the generator on that, I guess it is either that or retrofitting the generator to run off a larger gasoline tank. I'm just trying to avoid the gasoline if possible, for a number of reasons.
Thanks again for your insights.