We have 2 --1000 gallon tanks above ground in ND and they go thru the winter fine. We are a duplex with electric appliances, get summer fill, with special rates on electric. (off peak). Not sure if you can put can bury propane tanks. We also have a back up generator. Our temps last winter got down to 21 below without a problem.

The info you provided isn't enough to size the propane tank. You also need to consider the scenario and what applainces will be running at the same time and for how long.

The big drivers will be the heating system, freplace, generator and hot water. Find out the gallons per hour ratings for each of these and multiply by the number of days you need. Keep in mind that the propane tank is only filled to 80% of maximum capacity to allow for expansion, so a 500 gallong tank will only have 400 maximum gallons; 1000 gallon tank has 800 gallons. Also- you need to figure that when an outage occurs you probably won't have a full tank.

I looked at the Kohler 15kW specs and it is rated for about 1.5 gallons per hour of propane usage at a 50% load (idle speed). A 2 week outage would use over 500 gallons assuming you ran the generator continuosly for that entire time. So that alone would put you in the 1000 gallon tank class.

But I would really think hard about this 2 week requirement. If that is what you really want - then you probably would need a generator that is liquid cooled and not air cooled (air cooled are cheaper). The liquid cooled gensets may consume more fuel - check the specs. 2 weeks of continuous operation is a long time on a genset.

I worked out the tank capacity with the propane service provider. They not only sized the tank, but they also provided a special valve to ensure that the pressure was regulated when the genset is running. The tank size won't change the gas pressure coming into the house since it the regulator keeps the right pressure.

I would also look at the genset size. Since your hvac is gas, you don't need a lot of power to keep the house comfortable and rive all of you appliances and well pump. A smaller generator will use less fuel and will be cheaper to install. I have a 12kW Kohler unit and it is more than enough to run the house during an outage. We live in VA and have had some long outages - over 24 hours with no power with near zero degree temps is a long outage. The 12kW works like a champ.

Also - make sure you get BOTH the carburetor AND batttery warmer heater accessories for your genset. These are a must in cold weather and will make sure the unit starts in very cold weather.

sniffdog, thank you so much! the 2 weeks was not a hard & fast rule - just a WAG. valuable info the rest - thanks again. have already passed this on to DH..... I post, he calculates.

No problem. You might want to call Ziller Electric which is where I bought my generator and automatic transfer switch (and the heater accessories).

I got some quotes from local companies to have a genset and the elctrical put in and they were very expensive.

I wound up doing all the work myself and saved a bundle. I think the total cost for all parts, transfer switch and genset (with shipping) was around 5 grand. That was for a Kohler 12kW generator.

Based on the research I did, and posts on the elctrical forum, i concluded that Kohler and Cummins Onan made the best residential gensets. You can buy the Cummins at Costco but Kohler has to be purchased via a dealer. There are a few on-line dealers like Ziller but not many.

When you make your selection, make sure that you can get service locally. I do all of the routine stuff like oil changes, but if something big fails you will need a service tech to come out and fix it. I wanted a Cummins but the nearest dealer was 200 miles away.

Kohler makes a great unit BUT they really make it hard for the handyman to do things. For example, you cannot buy the service manual through any of the dealers. However, there are ways to get around that. I found a parts supplier on line (MPG Small Engine Parts) and they will order me anything I need including the service manual.

So do your homework before you purchase. Beware of the units sold at the Big Box stores like HD and Lowe's. In the case of Lowe's, they offer a Kohler unit BUT it was specifically made for Lowe's and doesn't have all the features that the dealer sold unit has. In fact they have slightly different part numbers (the Lowe's unit has a -L after the number) to refelect that it is different.

I believe that the Cumminis units sold at Costco are the real deal but you need to check to make sure.

There are a lot of posters on the GW electrical forum who know generators. I suggest posting questions over there to get more details.

Good luck.

I had the same scenario in Maryland and i used 1500 gallons of propane consistently for 7 years. We had a 1000 gallon tank and had deliveries three times a year
4500 sqr ft 1 professionals working from home. No kids three levels including basement. Propane heat- water-stovetop dryer-fireplace