Heating and Air Calculations

[trekdave42]

All,

I'm full-timing aka geo-baching for the next year. The campground I'm staying at gives a $100 credit each month for the monthly rate. Just computed my estimated monthly usage during the summer months, but need some help for the winter months. I'm looking for calculations / burn rates / LP gas used for the furnace during the winter. Doubt I'll use the heat strips much being that at certain outside temps they will freeze up, but curious how long my LP gas will last (2011 BH390h). Understand this is hard to calculate depending on the temperature outside and what someone considers a comfortable inside temperature. Feel free to post your estimates for LP usage based on your furnace settings.

AC calculation based on 13,500 BTU:

15amps x 120volts = watts/hour

Watts/hour x 24 hours x 30 days = watts per month

Watts per month / 1,000watts = kW per month

kW per month x .1025 (cost of buncombe county kW) = $132.84

Note: This is assuming that the AC will run 24 hours a day for an entire month.

-David

[JTN8]

During the winter months, I'd use a couple of electric space heater instead of your propane furnace. When I dry camped this year at Daytona for the 500, I went through almost a full tank of propane due to the cold weather. In the ten days we were there, it cost me about $75 In propane. Our furnaces will eat up some propane! I'll place two electric heaters, sometimes three depending on the temps and who's with us. If it's below freezing out, I place two utility lights in each side of the wet bays (one buy the pump and one by the water manifold) to keep them from freezing since I don't run my furnace if I've got power. I also place an external thermostat In the wet bay to monitor the temp. Last winter, low 20's and the two lights kept it around 43 down in the wet bays.

Hope this helps a little

Jason


Sent from my iPad using Forest River Forums

2014 Berkshire 390BH
2011 cadillac SRX

[speedmerchant]

Originally Posted by JTN8

During the winter months, I'd use a couple of electric space heater instead of your propane furnace. When I dry camped this year at Daytona for the 500, I went through almost a full tank of propane due to the cold weather. In the ten days we were there, it cost me about $75 In propane. Our furnaces will eat up some propane! I'll place two electric heaters, sometimes three depending on the temps and who's with us. If it's below freezing out, I place two utility lights in each side of the wet bays (one buy the pump and one by the water manifold) to keep them from freezing since I don't run my furnace if I've got power. I also place an external thermostat In the wet bay to monitor the temp. Last winter, low 20's and the two lights kept it around 43 down in the wet bays.

Hope this helps a little

Jason


Sent from my iPad using Forest River Forums

2014 Berkshire 390BH
2011 cadillac SRX

Doesn't your Berk have the heat pump systems built into your roof a/c's? Mine does. They heat the coach just fine down to 32 degrees. Haven't tried them at colder temps but some say they are still good below that. Saves buying space heaters....

[JTN8]

Originally Posted by speedmerchant

Doesn't your Berk have the heat pump systems built into your roof a/c's? Mine does. They heat the coach just fine down to 32 degrees. Haven't tried them at colder temps but some say they are still good below that. Saves buying space heaters....

I do have both front and rear heat pumps and also have used them down into the 30's... Once you get below freezing they end up going into reverse mode because they freeze over. Once they do this, you pretty much lose them until it worms up outside because they really can't warm the coach that well anymore. I've noticed during the daytime and it's sunny they will work just fine below freezing but when it gets dark out and colder they just can't keep up. My old coach had the Coleman heat pumps and they worked better in the cold then the dometic's do (just my opinion). The space heaters are only about $20 a piece and three of them keep the entire coach at about 70 even in the lower 20's. The other nice thing about them is you can not here them at all!! I also bought the electric fireplace / heater on sale at Lowe's that is in the picture I attached. Heats the entire living room and looks nice too.

Jason


Sent from my iPad using Forest River Forums

2014 Berkshire 390BH
2011 cadillac SRX

[Myrle]

[QUOTE=trekdave42;889726]All,

I'm full-timing aka geo-baching for the next year. The campground I'm staying at gives a $100 credit each month for the monthly rate. Just computed my estimated monthly usage during the summer months, but need some help for the winter months. I'm looking for calculations / burn rates / LP gas used for the furnace during the winter. Doubt I'll use the heat strips much being that at certain outside temps they will freeze up, but curious how long my LP gas will last (2011 BH390h). Understand this is hard to calculate depending on the temperature outside and what someone considers a comfortable inside temperature. Feel free to post your estimates for LP usage based on your furnace settings.

AC calculation based on 13,500 BTU:

15amps x 120volts = watts/hour

Watts/hour x 24 hours x 30 days = watts per month

Watts per month / 1,000watts = kW per month

kW per month x .1025 (cost of buncombe county kW) = $132.84

Note: This is assuming that the AC will run 24 hours a day for an entire month.

-David[/QUOT

We only use electric ceramic heater it heats over 300 square feet nm easily. I try to use as much electrical stuff as I can since this comes with the nm camp site.

[speedmerchant]

Originally Posted by JTN8

I do have both front and rear heat pumps and also have used them down into the 30's... Once you get below freezing they end up going into reverse mode because they freeze over. Once they do this, you pretty much lose them until it worms up outside because they really can't warm the coach that well anymore. I've noticed during the daytime and it's sunny they will work just fine below freezing but when it gets dark out and colder they just can't keep up. My old coach had the Coleman heat pumps and they worked better in the cold then the dometic's do (just my opinion). The space heaters are only about $20 a piece and three of them keep the entire coach at about 70 even in the lower 20's. The other nice thing about them is you can not here them at all!! I also bought the electric fireplace / heater on sale at Lowe's that is in the picture I attached. Heats the entire living room and looks nice too.Attachment 79610

Jason


Sent from my iPad using Forest River Forums

2014 Berkshire 390BH
2011 cadillac SRX

Good info about the pumps freezing up. I haven't had that happen yet and hopefully won't have to experiment with that!! Love the fireplace and love your 390BH. Sweet ride!!

[Phil57]

Jason I love the fireplace. I wish we would have had one when emergency bought the MH. That's about as close as we can get.
When full time also and when it gets cold we run a even pure type heater. Not sure the brand but they were popular a few years ago when fuel was so high. I got a deal from one of my customers. I would never pay the price for one but it was a good deal. I had forgotten about it until we were cleaning out a storage unit and now it is with us all the time. It and a small fan heat the entire MH and it's very quiet. At night the heat pump is ok and we use it also but it to noisy.

[pmsherman]

Your calculation for AC costs would be accurate if the compressor runs continuously. If you assume that it cycles off, especially at night, costs will decrease.

The biggest problem when using electric space heaters (note plural form) is finding places to plug them in. My 2011 Georgetown has almost all of the AC outlets wired to a single 20A circuit breaker, making it impossible to run two heaters at the same time. The only outlets that are on a separate breaker are the three GFCI protected ones, two at the sink and one in the bathroom.

One way to improve efficiency of heating, especially at night, is to close all of the slides except the bedroom. This cuts the surface area that radiates heat and makes it easier to warm the inside. I also discovered that the engine run AC/vent control needed to be set to "Max Air" to close the outside air intake. This is an electrically controlled mechanism in my Georgetown and operates with the ignition switch off.

If you don't have double pane windows, bubble foam insulating material over the windows will also make a good improvement.

Phil

[Herk7769]

Does your cost per KWh the total cost or just the electric?

Seems a bit low when you include "transmission cost per KwH" and "taxes and program fees"

For example, my "electric generation cost" is 8.18 cents per KWh but I need to add 0.9 cents for "Transmission" and 6 cents more for Distribution for a total cost of 15.8 cents per KWh

Then I need to add the "Customer Charge" of $7.25 flat rate per month and State Taxes of about $6.00 per month.

[JTN8]

Originally Posted by pmsherman

Your calculation for AC costs would be accurate if the compressor runs continuously. If you assume that it cycles off, especially at night, costs will decrease.

The biggest problem when using electric space heaters (note plural form) is finding places to plug them in. My 2011 Georgetown has almost all of the AC outlets wired to a single 20A circuit breaker, making it impossible to run two heaters at the same time. The only outlets that are on a separate breaker are the three GFCI protected ones, two at the sink and one in the bathroom.

One way to improve efficiency of heating, especially at night, is to close all of the slides except the bedroom. This cuts the surface area that radiates heat and makes it easier to warm the inside. I also discovered that the engine run AC/vent control needed to be set to "Max Air" to close the outside air intake. This is an electrically controlled mechanism in my Georgetown and operates with the ignition switch off.

If you don't have double pane windows, bubble foam insulating material over the windows will also make a good improvement.

Phil

Good thing about our Berkshire's is that all of our outlets are not wires together! I tested them all and figured out I can actually run three heaters in the living room alone if I wanted and they'd all be on separate circuit breakers. The one under the TV cabinet is on the same as the fridge, the ones in the kitchen are on there own GFCI, and the ones by the driver and passenger seats run off the bathroom GFCI and then the ones in the bedroom run off the CB for the inverter so they are on a separate one too. So realistically we could run 4 heaters and they'd all be on separate CB's.

Jason

[Myrle]

Originally Posted by pmsherman

Your calculation for AC costs would be accurate if the compressor runs continuously. If you assume that it cycles off, especially at night, costs will decrease.

The biggest problem when using electric space heaters (note plural form) is finding places to plug them in. My 2011 Georgetown has almost all of the AC outlets wired to a single 20A circuit breaker, making it impossible to run two heaters at the same time. The only outlets that are on a separate breaker are the three GFCI protected ones, two at the sink and one in the bathroom.

One way to improve efficiency of heating, especially at night, is to close all of the slides except the bedroom. This cuts the surface area that radiates heat and makes it easier to warm the inside. I also discovered that the engine run AC/vent control needed to be set to "Max Air" to close the outside air intake. This is an electrically controlled mechanism in my Georgetown and operates with the ignition switch off.

If you don't have double pane windows, bubble foam insulating material over the windows will also make a good improvement.

Phil

That is why take. Extension cords you to plug into pedestal. I use one of those water weines cut it to length then split it and when I run the cord through window it seals it. I also use them cut pieces about 6"n long 45 them and piput them on corners of slides saves head bumps.

[gkelter]

We run extension cords out the bottom of the slides and plug them into the pedistal