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Heat Pumps, what are they
Uses a compressor to raise the temperature of a working gas
Takes the heat from that gas, and liquefies it in the process
Sends the liquid to another place to pick up heat, turning liquid back into a gas
Gas goes back to the compressor to start over again
Heat can be moved:
Outside to inside: Heat Pump in heating mode
Inside to Outside: AC / Refrigerator
In the same air flow path: dehumidifier
Power available in your home
Most homes have 100 or 200 amps of service
Some may have 400 amp, also known as Comed Class 320
Amperage x 240 volts = total Kilowatts (KW) available
100 amps = 24000 watts or 24KW
200 amps = 48000 watts or 48KW
400 amps = 96000 watts or 96KW
How much capacity do I have left?
You know your total capacity now
We need to understand how much is already in use
Allocated power can also be reduced in a few ways
Some houses may need service upgrades
This isn?t cheap, best case $4000
Standard method to calculate current load
NEC standard method for calculating load allocates power per square foot, kitchen and laundry circuits.
Add on additional power for fixed appliances
1500 square foot home would have a base of 5100 watts or 21.25 amps
Add on for garbage disposal, ceiling fans, sump pumps, dishwasher, microwave, range vent fan, bathroom fans
Basic additional equipment can easily add up to another 5000 watts, bringing you up to about 40 amps
Common gas appliances and the electric equivalent demand
Heating 10KW to 40KW
Stove 8KW
Oven 6KW (if separate from the stove)
Water heater 6KW (there are models that heat pump only that are less)
Pool heater heat pump models available
Clothes dryer 5KW
Vehicles usually gasoline, but we are trying to kick that too! 7 to 11KW
#note that this has nothing to do with energy usage, and everything to do with power allocation of the electrical service. Allocating power of the service doesn't mean you will ever even get close to this level at any point, however it is conservative by it's nature to make sure that the odds of anything going wrong is very rare.
Simple home demand, standard all electric house appliances, what you find all over the country
10KW from the standard stuff most homes have
5KW for a clothes drier
6KW for a water heater
8KW for a stove
6KW for a Heat Pump / AC with Nat Gas backup
35KW, 145 amps and you still have a gas furnace and no car charging
If you add electric backup heat that is usually at least 10, if not 20KW
NEC derates backup heat to 65%, so 20KW is 13KW in load calc
This brings up to exactly 200 amp service!
Then add a car!?
If your service is near the limit, then you can use a charging station that monitors your mains power feed, and only charges your car when you have capacity
Most of us have upgraded to LED lighting, so we tend to be under the 3watts per square foot allocated in the standard calculation
100 Amp service
Heat pump washer / dryer combo unit (included in standard)
Heat pump water heater without backup resistance 1.5KW
Stove 8KW
Heat pump / AC 5KW with gas backup
10KW of standard stuff
Car charger with load monitoring
You still have gas, but should have rather low usage
MUCH lower utility bills overall
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