Generator options for homes with a heat pump

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ivsenroute

ivsenroute

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Florida
Does anyone have any ideas for customers who have a heat pump system in a northern climate when it comes to standby generators?

It appears as though the cost vs benefit is questionable when it comes to heating the house due to the kW usage. For example a recent heat pump that I looked at had 3 elements in the kit at 5kW each and this is before you take into consideration the fan motor, condensing fan motor, compressor, hot water heater (electric), septic pump tank, well, etc.

I think it would be easier to have pellet stoves installed so you can get a smaller, less expensive generator. In this case a 20kW Generac would not be big enough for what he wants done.

Thoughts?
 
I install a relay that locks out the emergency heat (the heat strips)(this can be done by a relay powered by generator only breaking the control wire for the heatstrip relay from the t'stat) so the load is compressor/fan only. If it gets cold enough that the compressor locks out their SOL. Usually try to talk them into a small gas wall heater for emergency heat.
 
ivsenroute said:
Does anyone have any ideas for customers who have a heat pump system in a northern climate when it comes to standby generators?

It appears as though the cost vs benefit is questionable when it comes to heating the house due to the kW usage. For example a recent heat pump that I looked at had 3 elements in the kit at 5kW each and this is before you take into consideration the fan motor, condensing fan motor, compressor, hot water heater (electric), septic pump tank, well, etc.

I think it would be easier to have pellet stoves installed so you can get a smaller, less expensive generator. In this case a 20kW Generac would not be big enough for what he wants done.

Thoughts?
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the heat pump doesn't have heat elements. The furnace does. The heat elements are for emergency heat if it's so cold outside that the heat pump isn't enough then the heating elements kick on.
 
My issue is that the home is located in a higher elevation that routinely has below 0 weather and I am still of the opinion that heat pumps should not be used above the mason dixon line.

I think there is a good possibility that the elements can kick on if the heat pump cannot keep up which can happen. I appreciate the input so far, I just want to take them into consideration for sizing.
 
The way I do it is either talk them into a bigger Generator or you can install a contact as Hillbilly said that will break the heat strip control wire when on generator power.

The generac transfer switches have a space on the right side of the transfer switch assembly ( not the enclosure, the actual transfer switch ) to mount a microswitch with C , N.O. , N.C.

Just intercept the the heat control wire from thermostat and run it thru the microswitch
 
480sparky said:
If the heat strips are on sererate breakers, just don't put them on to run from the genny.
Click to expand...
Usually with heat pumps the blower fan draws power off of the heat strip circuit, sometimes there are two circuits, one runs part of the heat strips and blower, the other runs left over strips. Could split out the blower, but then your messing with the internal wiring possible voiding the UL listing, manufactures warranty, ect. easier to break the control from the thermostat.I don't think the small Generac transfer switches have a provision for extra contacts, so a 120 or 240 volt ice cube relay is cheaper and easier. Wire it to fail open upon loss of utility, Use power from the voltage sense block in the transfer switch.
 
hillbilly1 said:
I don't think the small Generac transfer switches have a provision for extra contacts
Click to expand...


They do have one, most people don't realize it because Generac doesn't show it in specs.

On the right side of the transfer switch block, you will see 2 sets of 2 screw holes. These are pre drilled to match up to a micro switch perfectly. On the smaller Generac switches you have to loosen the block and turn sideways to install it.

They are there to allow the hook up of microswitches for the power master units, but you can just use the micro switches by themselves. look at page 6 of this spec sheet

http://www.guardiangenerators.com/PublicPDFs/0G0734.pdf


here is link also to a clearer pic of the power master. I have used this unit to alternate between A/C and Water Heater load under gen power on some installations. Although I don't think the OP really needs power master unit for what he wants to do

http://www.apelectricshop.com/showp...dian-powermaster-priority-load-control-system
 
A 20KW generator probably puts out between 30KW and 50KW of waste heat when running full tilt.

Companies are starting to sell 'combined heat and power' systems for residential use, but these are unproven systems intended to run full time as a furnace; I don't know if anyone is selling CHP systems that are only intended for backup power use.

-Jon
 
peter d said:
You really lost me there Marc....
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Yeah, there's no "delete", so that's what you have to do. Or, get one of these:

decoder_ring.jpg
 
ivsenroute said:
Does anyone have any ideas for customers who have a heat pump system in a northern climate when it comes to standby generators?

It appears as though the cost vs benefit is questionable when it comes to heating the house due to the kW usage. For example a recent heat pump that I looked at had 3 elements in the kit at 5kW each and this is before you take into consideration the fan motor, condensing fan motor, compressor, hot water heater (electric), septic pump tank, well, etc.

I think it would be easier to have pellet stoves installed so you can get a smaller, less expensive generator. In this case a 20kW Generac would not be big enough for what he wants done.

Thoughts?
Click to expand...
Cost eficiency as far as I was tought heat pumps are not cost efficient from temps of 55*f or below. They are used on a lot of job trailers though. Pellet stoves seem to be the way to go now as they will heat a small house for about 700 bucks a year so they say in ny. I just put one in Dads house. Pita direct vent hopper and auger to feed pellets. I am moving soon so it doesnt pay for me. A small 1000 sq ft house will probably use 600 gals to heat min for winter at 4 bucks a gallon. Pellet stove will pay for itself in 1 -2 yrs. Older houses w poor insulation HOLD ON TO YOUR CHECKBOOK!!
 
I spoke with the homeowner about a pellet stove and he plans on getting one in the future for the lower leve of this split level house (2007-08 construction) which should do nicely with this well insulated house.

As I stated before, I am not a fan of heat pump systems in my area but this is one issue that I was told the "new" heat pumps are great and work well in our climate. I am still doubting that.

I prefer a coal burner that burns rice coal because they burn at a much higher BTU but they have more ash than pellets. I had a nice Harman rice coal burner with an automatic feed and a 100# hopper that was about 90,000 BTU.

Anyway I am sensing thread drift so I will stop typing and wait for some more posts based on the original intent of the thread.
 
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