Will my generator run a minisplit safely?
STEPHEN SHEEHY
| Posted in Mechanicals on
My new house will be heated with two minisplit heat pumps. Here in Maine, we have lots of power outages, so we’re also putting in a whole house standby generator.
I’ve been informed by the Fujitsu installer that we should not plan to run the minisplits off the generator when the grid power goes out. We also may install a heat pump water heater and maybe even a heat pump dryer. We’ll have some backup heat.
I have two questions:
1. Would the generator power damage the heat pumps or prevent them from operating?
B. If so, is there anything we could install in the circuits that would clean up the power such that the heat pumps will operate OK?
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Google clean power generators, They do exist.
Thanks, AJ. Looks like Generac's new Synergy 20 kw generator would do the job.
One thing to note when sizing a generator IMO. If fuel costs to run it matter then one should know that the 20K units of which I have installed use a lot of fuel. I try to get the smallest unit installed that will do the job with a whole house switch. In your case with electric HVAC the 20K may be needed though. For others with non electric heat or AC needs an 8-12K is fine.
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AJ: with electric heat pumps, dryer, water heater, induction cookbook, oven, etc., I'm resigned to a 20kw generator. The new Generac I mentioned above will operate will run at 2700 rpm under low load, instead of the usual 3600, supposedly saving fuel.
My present house has a 10kw generator that uses about a half gallon of propane per hour. Expensive enough when the power is out for a few days, but cheaper than a hotel and better than freezing in the dark.
Stephen, probably not much if a help for you as your posts show you have a pretty good rationale for the decisions you are making on your build, but to start some debate around the subject:
When generators come up with clients I usually discuss the range of options from a system where you don't even know there has been a power failure to the very basic go to the shed, get out the Honda, run extension cords etc.
Where things get interesting is in the middle ground. Running a list of essentials like a few lights, heat, refrigerators, pumps and a couple of electronics without running everything. Is the moving from this to everything worth the added expense? A lot depends on how frequent the outages are, but really the decision doesn't sit on any logical firm ground and is more of a lifestyle choice.
Malcolm: once we decided to go with an automatic generator that simply goes on when the power goes off, the cost of going bigger doesn't change all that much. Heat, well pump, fridge, hot water, microwave, lights, etc got us to a 10kw in our present house. Since the new house will be all electric, with grid-tied pv, we probably need 20kw. Even if we could manage with something smaller, the only major cost saving is in fuel consumption, as a unit with twice the capacity only costs a little more, with installation the same.
Our power goes out a lot, often for days at a time. In the last month we've been out three times, twice for 36 hours, once for just a few hours.
2gl per hour half load 4 gl per hour full load for 20kw gen.
3 days at 3gl x $2.5/g 24 hrs/dy= 216 gallons at $$$???? @$2.5 = $540/outage. 10 outages that long = $5,400 dollars folks... I just like splaining this to future big is better folks.... No problemo for the multi dollar crew... the rest of us... should buy 8-12K or even go portable...