Supplemental heat when we are away
We are about to start construction on our new home in Zone 6B upstate NY and are going to be putting in a 3 to 1 Mitusbishi mini split with two units ducted downstairs (living and master bedroom areas) and one wall or ducted unit upstairs. The house is 2,700 sf. with heating of ~13,000 BTU needed. The system should still provide enough heat at 17 degrees (16,000 BTU) and we plan to our wood stove for backup heat if it drops below 17 degrees or if the power goes out.
Our question is what if we leave for an extended vacation of more than a few days in the winter and the temperature drops to below zero for a week? We would not be there to run the wood stove.
What inexpensive source of heat could we have as insurance for this situation? I don’t want to add an ugly electric baseboard for a once in 10 year event.
Thanks
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Based on your heating load it sounds like this is a Passive House - or at least close. They don't get that cold - even if your heating system breaks it may never get below 50F.
That said, I've struggled with the same problem - those very few, but very cold hours when the split system's capacity is at its lowest. Some (maybe all?) Mitsubishi units have an option (called "CN24" on the control board) where they'll turn on an external heater (via a relay) when their output drops - but you still have to pick a heater. There are radiant panels that don't look too bad, eg eHeat. But it's still something you look at but may never use.
I'd plan on where you'd put such a thing, and rough in the wiring, but maybe hold off until your first winter. Turn off the heating one night and see how cold it gets - I bet you'll be surprised.
Or just buy a 1500W plug-in electric heater with a thermostat and set it at 55...but I don't like to trust those things when I'm not around.
Elizabeth,
I don't think your house will freeze if you are gone, but if you are worried, buy an electric space heater. You can put it away in a closet when you aren't on vacation.
Yes, it's a near Passive House, we'll see when it's finished. I didn't know about the CN24 feature. The eheat looks like a nice unit but at 475 watts how many would I need?
Like Cramer I don't trust those space heaters when I am not there. Maybe an oil heater. I think they are safer.
I'd put in a Cadet wall heater
http://www.cadetco.com/show_product.php?prodid=1051
Elizabeth,
To know how much much supplemental heat you would need I'd need to know the design temp for your specific location (though I'd guess 0-5F from your climate zone) and the specific models of the Mitsu equipment you're planning on (I'm guessing the 2.5 or 3 ton outdoor units).
But all that's highly theoretical - I like Martin's advice - get something you can put in the closet until you go away. If there won't be pets around, and you're careful about placement (not near piles of magazines, the drapes, etc) a $50 plug-in with tip-over shutoff might be all you need.
Say what?...... and how do you use an electric heater if the power goes out? Do you keep a bunch of hamsters on wheels? ;-))
Armando,
Unless I'm mistaken, you are the first person who has brought up the question of a power outage. As I'm sure you know, most automatic heating systems require electricity, so if the power goes out, about 99% of U.S. homes will be without any heat.
If anyone is worried about this problem, however, they can install a propane-fired space heater with a through-the-wall vent. Several manufacturers make heaters like this that do not require electricity.
We have gas service. Can one of these gas units be hooked up to the gas service with a thermostat set at 50 degrees? That might be a good solution to cover the vacation problem and the power outage problem.
Gas today is better than splits. Your PGH home should need no back up IMHO. If the power is gone there for long I would call my caretaker to assist. The portable electric or a built in and you are all set or gas. Too many options, most are overkill again IMHO.
Hi AJ
What do you mean by 'gas today is better than splits" We are going with ducted and non ducted mini-splits because we get both AC and heat in one system and the ducting is minor. It seems to be the most cost effective way to heat and cool a near passive house that is somewhat spread out.
We will use the wood stove for backup and probably the portable oil heaters on a thermostat for when we are away. We might have gas piped to a central location so we have the option of a gas unit should we ever decide we need it.
Very good