Replies

1. 
   _mj_ | Nov 11, 2022 04:15pm | #1

   I have 2 Fujitsu Halcyon systems installed. One has 3 interior units, the other has 2. Both have the cold/hot option built into them. I use them for AC all summer and the occasional heat in the bedrooms during the transitional seasons, like right now here in NYC when I have not yet turned on the gas/ hot water heating system. (This is the latest THAT's ever gone!)

   Next week I'll turn on the furnace and the ACs will be waiting in the spring for when I need them again. If you don't wire them into your primary thermostat you can just run your boiler as you always have. I don't see a reason you would HAVE to use them for heat if you chose not to.

1. 
   joejoyce | Nov 13, 2022 09:51pm | #6

   Thanks for your reply. I may contact an installer who uses Fujitsu vs Mitsubishi (which is the brand the contractor stated he'd install).

   It doesn't seem logical that there would be no option to use them just as ac vs a heat pump.

   How old are your Fujitsu? Do you find the compressor quite when it is running? Also, is it attached to your building on sitting on a pad on the ground?

   Thanks for your input.

2. 
   rusty_tools | Nov 11, 2022 08:45pm | #2

   I checked into Rheem and Carrier for my shop a few years ago. Both offered AC only or Heat Pump and AC which was backed up by electric resistance heat. Think a base board heater in front of the coils, it's quite the same but the same cost to operate at the point the heat pump stops. By the way I was told that would be between 15 and 20 degrees here in Ohio. I passed on it because of the cost and I was told I would void the warranty if I made my own air box with a 20"X20"X5" pleated HEPA filter. I felt that after a couple of weeks of woodworking the little screen that pasted for a filter and the coils would be packed with dust.

   I think if I were you I would look at keeping the oil furnace, if it's still good. You could put in a heat pump and heat with it, as far as it can go, and save what you could from its' higher efficiency. Then rather than the strip heat coming on the oil furnace could take it the rest of the way. Your contractor may not want to but I can't see any reason why when the temperature gets low enough for the strip heat to come on, it couldn't fires the oil unit instead. Natural gas is the cheep fuel here but a heat pump is a lot more efficient at more moderate temperatures so anyone that can get gas goes with a heat pump with gas back up for lower temps.

   Hope this gives you some ideas.
   Be safe and have fun.

3. 
   rob_ss | Nov 12, 2022 02:29am | #3

   Changing from oil to electricity is in principle A Good Thing.
   The problem is of course that in cold climates, electricity is more expensive.
   Heat pumps are by and large a lot cheaper to run than oil, and of course are far less environment-munting. Even if powered by coal generation, they are still far more efficient that using the coal to heat your home directly.

   It is absolutely possible to have both small units in rooms and a central heating system. We do just that though use pellets rather than oil which are a bit more effort and they take up 4 times as much space for storage than diesel. Still, a lot cheaper to run even so.

   The key is never to use the evil 'auto' setting as the heat pump will try to cool your room if it exceeds the set temperature so you can end up pumping the heat out of your house. Good in Summer, in Winter, not so much.

4. 
   john_c2 | Nov 12, 2022 02:32am | #4

   I'm in eastern MA. Heat was always oil, forced hot water. A couple of years ago I put in 2 minisplit heat pumps, one with 3 zones, the other is 1 zone.

   The minisplits are still cheaper to heat with than the oil. Even with recent electric rate hikes. Oil right now is $5.79 a gallon.

   The coldest it's been here is a few degrees below zero, and the heat pumps still work fine. But when it gets into the teens or below I turn the oil heat on. The miniplits don't heat the cellar, where all the pipes are, and I'm worried about pipes freezing.

   I don't know why they can't set it up to keep your oil heat. Is it because the rebates and other incentives require the heat pumps to be the primary heat source? There is no physical reason you can't use both. You had both systems running independently before, right? This should be no different.

   I saved a lot of money last winter by not using as much oil. I'll save even more this year with these crazy prices. Remember, heat pumps are much, much, much cheaper than the old induction electric heat. You can't compare the two at all. If I were you I wouldn't hesitate to make the new units heat pumps instead of AC only.

5. 
   rusty_tools | Nov 12, 2022 09:00am | #5

   Your question isn't totally clear to me as to what you are asking. Also electric companies offer incentives to use all electric products and that maybe pushing your contractor in one direction but he should be up front with you if you ask.

   Clean air regulations very and could restrict what is available in your area but if new oil units are still being sold you should be able to keep yours.

   Like several people have said, Heat pumps are the most efficient up to the point that the resistance heat, also called strip or backup heat, comes on. So the trick is to get the cheapest backup heat. Like I said above, here in OH that's gas. If oil is your best deal at temps below the operating point of a heat pump and MA still allows it. And if you want to use mini splits so you can zone your system, I would look for a contractor that would talk about using your existing unit for back up heat. The other thing to think about is the age of you existing unit. You don't want to bother putting everything together only to have to replace your old oil unit next year. If you don't need to zone your house and just need a new HVAC system, see if you can get a Heat pump with an oil furnace back up. Oil hasn't been much in use around here in the last 50 years so I don't know much about it. In the past 40 years gas has made big advances in efficiency. New oil units may be much more efficient than the one you have. It's something you need to look into. That said the Heat pump will still be more efficient at moderate temps. But you might want to replace the old oil unit with a new one for efficiency reasons.

   Do your research, if oil is the cheapest back up find someone that will work with you. Part of that research is checking out the people you are working with. Make sure they are qualified and experienced enough to offer you good advice and give you a product that will satisfy your needs. There is always someone that will wire your house with paper clips at a great price but you won't be happy with the result.

   Good luck, hope this might clear things up for you.

1. 
   joejoyce | Nov 13, 2022 10:00pm | #7

   I might not have been clear as I am still trying to figure this out. But basic question is: if I have a Mitsubishi or Fujitsu heat pump installed (meaning a/c splits that cool or heat as needed), am I forced to use the heat pump or is there an option (like a switch or other mechanism on the splits) that allow me to only use it for a/c?

   If I pursue a rebate, then I am forced to use heat pump as the primary heat source. But if I don't pursue a rebate, then it seems to me I should have the option with whatever brand is installed to use the heat pump at my discretion.

1. 
   rob_ss | Nov 14, 2022 02:18am | #8

   There is no physical reason why you cannot use two forms of heating. We do this - our living room is heated by a log fire, but occasionally we boost heat with the heat pump, and in Summer, we occasionally use it for cooling. Ditto for hydronic central heating.
   As I said above, the only real no-no is using it on Auto mode when you are heating with another system.
   If you are required to remove your other furnace in order to get cheaper heat pumps then obviously you can't then use it as it will be gone, but otherwise you will be ok.

   Consideration needs to be given to the total costs, convenience and of course the environmental issues:

   There will be a temperature point at which your heat pumps will be more expensive than burning stuff to stay warm. You will need to assess this and decide if this matters enough to you - maintaining a burner is not free, and for most users the small savings for occasional use will be wiped out by the additional costs of keeping a secondary system going.
   Any savings you may make using oil or gas have to be balanced against the contribution you are making to climate change. If everyone who can use alternatives today does, climate change will be slowed, perhaps enough to make a difference we will all notice.
   Heat pumps are also very quick to heat a room, very easy to use and for us are cheaper than burning logs unless we can score free wood. Maintenance is near zero, just needing a filter clean every 3 months or so and a blow out with (gentle) compressed air every year or two. Lifespan is usually around 20 years.

   You can't run heat pumps off a generator though - well, you can, but it's a rare genny that will output that much juice. A burner needs power only for circulation and control so can usually run off generation or battery for a long time if your power supply is limited. Remember that in the Zombie Apocalypse, oil will also be impossible to get so prepping for long term power losses is probably pointless. A flaky electric grid might push you to keep the alternative for a while.

   All that having been said, you might be asking why I have hydronic central heating. Wife 'does not like heat pumps' 'they are blowy' - really the reason is that the controls are a bit intimidating, she does not understand them and is not interested in finding out. To be fair, when we have our heat pump on, it is usually blowing hard as we are using it to boost heat or cool the room. Once the temperature is stable there is little to no draught and the noise is inaudible.

2. 
   john_c2 | Nov 14, 2022 04:16am | #9

   Do you have to remove the oil burner to get the rebate. If yes, skip the rebate.

   If no, have the heat pump be the primary, and switch it back to oil as primary afterward. It really should just be wiring at the thermostat.

   But seriously, if you have to replace your current AC units, you'd be nuts not to replace them with heat pumps. You'll get AC as before, and heat when you want it. And this time of year the heat pump is much cheaper to heat with than oil.

6. 
   mcconoughey | Nov 14, 2022 11:34am | #10

   I started out, 35 years ago, with electric wall panel heat. It was costly to operate in winter and did not cool in summer. Then I added a small diesel fuel heater. It worked well and still does but I was still hot in summer. Now I have a minisplit air to air heat pump. Mine is AirCon but other brands are similar. Do check for variances in efficiency. The minisplit is very quiet, very efficient, heats or cools, and the inside blower unit lives inconspicously high up on an inside wall. It is the perfect solution and even comes with a little hand-held remote control device. Go for it!