Alternative heat source, minisplits for real?

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of the house.

Our constraints are primarily very-occasional high usage and long delivery distances. We have fourteen sinks, four toilets, three showers, two tubs, two dishwashers, and two clothes washers. Setting aside the fourteen sinks, I’d bet there are times (holidays/guests) when both dishwashers, a clothes washer, and three showers or a tub are all running simultaneously. We also have to deliver that water more than 100 feet, in some cases, thru mostly un-insulated copper tubing.
Because of the distance, we have the thermostat set higher than any HPWH can deliver, but that’s mostly a winter thing. .
You would probably need at least 2 of the 80 gallon models. My 50 Gal HPWH keeps up with a much smaller place and 4 people but i have to set it at max temp which is 140 and for high use times, i set it on hybrid mode so the resistance elements kick in as well to overcome the slow recovery times. The de-humidification does help cut down on the amount of time the regular dehumidifier runs but does not do the whole job. That said the electric savings MOST of the time is significant.
 
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Research and development. Am I showing my cards? ;lol

I mean, 14 sinks means you have a huge family and/or a nice job. I now understand how you make all of this energy stuff sound simple.
 
I check on this every year, and I’m due to check again, but I have never been able to find any HPWH solution that can handle reasonable demand with an indirect system. Do any exist today?

I’m running an Amtrol Boilermate on my oil-fired boiler, and I’ve asked a few HVAC contractors about adding indirect HPWH to the system, but they all say my system is about the best thing they see, and they woudn’t change a thing. What they are not acknowledging is the secondary factors, beyond direct operating cost:

1. The cooling and dehumidification benefits. My basement is not air-conditioned, but it is finished space that we use. It's fine thru the first half of the summer, but it can start to get a little warm down there by August.

2. I’m also burning almost $200/mo in running dehumidifiers down there thru summer, something that would be mostly or entirely offset by the HPWH’s dehumidification. Those dehumidifiers also pump a lot of unwanted heat into the basement.

3. My boiler is under our kitchen, and the floor between is not insulated. The kitchen is already the hottest room in the house in July, between having lots of glass, poorer insulation that adjacent areas, and cooking. Shutting the boiler down would help keep the kitchen from being warmer than the rest of the house.

Our constraints are primarily very-occasional high usage and long delivery distances. We have more than ten sinks, four toilets, three showers, two tubs, two dishwashers, and two clothes washers. I’d bet there are times (holidays/guests) when both dishwashers, a clothes washer, and three showers or a tub are all running simultaneously. We also have to deliver that water more than 100 feet, in some cases, thru mostly un-insulated copper tubing.

Because of the distance, we have the thermostat set higher than any HPWH can deliver, but that’s mostly a winter thing. I’d be happy with cooler water in summer, which is when those secondary advantages mentioned above can also benefit me most. This is why I only consider indirect an option, as I’d be decommissioning it every winter. Alternatively, if there were one that could be set up in tandem with the boiler to run all winter, that could work... but again, we’re then talking two tanks?

The only indirect systems I found go into the DHW loop on a boilermate, via coaxial dip tube. This won’t work, as the restriction of going coaxial on the dip tube would kill our delivery volume. We need at least 3/4” thru the whole system, given the number of simultaneous appliances. I’d be happy going with a commercial unit, as long as we could find one that’s single-phase on the mains supply.

What is your summer oil consumption?
 
I mean, 14 sinks means you have a huge family and/or a nice job. I now understand how you make all of this energy stuff sound simple.
For full disclosure, I mis-counted the sinks, there are presently only 12. You probably also have more than you’d think, until you sit down and actually count them.

What is your summer oil consumption?

I’ll need to verify this on my oil tracking spreadsheet, but my memory tells me it’s very close to 1 gallon per day. Our daily hot water use is probably not all that high, but it can be on occasions when we have guests.
 
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This video (and others) may be helpful for someone considering a self-install. What I like about this one is that he got proper training, made a mistake and corrected his mistake properly instead of taking shortcuts.
 
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I didn’t read all the posts here but Costco has this 18k BTU for $1100 if you want to diy. They have other sizes as well.

Mr Cool DIY 18K BTU Mini-Split Heat Pump with WIFI https://www.costco.com/Mr-Cool-DIY-18K-BTU-Mini-Split-Heat-Pump-with-WIFI.product.100409862.html

Also fwiw I paid $14k for a two compressor (4 head) system with a 12 year parts and labor warranty in western WA.
Not really concerned with ROI as I value the the air conditioning/zone heating. Also could not stomach the work of redoing the limited ducting in my 1922 home.
 
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I didn’t read all the posts here but Costco has this 18k BTU for $1100 if you want to diy. They have other sizes as well.

Mr Cool DIY 18K BTU Mini-Split Heat Pump with WIFI https://www.costco.com/Mr-Cool-DIY-18K-BTU-Mini-Split-Heat-Pump-with-WIFI.product.100409862.html

Also fwiw I paid $14k for a two compressor (4 head) system with a 12 year parts and labor warranty in western WA.
Not really concerned with ROI as I value the the air conditioning/zone heating. Also could not stomach the work of redoing the limited ducting in my 1922 home.

What brand did you get?
 
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Just remember the DIY ones are notably less efficient than the more "professional" units. Mr. cool is 16 seer, Mitshibushi one i had installed is 22 (some go up to 30). Actually, the higher installation costs i plaid WILL be recovered by the efficiency difference.

The big concern i had with the DIY units are the hose management. The spare hose is usually just coiled up next to the unit. Between dogs, kids, weedwackers, etc, I felt that the risk of pinching them (ruining efficiency or ruining the unit) would be high enough that the lifespan of a Mr. Cool versus the mitshibushi wasnt worth it. I figured I would do it once and do it right even though the up front cost was different. The difference between a 16 seer and a 21 seer makes the 21 seer unit cheaper over a 20 year life (calculated to be a savings of $2200 in energy use over 20 years). Note that when i priced them out, for the size and all i wanted, prices varied by 50%, some companies were just ridiculous (I paid $5 for 15k btu which works down to -15F, the low operating temperature was very important to me)!

Just wanted to point out that you really want to check lifetime costs, not just install costs. Buy a more expensive unit, you can even pay to have it installed, and its going to be cheaper in the long run, all the while you have better equipment to use. Just my experience as someone who paid to have it installed.
 
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I didn’t read all the posts here but Costco has this 18k BTU for $1100 if you want to diy. They have other sizes as well.
Mr Cool DIY 18K BTU Mini-Split Heat Pump with WIFI https://www.costco.com/Mr-Cool-DIY-18K-BTU-Mini-Split-Heat-Pump-with-WIFI.product.100409862.html
.
HD had that same brand and size unit for $825. But it states it should be installed by a trained HVAC. And its 17.7 SEER.
https://www.homedepot.com/p/MRCOOL-...at-Pump-230-Volt-60-Hz-A-18-HP-230A/300456052
 
9 to 12000 seems to be the sweet spot for higher SEER ratings. For some reason.
 
Considering that the Home Depot authorized installer wanted about $2,000 over equipment cost to install a dealer supplied Mitsubishi five years ago I hope they have changed the business model .
 
For the Multi head unit I got Daikin. 24k compressor running three 9k heads.

For the basement MIL apartment a single 9k Fujitsu Halcyon.

I got 2 Daikin 12k heads installed in November. My guy swore up and down that each having its own outside unit (2 completely separate systems) was a better way to go than 2 heads on one outside unit. He's good so I just went with his flow, but made me wonder.
 
Another night in the 20s. I logged 55 additional kwhs over 24 hours by running resistance heat instead of wood heat. That again checks out to under 8000 btu per hour! I guess my insulation is pretty good when keeping the house just under 70. So 5.50$ in extra energy costs per day of electric resistance heat which is not as high as I would have thought.

If the minisplit cost 5000$ to install and cuts my resistance heat consumption by 66% (assuming a COP of 3), then I would only have paid 1.82$ so a savings of 3.68$ per day of use. It would take 1,358 winter days of use to cover the installation cost. If I was a non-woodburner and needed to heat on average 180 days per year then the thing would have a 7.5 year break even point. That's not bad if wood heat was flat out banned forever. The equipment should last 10 years. I made an assumption above of 180 days of heat but we really need less heat for a longer time in the shoulder seasons. I also believe that the COP of 3 is rather optimistic when it is below freezing but pretty close on average.

That last 2.5 years for free only adds up to a reward of 662 bucks. Will I even live here for 10 years? Will it even last for 10 years? Will there be a better technology in 10 years?

Since I do heat with wood. The only benefit is the 7 days a year or so that burning is banned where the savings would be 25.76$ per year. It would take 194 years to break even.

I am not going to install the minisplit. They are just too expensive to make financial sense in my situation due to small heating load and cheap power. Resistance heat for the win!

Just thought I would touch base here again. Been extremely busy lately and running out of dry wood I just flipped the breakers back on for the baseboards early February. Boy I wish my house was only $5.50 a day extra to heat with those. With maybe 2 1/2-3 weeks running on this billing cycle I used approximately 153% more energy than last year this time. So $160 more than last month. While it equals out to about $5.30 a day I didn’t have them on the whole month and I’m not entirely sure when I turned them on though so it still may be close to $5.50 a day the whole month having $250 plus electric bills is not entirely fun. I have a feeling though for me it will be between $8-11 a day.

So in reality I just need to work harder at getting ahead on wood. That bill is definitely motivating for that.


Lopi Rockport
Blaze King Ashford 25
 
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I got 2 Daikin 12k heads installed in November. My guy swore up and down that each having its own outside unit (2 completely separate systems) was a better way to go than 2 heads on one outside unit. He's good so I just went with his flow, but made me wonder.

What I do know about having two compressors is one head cannot “disable” the other by being in a different mode.
I suppose you have a redundant system with your installation. Are the compressors next to one another? Maybe he didn’t want to run extra line hide?

I had originally planned on doing all four off of one compressor. After some discussion we decided to put the apartment on its own system. That way whatever random Airbnb guest is staying their cannot inadvertently disable the units in my living area.
They had the Fujitsu at the shop so I went for it.
 
On a single polar vortex day, with the split HP running with backup strips....I will use 200 kWh in one day. $30 from a local wind farm, delivered.
 
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On a single polar vortex day, with the split HP running with backup strips....I will use 200 kWh in one day. $30 from a local wind farm, delivered.

True”dat. Our electric bills go up a few hundred dollars in any month we get just a few days of teens or single-digit temps, ever since we installed the mini-splits. I’m only using them to keep two outbuildings up to 55F, but they can still suck an amazing amount of energy, when it gets real cold outside.
 
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I think that NA is a bad market for those. We have all these high-temp passive hydronic radiators, and the HP can't lift hot enough to run them. I thought the air to water systems were low temp, with a blower required for going back to heating air...

Does anyone know?