Mini/Multi Splits for heat

[eclecticcottage]

These came up in a topic I had posted in the boiler room about tankless water heaters as heat sources for baseboard heat. So I thought maybe a seperate topic might be in order.

The basics:
We are looking for a) central heat and AC in our Old House and b) potentially installing them in the Cottage as backup backup heat and for central AC

The Old House:
built in the 1920's
1 3/4 story (part of the ceiling upstairs is the roofline)
two bedrooms upstairs
somewhat open concept downstairs
NO basement (crawl space, not a slab)
VERY small utility room that cannot house a standard boiler
never had central heat
NG available
blown in insulation in the walls
relatively new (10 yrs?) anderson windows
@850 sq ft
No attic
currently heated with two Lopi gas stoves (Small Heritage Bay, living room and Berkshire in one bedroom)
newer (within 15 years) electric service from the pole in, with plenty of space for more breakers (it was sized to double what the house currently needs in case someone ever wanted to add on)
we lived here 15 years but have now moved to the Cottage, this will now be a rental. KISS is important given that renters will be living here

The Cottage
built in the 1950's
single story
choppy layout
originally a summer cottage, at least one wall has no insulation
the Republic is definately enough stove to heat it, and we have to run small short fires in shoulder season
Ventfree backup heat
We do plan to add more insulation in the attic at some point
no basement, most of the cottage is on a slab, the living room is an addition with concrete block foundation walls and dirt floor below, but there is insulation between the floor joists
mostly original windows with alumium storms, they aren't very leaky
two 8' sliding glass doors
originally had baseboard heat that we removed-the boiler was old and potentially not working, and the pipes were full of blown out spots from an improper winterization-we counted 20 before we stopped bothering.

We live in WNY, so both locations are subject to temps that occasionally drop to single digits. Teens do occur, but most of the time we bottom out in the 20's. The Cottage is between open fields and the lake, so it is subject to some pretty good winds (a normal day is 10-15 MPH).

We plan to leave at least the living room stove at the Old House as secondary heat, it is thermostatically controlled. We would need something in both bedrooms and the main floor downstairs, potentially the bathroom and utility room although those two rooms could also use another heat source, such as electric baseboard. the bedroom stove doesn't run long when it is on, MAYBE half an hour when it warms from 50 degrees at night and usually 15 minutes avery few hours after. the living room stove runs pretty much 24/7 once it drops to the 20's, to keep the house in the 70 degree range.

Our usage for the Cottage would be in case we want to/need to (parents who live states away getting older) go out of town for more than a day or two in heating season and we don't want to rely 100% on the VF and for AC. We still plan to heat 100% with the lopi when we are there.

Are mini/multi splits a feasable solution here? I'm more concerned with the Old House.

 

[woodgeek]

To get started, some estimate of your heating loads (BTU/hr) will be helpful. This can be weight wood/day at typical winter temps, gas usage per month and degree days, etc. The issue with mini's is whether they cover your needs, or not. A mini might be nice be nice for AC, but is unlikely (IMO) to give you cheaper BTUs that natural gas at the rental.

 

[Highbeam]

This is what the indoor part of a mini split looks like. This thing sticks out from the wall a good 8-10". Can you live with this thing bolted to a wall in either house?

What are your costs for electric and NG?

I utilize and really like the idea of the electric wall heaters in bedrooms on their own zone. Heating in the bedrooms is very customizable and optimizable with electric. Cheap too.

A single wall monster as shown in the pic is plenty for most homes. Like a stove, the heat will move and single minisplits are much less expensive than multiple systems or multiple wall monsters from a single outdoor unit.

 

[woodgeek]

I figured e-cottage would hide the indoor head behind some delightfully vintage, locally sourced cabinet.

 

[Highbeam]

I figured e-cottage would hide the indoor head behind some delightfully vintage, locally sourced cabinet.

I would love to see somebody cleverly hide one of these things as the only reason I don't have one right now is that the standard indoor unit looks like something in a ghetto hotel or a single wide. The non-standard indoor units make the system cost comparable to a ducted heat pump install.

 

[eclecticcottage]

hiding it...well...I'd have to think on that. I think it's possible.

BTU...that's going to be hard. We don't have any old gas bills around and we haven't lived there for a year. NG also ran the hot water tank. Because we have a crawl space we let the hot water run at a trickle 24/7 when temps were below 32 degrees, so that will effect the usage (we do plan on putting on heat tape so tenants won't need to do this). The Heritage Bay is a DVS which is rated at 31K BTU max. That thing will have a flame 24/7 in the winter. Except the bedroom with the door closed, it was basically trying to heat the whole house, upstairs and downstairs, from a relatively central location. I can try to sketch out the floor plan tonight if I have time.

I really wish there was another way to heat it with NG, centrally. I am looking at potential resale (if we WERE to sell it wouldn't be for at least 5-8 years) as well as rentability. Not too many people are going to be excited about using a gas stove for heat. To get our max ROI on this place, we really think we need central heat. There is NO way to run ducts. We've had contractors out to look at this. Plumbing for baseboards is a maybe, but we still don't have room for a full sized boiler (unless maybe it could hang off the joists in the crawlspace like our old gravity heater did). I guess the other option here is to use a few electric heaters to supliment the stove. The Berkshire isn't in the most ideal spot in the bedroom so we were considering removing it to give the tenant more flexability for furniture placement. The bedrooms are small, and taking a chunk out for the stove makes it even harder to make it useful. We already have closets that are basically built into the living space to make it less attractive.

BTU is hard for the Cottage too. We went through around 6-7 face cord of NOT seasoned mixed hardwood last year, plus about 60 or so packs of ecobricks. That was for the whole season, shoulder and all. Of course, that included learning the stove, and keeping it relatively warm. So far I'd say we've gone through about 2 face cord of mostly box elder that is seasoned and maybe 8 packs of ecobricks because we have them left over. The way we had the box elder stacked it's hard to tell, and we've had to move it around because of some exterior work we were doing. Next year we'll be in a good place wood wise, moving onto neatly stacked mostly pine (and some willow and maple and ???) we CSS this spring and last fall. We don't expect to use the heat feature much at the Cottage, but I'd REALLY hate to rely on the VF as a sole heat source for a week (give or take). Especially with our poor dog living there-even if the Cottage is a little leaky.

Now that I looked up the specs on the Heritage, I am thinking we might be well served to see if we can find a different stove (used) on CL with a higher BTU rating and put in some electric baseboard or wall heaters in the bedrooms, bathroom and utility room. It would still be ehhh for resale value, but still should be ok for rental. I'd like to TRY to get and keep a good long term tenant rather than looking for a new one every time the lease is up because it's cold or too expensive to heat!!

 

[Hogwildz]

Ask and ye shall receive.
These are the best looking choice I have found.
Kinda cool, and a bit better looking then the typical wall unit.
http://www.pexsupply.com/LG-LA126HN...gle-Zone-Mini-Split-Air-Conditioner-Heat-Pump

 

[begreen]

This is what the indoor part of a mini split looks like. This thing sticks out from the wall a good 8-10". Can you live with this thing bolted to a wall in either house?

What are your costs for electric and NG?

I utilize and really like the idea of the electric wall heaters in bedrooms on their own zone. Heating in the bedrooms is very customizable and optimizable with electric. Cheap too.

A single wall monster as shown in the pic is plenty for most homes. Like a stove, the heat will move and single minisplits are much less expensive than multiple systems or multiple wall monsters from a single outdoor unit.

In my eye that looks better than a glass-blackened, big black steel box that's about 8x bigger.

You might be able to put a downdraft NG, high-eff. furnace in with insulated supply ducting running in the crawlspace. Just keep the vermin out of the crawlspace.

Otherwise, there are Daikin and Mitsubishi units that should do the job.

 

[velvetfoot]

Can one install a mini split system and get a hvac contractor to charge it up? Would they do that?

 

[Highbeam]

Can one install a mini split system and get a hvac contractor to charge it up? Would they do that?

Yes. This has been done by many of the DIY types. You'll need to line up the HVAC guy before you start just to be sure. The installation is the easy part.

 

[maple1]

I really wish there was another way to heat it with NG, centrally. I am looking at potential resale (if we WERE to sell it wouldn't be for at least 5-8 years) as well as rentability. Not too many people are going to be excited about using a gas stove for heat. To get our max ROI on this place, we really think we need central heat. There is NO way to run ducts. We've had contractors out to look at this. Plumbing for baseboards is a maybe, but we still don't have room for a full sized boiler (unless maybe it could hang off the joists in the crawlspace like our old gravity heater did).

Thinking hot water baseboard and central heat - is there not such a device as a compact NG direct vent boiler?

(No NG experience here).

An electric boiler would be a very simple compact install (aside from baseboard installation issues) - but the cost to run would likely be an issue, if it was going to be used very much.

 

[velvetfoot]

Yes. This has been done by many of the DIY types. You'll need to line up the HVAC guy before you start just to be sure. The installation is the easy part.

Thanks.

 

[velvetfoot]

Thinking hot water baseboard and central heat - is there not such a device as a compact NG direct vent boiler?

(No NG experience here).

If I read correctly, I started a thread on that subject back in September: https://www.hearth.com/talk/threads/dual-purpose-instant-water-heater.89732/

 

[woodgeek]

Sooo...the old house has NG service, no way to run ducts and only a small crawlspace....I assume it has electric DHW tucked away somewhere.

Seems like you could do hydronic radiation and a compact NG fired system hung in the crawl or a closet. That would be a low operating cost, but expensive to install and not clear you would make it back on resale. Myself, I think installing hydronic baseboards all over would be a drag. Another option would be to put a water coil to air heat exchanger in 2-3 places, still have to run the piping, but the upset in the living space is potentially smaller (so perhaps the install would be cheaper?? less molding/trim work to fix?)

If you want to be cheap and run on NG, you can get 2-3 direct vent wall mount units installed and just have to run gas lines. Aesthetics be damned. But starting to look like the gas stove system you have now.

If you don't like the install cost, I would go with electric. IMO, though, that pulls down both rental and resale appeal.

For AC in your location a couple window units in the rental.

In the new house (with no NG?), sounds like you only burned 3.5-4 cord equivalent, which is not too bad for your cold climate, house vintage and possible burning learning curve. I would think a 2 ton mini would cover your AC needs easy, if you can get the coolth distributed, as well as complete shoulder season heating, and BTU help during the real winter. IF you wanted to go all 'set and forget' for heat, I think you would need/want 2 minis, and that would help with the zoning and distribution (depending on the layout we haven't seen).

Either way, you would want a pro to do a load calc, or at least you do some tracking of your wood consumption using a bathroom scale versus the outside temp. Biomass bricks are great for this....the BTUs are reliably estimatable and you just need to count them.

 

[eclecticcottage]

Old house has DHW via a "tall" 30 gallow NG heater, which is in the utility room. JUST enough room for it to fit between the wall and stacked "apartment" washer dryer. There is no other space for anything to be placed in the floor in there.

I agree sweating all the joints on baseboard heat would get old quick. After going over there yesterday we are really leaning toward electric zone heating and leaving the living room stove, but still taking out and ?? (selling? Converting to LP and putting somewhere at the Cottage?) the Berkshire from the bedroom. If we sold it, it would help defray the cost of whatever we buy to replace it. We just have to decide if we want to go with a multisplit of some sort plus a few wall heaters or all baseboard/wall heaters. *IF* we could get the multi for a good enough price, that would probably be preferable, since we can't use window units here very easily (the windows have a built in "slope" in the sill for water run off, but it makes for a pretty poor place for an AC unit!). We used the portable room ones, but they take up a lot of space both when in use and when being stored. We'd then put wall or baseboard heat in the bathroom and utility room.

The Cottage has no NG just LP. We run two 100# tanks inline for our range, DHW (tankless) and a small 10K btu blue flame in the utility area here (basically, a space about 4' x 2-3') and another single 100# for the VF.