Hello. I'll give some background on my home. Its about 1000sq ft in south west pa. The ceiling has around r50 or so in the attic, walls are r13 plus I added some foam board when I added vinyl siding. The foam board ranges in thickness on each side of the house due to how far windows hang out. Living room has a r5, bedrooms around a r1 and the dining room side around a r2.5 and got a mud room attached to the living room/kitchen side and then the garage beside that. Windows are replacment bow in the living room (10ft by 3.5ft), dining room a picture window and two windows; one on each side that are replacements also and is 8ft by 3.5 ft total. All replaced in 2010. The rest of the house are smaller (2.5-3ft by 3ft- 4ft) but a few needs replaced eventually. Basement not heated in stays in the 40s. It has radiant ceiling heat and decided to heat with infrared heaters after the first year since it was pricey and it did save quite a bit since I was only heating it up when I was home and left the ceiling heat at 58-60. I was told by a friend of doing a heat pump and so I decided for a fe18na heat pump and installed it in the living room (X in the pic) It worked well this past year. I believe its too big for temps in the 50s since it short cycles but is great as it gets in the low 30s and below.I kept it set at 72 with the fan on it on high speed setting and The rest of the house was 4 to 5 degrees or so colder until it was in the teens and below it would drop to 63 and then to 60 below 10 degrees with the ceiling heat holding temp there. My bedroom I used a floor fan in the door way facing toward the living room to circulate warm air into the bedroom but in around 5 degrees the it would get chilly in there. I thinking of adding at least another unit and was thinking of a fugitsu floor mount (9rlffh) in the living room on the opposite wall of the kitchen to push heat out there. I was debating another one for one of the bedrooms but don't know its worth it. Any suggestions are welcome. Thanks

I forgot to add kw usage for a rough idea. The lady before me pulled in 4800 kw in the coldest month and last year I was down to 1202 for the coldest month of average temp of 23. Also I made an estimate chart for the celing heat for each room and figured it was around 47000btus though Idk if its even close.

It doesn't want to upload my image.

My suggestion is to have an energy audit done and pay particular attention to the blower door test. Find the air leaks in your house and go after them vigorously. Wouldn't be at all surprised if you can drastically improve the comfort in your house by sealing the leaks that are allowing all the heat you are making to escape outside. Keep it in the house!

Listen to Bob- he's definitely on the right track regarding your house with the information you've shared.

In SW PA the deep subsoil temps are in the low 50s:




If your basement stagnates in the 40s and not the high-50s when the rooms above are averaging 65-70F it's an indication that your basement is probably completely uninsulated, and likely leaking copious air at the foundation sills. 

Given the insulation levels of the rest of your house, even if you have only 18-24" of exposed foundation the foundation losses are probably 1/4 or more of the total heat loss.  A tight IRC 2012 code-min 1000' house with a full basement would have a design heat load of less than 20,000 BTU/hr, or even under 15K (and well within the output of the FE18 @ +5F) at your likely 99% outside design temp in the positive single digits F.

Most of your  house sounds like it's up to IRC 2012 levels of insulation. IRC 2012 code-min R for foundations in your US climate zone 5A is R15 continuous, which is best done with either 3" of foil-faced polyisocyanurate foam, or 1" of foam trapped to the foundation with a 2x4 studwall insulated with unfaced or kraft-faced batts (and not R19 batts in 2x6 framing, which would work thermally, but would be a mold hazard.)




You can probably air-seal the house and insulate the foundation for the installed cost of another mini-split. The basement would be warmer AND drier,  the house would be more comfortable, and the total energy use would be much lower.

If you didn't already have the FE18, insulating & air sealing would put your load with range of the Fujistu -18RLFCD mini-ducted unit, which runs at comparable to (or even slightly higher efficiency than) the FE18, which would solve the temperature difference issues.  If you decide to add another mini-split anyway (not recommended, but if...) A mini-ducted 3/4 ton Fujitsu -9RLFCD mounted at the basement ceiling, ducted only to the rooms doored-off from the zone covered by the FE18 would be about right.

Thanks for all the info. The basement has insulation but it's probably not in good condition from all the moisture. Half The basement walls do have insulation. The rafters all have insulation also and probably in a little better shape. The Windows do need updated. If insulated the foundation would that raise the Radeon levels? Also my one wall in the basement collects moisture in the walls when it's really rainy out.

Would that that much of an effect on the heating area of the house subs keep the rooms in the low 60s to near 70? Also having two big windows don't help when it's cold. The house has always been cold since I bought it. The air conditioning is fine for what I need. It's using 300 -500 watts for cooling on 90 degrees days with the room being 71.

Would that unit work lower then -5? I wanted something so I don't have to use the ceiling heat.

Would that unit work lower then -5? I wanted something so I don't have to use the ceiling heat.

please describe your basement insulation in detail

The ceilings in the basement are insulated with a roll r13. The joists do need done though. I believe half the walls are insulated The same since they have wood panel on but not totally sure. If they are the moisture probably destroyed it.

Fiberglass insulation has no place in a damp basement!

Basement conditioning that should be done:
1. Closed cell spray foam at the sill/rim joist area.

2. The basement exterior foundation walls should be insulated (on the inside) with foam sheets or closed cell spray foam; minimum 2". If it is left exposed to the interior, the foam must be "fire rated" or covered with a fire rated paint. Ideal foam to use is foil faced polyisocyanurate (the yellowish foam)

3. Ideally you would install a heavy plastic on the concrete floor with sheet foam (EPS) above and concrete above that. The foam on the walls and the plastic on the floor will help keep the basement - and the house - drier.

The first thing to do is air sealing - so the sill/rim area needs to be addressed first. (This will probably show up on the energy audit.) The air that comes in here is drawn out of the house higher up - at your roof/attic area, which will also need to be addressed.

An insulated basement will basically stay the temperature of the ground under the house (55o +/-). An air sealed basement will be free of drafts. And you can eliminate the insulation on the basement ceiling.

The Fujitsu xxRLFCD units keep chugging away no matter how cold it gets, even though the lowest temp at which the specify the exact output is -5F. At -15F they'll still be going and putting out a lot of heat, but not quite as much as at -5F, and at lower efficiency. The lowest specified output for the FE18 is at -13F, but they'll keep going at least as low as -18F (though there is some lower temp at which the Mitsubishi does an auto-shutdown, and won't auto-start again until it warms up to -13F.)

What Bob said about the basement insulation (almost). If you're going to finish the basement you can safely get to code-min performance with R5 foam (more foam than R5 is better) trapped to the foundation with a 2x4 studwall with unfaced R15 batts and no interior vapor retarders (kraft R13s would be OK, but not foil-faced.) Tape the seams of the foam with the appropriate tape, and seal the wall-foam to the foundation sill foam with can-foam or more closed cell goods. Install wallboard on the interior as an air-barrier & ignition/thermal barrier for the foam.

To get to code-min with polyiso-only would take 2.5" or thicker continuous foam, and with EPS it would take 4". With polyiso it's thin enough that you can trap it to the foundation walls with furring secured with masory screws through-screwed to the foundation. With 4" EPS that's a pretty long (and hard to find) masonry screw, but still do-able. You can then hang wallboard or paneling on the furring for a finished basement. You wouldn't need to use a fire-rated foam if using wallboard.

For the DIYer 1-2" of foam trapped to the wall with a studwall is easier. Even though R5 foam would be the minimum necessary for wintertime dew point control for R13-R15 batts, R8+ (2" of EPS, or 1.5" of polyiso) would be better. That way summer or winter, the temperature of the wood and the fiber insulation all stays sufficiently above the dew point temp of the basement air to stay out of the mold-growth humidity levels.

With foil faced polyiso wall foam you need to keep the cut edge off the slab or it'll wick moisture. With a studwall you also want to insulate under the bottom plate and provide a capillary break there too. An inch of EPS under the bottom plate that extends all the way to the foundation wall concrete would do the trick.

If using closed cell spray foam on the foundation wall and leaving it unfinished you would need to paint it with an intumescent paint to reduce the fire hazard. Since close cell foam is expensive for it's R-value and must be installed at lifts of no more than 2" (to avoid shrinkage or fire hazard as it cures), the practical/financial limit is really 2", even though that doesn't quite meet the R15 code-min performance level.

Demolishing the slab and adding slab foam insulation may not be cost effective on energy use (it is in new construction) but it would improve the moisture situation in the basement by quite a bit.

You can't really properly air-seal the basement walls and foundation sills with the paneled stuff in place. If the studs aren't moldy or rotting you can probably re-use the lumber for a foam+ studwall approach. In most cases foundation studwalls with batts built tight to the foundation the batts will have wicked enough moisture from the concrete to cause mold conditions in the kraft facers or paneling in several places, if not the whole thing, but often the studs will have survived. In winter they might even have frost crystals growing in the above-grade fiberglass at times, undercutting performance significantly. The fact that the basement stagnates in the 40s in winter indicates that the thermal performance of whatever is there is quite poor. It should never drop below 55F in there if it's air-tight and the wall insulation is up to snuff.

If the R13s between the basement ceiling joists aren't moldy or full of rat-poop you can just leave them (or use them in your wall stack-up), but it won't change the thermal performance of the house after you've properly insulated the walls. You'll probably have to pull a bunch of it down if you're installing a ducted mini-split in the basement.

If you ARE going for the ducted mini-split, there's little to no down side to oversizing those units, since the minimum-modulated output of the 18RLFCD is the same as the 9RLFCD. The ducts need to be a bit bigger, and the up-front cost of the unit is few hundred more, but the 18 is probably big enough to heat your whole house (without the Mitsubishi you already have.) The "right" thing to do would be to carefully calculate the room-by-room heat loads to be able to size the ducts correcty, and size the mini-split correctly. Oversizing a mini-split improves efficiency somewhat, but becomes a comfort & noise problem at the higher air flows, or if it's cycling on/off instead of modulating.

Thanks for all the info. A lot will need down there and lots of expenses. I'd have to do a little at a time. The thing I'm worried is about Radeon levels goin up with the insulating.
I'm still thinking a mini spit would still be needed from all the windows and getting it up to 70 all winter in the whole house. I wanted to to the install except vacuuming the lines but is it possible for me to do a ducted line myself? Also the ducts would have to run 25 to 35 ft. If not it would have to be ductless though the problem is getting heat from one side of the house to the opposite side . I was using the box fan for that. I had a drawing of the floor plan but it won't load to show the set-up.

I did my own manual j last year. I did it for 0 outside and 60 inside. I knew the fena18 couldn't handle the whole load If the house was set warmer. One of the heating companies that I had out to get a feel said I'd need more then one while another said the unit wouldn't work at all.

A leaky house house will keep radon levels down, but radon gas can be sealed off from your house & vented out. Before you insulate the floor, cut a 4"+ hole through the floor for a 4" radon vent pipe, insulate around it and tape the insulation to the pipe with 3M8067 or Siga Wigluv (expensive but worth it). Tape the insulation seams, and tape the plastic on top of the insulation. SIGA also makes tape that sticks to concrete. Run a pipe up through the new floor & vent it out, install an inline fan if necessary.

Tighten the place up, THEN worry about the radon problem (and measure it, don't assume!) Just 'cuz the basement leaks air like a sieve doesn't mean it has a guaranteed infiltration rate big enough to manage the radon levels, and random air leakage is a much bigger heat loss than heat recovery ventilation- ventilation that could be putting and purging the air from the most appropriate places.

A small heat recovery ventilator (like the simple to install ductless Lunos system) would be cheaper to install & operate than a full-on slab depressurization fan approach to radon remediation, and would almost certainly be big enough to manage the radon load of a 1000' basement. It's about $1KUSD per pair, is fairly DIY-able, has very high heat recovery efficiency, and less than 5 watts of continuous load per pair. Even the smallest slab depressurizaion fans are 20 watts, and can drive air infiltration, with the incoming air of unknown source/path/air-quality.

A quickie video primer on how the Lunos HRV works:

https://www.youtube.com/watch?v=oVYTWxv0Wok

You basically install one through the band-joist on one end of the basement (and insulate/air seal around it), and the other unit at the other end of the basement. Clean the filters every few months and it'll be fine. It's no more difficult than making a couple of holes for dryer vents, etc.

But you may not even need it- measure the radon levels first.

Installing an HRV in the living spaces can be worthwhile if you make the place super-tight, but again, you can cross that bridge if/when you come to it. (A house that tight would be a GOOD problem to have, compared to problem the house in it's current condition.)

Those definitely something that be very useful in the basement. It would get some fresh air in there. Would you need heat down there in the winter?

I stopped by home depot tonight and wanted to see if they had ductwork if I bought the unit. How long can the ductwork run? I've been trying to find some info but no luck on there site.

The Fujitsu mini-duct units have pretty decent push, and the ducts can be pretty long if they are sufficiently straight and of adequate size. They publish the curves for cfm at different static pressures (which is determined by the duct design, and how dirty the air filter is) and blower speeds in the submittal pages, eg:

http://www.fujitsugeneral.com/PDF_06/Submittals/18RLFCD%20Submittal.pdf

It's better if you either study up on duct design first, or have a competent pro design it for the unit you intend to use. When in doubt, oversize it a bit. You may want to use the insulated basement as a return plenum to simplify the design, rather than installing return ducts, and do a "home run" approach for the supply duct to a short fat supply plenum right at the air handler, with a few balancing vanes to tweak the room to room temperature balance.

The shorter the supply ducts, the lower the pressure, and the higher the average efficiency. Even though it's traditional to install the supply registers under windows, with decent windows there is no longer much point to that approach. With a 1000' house with the cassette located somewhere in the middle I cant imagine any of the duct runs would need to be more than 20' away even IF they were installed under windows. If using door cuts or jump ducts to a common return in the hall or something, as long as the supply duct is on the far end of the room from the return path it'll have reasonable room air exchange without short-circuiting the flow, then it's just a matter of supplying the necessary flow volumes.

Hard-piped ducts impart far less pressure than flex ducts, and if you size them proportionally to the different heat loads of the rooms you won't go too wrong even if you're "just hacking" rather than designing the duct system per ACCA Manual-D standards.

Quite a few mini-split installers "...don't do ducts..."- they don't have the necessary tools or design experience to get it right and would rather not get involved, so you may have to get the ducts designed by a third party, basing it on your room by room load calculations and the specs for the mini-duct cassette.

With or without the ERV you don't need to actively heat the basement, but if you're using the basement as a return plenum for a mini-ducted unit it would be somewhat passively heated by the cool return air. That would also guarantee that air won't stagnate in an air-tight basement, and the HRV could be installed elsewhere if you wanted to (though it's probably easiest in the basement.

Dana, Thanks for the info since I haven't found much of any use on this subject. I keep trying to upload a layout so theres an image to look at but it won't upload. I could pm the layout if that would give an idea. I haven't found much on the duct sizing on length or diameter. I found pictures but there crazy designs. I'm thinking of something simple. I could a straight duct for less but limits to where I could heat due to running the drain pipe. If I took the house and cut it in long ways and say one half is top and the other is half bottom. I would want to mount the unit in the basement on the "top half in the center of it and run duct out and then have a split there to go left and another right to cover both sections. Trying to center it between the two would end up 12 ft each right and 12 ft left The right duct could do the kitchen and dining room, The left is the one with a little more extra ductwork. If it was possible would be to do a 90 degree turn for so I could use it for another 4 to 8 ft ( depending where the exact mount is in the basement) to hit both bedrooms with a Y duct. I'm just thinking it might not have enough cfm to carry that far. The return vents would probaley have to be split in the dining room and in the closest bedroom into the the unit in the basement if possible. Does this sound doable or just too much area to cover? You said about doing a return in the basement but I would need a vent to heat down there if I was doing that wouldn't I or would it draw the air from the rooms above? I know I forgot to include this but the rooms are within 30 sq ft in size and all stayed close to the the same temperature during heating in the winter.

It's best to not separate supply and return registers - ie, make sure there is nothing (same room) or an open door between them. Vents can work, but often create significant pressure differentials which are bad for in/ex filtration and wall/ceiling moisture. I'd calculate and measure it and keep it less than 1 pascal (and even that is likely to double ACH_nat that you work so hard to reduce).