Great forum -- good reading. Apologies that this first post is lengthy. Our house is in north county San Diego, about 5 miles inland. You (read: I) would think that our insulation/heating needs would be minimal. And yet, when day temps fail to exceed 75F and/or the night lows drop below 55F, this house FREEZES. Even when we heat the place to >68F, it feels like a window is open (however there is no detectable draft). Overnight, inside we'll go from 64F down to 60F. We get about +2F of solar gain in the winter. Summer we have no problem with heat, with the house easily staying <80F unless a lengthy >90F wave hits. FACTS: - Built in 1990, remodeled by previous owner in 2005. - We're on propane, two FAUs in the attic, for 4000 sq ft. At nearly $4/gallon, we're loathe to run them. Grilles have what appear to be somewhat restrictive decorative designs. - Three rooms have vaulted ceilings with beams/t&g that appear to have only minimal insulation between that and the tile roof. Some skylights in them as well. - Ceilings range from 9' to 12' peaks in some vaulted areas. - Single pane (laminated) wood windows and doors, with a "normal" amount of glass. - Built over a 2' crawlspace that is vented, floor is insulated. - Walls are min 2x6, some areas double wall (no clue whether they bothered to double insulate!). - We had a blower test, and scored in the "normal" range for a house of its size. The ducts were very tight, at less than 3% leakage (the testers were very surprised). - Energy auditor found poorly sealed attic areas that are open to a few small walls below. Insulation is R30, but a few areas are poorly laid out. - I have hit all the walls with an infrared thermo, and pretty much everything is cold. I can find no single culprit, including the aforementioned cold walls. Even the attic access (just drywall piece) is maybe only a degree or two colder than everywhere else. As you can see, we are the model of inefficiency. I grossly underestimated the heating needs when considering the house. The question is what to do. *Everything* is expensive. We can't do much of anything about the vaulted ceiling insulation. there's no room to add more than maybe 1" to the underside. Bids for removing the attic insulation, sealing, and then properly re-insulating have run $25K+. Changing the windows/doors to high efficiency would be at least $200k (thanks, partially, to stucco walls that would all have to be done over). I CAN have just the sashes/doors rebuilt as dual pane, using a custom shop, around $100k. I've considered simply throwing massive BTUs at the problem, which I could do with solar + air source heat pump (mini duct/ductless in a few key areas). Ah, but >$50k, and I'd live/die by net metering given our heat needs are greatest when sun is weakest. Radiant? Solar + electric under subfloor radiant for at least our primary living areas. Well above $60k. And it would still leave us with other cold areas. I'm sure I've left out some stuff. I'm curious what ideas others have. Thanks.

A couple of mini-splits will be a lot less than $50K and be cheaper to run than propane or electric radiant. A good energy audit should have covered the best options and prices. And a list of where the heat is going.

The $50k is including $30k of solar to run them. Our electricity is among the most expensive in the country at .43/kilowatt, so ASHPs are a lot more expensive to run than in most areas. As for the equipment itself, each mini here runs about $7k for standard install. Because of the aesthetics, we'd have to get clever with ducting to hide them (the house is old Spanish style).

The energy audit I got wasn't that sophisticated. Mostly involved a visual inspection (described above) and the blower test. Beyond that, their recommendations were to do the insulation work first to see if/how much it helps. Way too expensive for something that is effectively just a test! I think they were "talking their book" because they do that kind of work.

I went back and reviewed the audit. Actually, I was wrong, they provided a detailed calculation per room. But I don't put any stock in it, given the assumptions they had to make. For example, their recommendations call for R49 in all ceilings. That's impossible in >50% of the house, thanks to the vaulted ceilings.

Is the house slab on grade? Are the soils damp under the house? What are the floor coverings?

You might also look at an automated whole house fan so that when outdoor temperatures are favorable, the outside air is efficiently used to heat/cool your home's thermal mass.

FBBP -- 90% of the house is over a ventilated crawl space. The remainder is on slab (additions from 2005). I can detect no difference in temps between the two areas. Floor is wood everywhere except closets and one small bedroom.

JONR -- I like that. Currently, when we know outside air temp = inside air, we open windows and doors. Today we raised from 64F to 68F that way. I went around with the infrared when I closed everything back up. It was still 68F, and pretty much all the walls, floors, window glass, everything, were around 62-64F. And yet it felt really cold, much colder than 68F. The wife had blue fingers!

True, what you feel is a combination of the air temp and the surrounding surfaces (mean radiant temp). But keep the interior at 68F for awhile and in your mild climate, the surfaces should get close to that.

If nobody has used a thermal camera (vs single point gun) on your house, the "Seek Thermal Imager" looks interesting.

Makes sense.

Thermo says 68F now, walls are 64-66F, and windows are 58-59F. Feels very cold, with us in sweatshirts, etc. Not even close to comfy. It took the heater about an hour to raise it from 67 up to 69F.

On the window front, explore the possibility of replacing just the single pane glass with just a Insulated Glass Unit (IGU). Will depend on how the original windows are built, but if you can just replace the pane with an IGU without having to bugger up the stucco and the original frames the cost will come down appreciably. You will also be able to order IGU's with the coatings most beneficial to your goals and window orientations.

Low E storm windows mounted to the original window frames is a heluva lot cheaper than replacement windows or replacement sashes, and installed over wood-sash single panes they deliver comparable performance to a code-min replacement window. The Larson low-E storms sold through box-stores are fine as long as you upgrade to the Silver or Gold series, which are much tighter than their bottom-priced Bronze series.

In your area a ventilated crawlspace works from a moisture point of view, but thermally you'd be better off with a ground-vapor barrier and sealed crawlspace, which lowers infiltration, and couples the house to the thermal mass of the soil, which is at a favorable temperature, very near conditioned space temperatures.

The notion that you need $20K of mini-split to heat and cool this place seems way overpriced. A 1.5 ton ducted Fujitsu would be less than half that (ducts included if you have space to run them), and probably cover the loads of most homes in San Diego county. Get an and independent Manual-J heat load calculation using aggressive assumptions on the "after" picture of any envelope upgrades before choosing the equipment. Even if you keep it warmer than 68F indoors or cooler than 76F, use only those for the heating & cooling load calculations, and only the 99% and 1% outside design temperatures. You can heat /cool the house to any temperature you like, but if you start out with anything beyond that you risk oversizing the equipment to the point of operating less efficiently, at a a higher upfront price tag too.

Also 43 cents/kwh? Really? That's what it costs for diesel fired isolated island power! If you're on the CAISO grid it's probably not that high until you're at the third tier of the rate structure, which you might hit if heating with resistance electricity, but probably not if heating with decent heat pumps.

Got a ZIP code?

Sorry about the delayed reply. I was away someplace WARM, and just returned to our meat locker of a house. Our zip is 92067, Rancho Santa Fe. Re: storm windows, it would greatly clash with the aesthetics of the house. No can do. Re: replacing the glazing, we have laminated and coated glass. I don't know exactly what it is, but the custom window maker who has looked says we have about the best single panes possible (including for sound attenuation). We do have a few double panes and when I test them for temp, they are almost identical to the single panes. That makes me skeptical about the value of rebuilding all the sashes with doubles. I just did a walk around with my infrared again. Everything is about the same temp within zones of the house, even the uninsulated attic access panel. We have a few cold walls where the attic air is sneaking down into the wall, and they're the same as all the walls around. The floor is 2-4F cooler than the walls and ceiling.

Whoops, I hit submit prematurely. I had a solar guy over and he thinks we can squeeze in about 10kw array in a way that the town might allow. Obviously not cheap. And then we could run the minisplits and "just" solve the problem with boatloads of BTUs, relying heavily on net metering.

Re: the cost per kw, YEP, it's 41.7 cents on the margin. And it takes only modest usage to reach that top bracket, for us about 290kw for a month. Crazy, no?
https://www.sdge.com/sites/default/files/regulatory/11-1-15%20Schedule%20DR%20Total%20Rates%20Table.pdf

Make no mistake, when they get done shutting down all the coal plants we will all be paying a half a buck per kW for power and there will be no "cheap" or even affordable options. Precious few private homes for that matter, if we give them another 100 years to mismanage energy policy. I am investing in the thermal underwear industry.

The answer is simple. You are cold because, as Jonr suggests, the surface temperatures of your home are too low. To be exact, the mean radiant temperature is the culprit. MRT affects creature comfort more than any other single factor.

I have a associate that designed and installed radiant floor heating systems in the San Diego area for 20 years and I have designs many retrofit systems in the Bay area and others.

Dana has it half right. The crawl space is not helping. Seal it. Cover the ground with 6-mil and pull the insulation down, fasten aluminum plates up, with PEX and put the insulation back up. Once you determine the best fuel, buy a boiler that burns it. If you want hydro-solar you want a storage tank as well. Integrating DHW and radiant saves money and space. Warm floors, warm people.

Some would like us to forget why we build houses. Most of us for safety and comfort.

At 41.7 cents/kwh, I'd have lots of solar too. Preferably with net metering, but if not, then with thermal storage.

I suppose if I had a very hard to insulate/heat home, I'd look into insulating/sealing the room where I spent most of the evening time and let the other rooms be somewhat lower in temp. I'm OK with 65F for short periods or when active and 60F in a bedroom.

A mini-split heating a well sealed (to the outside, vents to the interior are fine) and insulated crawl space would solve your ducting issues and increase MRT.

Ideally, thermostats would measure MRT and air temp and control for "perceived temperature". It's not as simple as "70F". I hate sitting next to an old single pane window on a cold day. Drapes and blinds will help.

Thanks, everyone, for your thoughts. Especially the MRT issue. My wife and I tested that last night, standing in front of a window (glass temp 54F) and then a wall (wall temp 60F). HUGE difference. It's also interesting how we feel nice and warm while the FAU is blowing, and then the VERY moment it shuts off, the chill returns.

Jonr, what did you mean by "ducting issues"? Our ducts are all in the attic, if that matters.

As I continue researching this stuff, crawlspace encapsulation makes sense ($30K, though). First I have to get it relatively dry under there, and that will take rain gutters (~$25k). Thanks to the ridiculous overdone El Nino hype, I can't even get a gutter company to come out until late January!

Question: Why heat the crawlspace? Since we don't live in the space, wouldn't that be a low bang for the buck way of warming the floor? Or is the low floor temperature that critical? Right now, the air is 66F and the floor is 62-65F. In our meat locker bedroom, the air is 62F and the floor is 59F. Brrrr.

Based on our cost of propane, and our experience with DHW, radiant heat would have to be from solar (>$80k including storage).

Question: Going back to addressing low MRT, is there a difference between a boatload of ASHP heat and floor radiant? In other words, can I "solve" the problem and feel the same comfort (or close) using either method? I ask for obvious reasons -- a comprehensive solar floor radiant would be at least double the cost of solar ASHP.

Something is missing here for us to analyze your problems. For starters: "We had a blower test, and scored in the "normal" range for a house of its size."
What is "normal" range? Code around here is 7 ACH50 which is theoretically "normal", but also well within the really uncomfortable range. What exactly is your rate at ACH50?

And I'm curious what is under your MBR with the 59o floor? Crawl or slab?

You can do a rough homeowner blower door test by taping off your bedroom and using a box fan in the window (tape around the fan also), and find the air leaks. Maybe you have air leaks at the slab/wall intersections? That cold air, or cold feeling is coming from somewhere & you need to figure out where.

Jonr, what did you mean by "ducting issues"? Our ducts are all in the attic, if that matters.

This is what I was referring to:

Because of the aesthetics, we'd have to get clever with ducting to hide them (the house is old Spanish style).

I'd say that a plastic lined (floor and concrete) and foam insulated crawlspace with a dehumidifier in it wouldn't require $25K in gutters. Or require highly skilled labor.

Bob l,

The blower test says 5835 CFM at 48.6 Pa, 0.29 air changes per hour (and they recommend .35). They say it's well within the BPI Building Standard Airflow recommended levels.

jonr,

Ah, got it. I meant that we'd have to hide the heads of the mini ductless. As for the crawlspace, I was somewhat stunned by the $30k bids to do the work. Pretty simple to lay down 20mm and get it sealed tightly. I'm a hard negotiator, and yet they barely budged. We'd still need the gutters because we are getting a lot (LOT) of water under the house, making about 1500 sq ft of muddy area.

The baseline of 290 kwh to hit tier 3 is for some electricity- sipper customer, which you may be currently. Run the SDG & E baseline allowance calculator as if you were an electric heating customer with electric hot water using 1000 kwh over 30 days in January, and see where it ends up for the AVERAGE of the total bill, not just the last marginal 50kwh.

http://www.sdge.com/baseline-allowance-calculator

I'm coming up with 498 kwh for the first tier at 14 cents or whatever, and another 149 kwh for the second tier at 21 cents, with the remainder at 41 cents. At 41 cents/kwh on the high-tier margin it's financially rational to build out enough solar to cover the total bill, since the LCOE of even small time rooftop solar is half that.

Without digging into it too far, you may be better of with time of use rates (if offered) rather than the standard residential tiered rates since most of the heating load occurs during off-peak hours. Much of the cooling load occurs during on-peak, but if you added a bit of solar and limited evening use of the AC the net import from the grid during peak hours would be pretty small.

I'm not very sympathetic to folks whining about saving the aesthetics of their really great single pane windows out of one side of their mouth and comfort/utilty-cost issues out of the other. The very best single pane windows are utter crap. Interior storm windows at least double the performance, and are practically invisible. Interior storms are only a PITA for those windows that you open on a regular basis. Interior storms have improved the thermal performance of a great number of stained glass windows on historical church buildings without drawing the full ire of the historical commissions. I'm sure there's a way to improve window performance at your house too.

5835 CFM/50 is a veritable wind tunnel- there are tents tighter than that. You can probably cut that in half just fixing the big leaks, starting with sealing up the crawl space. Then there are those ducts in the attic...

Ducts in the attic above the insulation layer are an energy disaster in multiple ways, since it punches holes in the pressure boundary of the house, and puts the ducts outside of conditioned space to add to the load. Any duct or air handler leakage in the attic amplifies the infiltration rates too. If you can build out an air tight platform over the whole thing and insulate above the platform it brings it all into conditioned space, where they gain/lose less heat directly, and any nominal leakage is at least inside the pressure boundary of the house.

A mini-ducted mini-split cassette in a sealed insulated crawl space is pretty easy to hide, if you can find tolerably discrete locations for floor registers.

IRC code min for US climate zone 3 is R5 continuous insulation for crawlspace walls. That's pretty easy to do with 1" fire rated Thermax polyiso, which (in most jurisdictions wouldn't require a thermal barrier against ignition) Sealing the seams with foil tape and edges with can-foam makes it pretty air-tight. It'll need a ground vapor barrier sealed to the wall-foam, but no insulation over the dirt, which is at a nearly ideal temperature for "earth coupling" the house to the thermal mass of the soil, once you get your air leakage down to a sane level.