The best way to address cold weather comfort is to recognize the significance or MRT. You can cover the window, especially at night, but you must raise one service or another to get comfortable. Yours frankly, is a no-brainer, having lived on radiant floors since 1990 I can tell you that it redefines comfort.

In the short term I would radiate the floor with plates and use a condensing propane water heater to heat both. You should cover the crawl space floor regardless, but closing encapsulating the crawl space the crawl space.

Put the heat where you need it. At your feet.

"5835 CFM/50 is a veritable wind tunnel"
If my very rough calcs are any indication (ACH=60*CFM/Volume) and you have a volume of 4000x8.5' = 60*(5835)/34000) your ACH number is around 10, which is, frankly AWFUL. No wonder you are cold! Stop looking at expensive systems and other stuff and FIX YOUR AIR LEAKS!!!!! Sure, you have lots of ventilation, (i.e.: fresh air) but at 10 air changes per hour, it's no wonder the house is uncomfortable. Typical places are between the slab and the wall; any place there is a light or other opening into the attic; around doors and windows (under the trim), but the easiest way to find them is with a blower door and IR camera or fog machine. Most of this will be time & a few tubes of caulk and foam.

"Stop looking at expensive systems and other stuff and FIX YOUR AIR LEAKS!!!!!"

Seriously!

Unless of course you're trying to heat and air condition the whole damned county (which you kinda are!) :-)

It might be hard to fix all of the leakage related to the ducts being in the attic without some heroic measures, but it's worth a shot. A duct-blaster test is also in order, to verify that you're not driving air infiltration with the air handler too. CA Title 24 has pretty good standards for duct leakage- if you can't meet that standard you MUST bring the ducts inside the pressure & thermal boundary of the house to have reasonable system efficiency.

We install Unico system with duct work in the attic regularly. In fact I am installing one in my own house next week.

Once all the ductwork, extremely tight unico, is in place two feet puts it--in the conditioned space--. It don't care who you are.

I would go for another blower door with remediation and love exterior thermal storms. The just make sense.

Still, when you get done and can't take your sweater off, remember me.

This conversation is almost fun. If only it wouldn't end in massive spending!

OK, so Bob l, our ceiling height averages about 11'. That brings the wind tunnel down to a mere 7.95. :-) To tighten that up, we don't have a slab, the exterior is all stucco, and the interior has tight-fitting baseboards. All the windows are super tight, and have no trim/casing around them. There are two expected culprits. 1) The ceiling/attic, which also has inadequate R13 insulation. The bid to seal and replace with R49 is $20K, and since we have ~40% possibly uninsulated vaulted ceilings and all that glass, I wonder how smart that spend is relative to solar + ASHPs to "BTU my way out of it." 2) French doors (also no casing), which are impossible to get to seal completely. Even finding the right weatherstriping has been a trial and error mission through internet-based suppliers (no one carries anything locally).

The ducts are tight (shocking!), <6% leakage (I erred before on the %). We can't build a platform over them, and we can't move them to the crawlspace (there's nowhere to get them down there from the attic unless we find a spot to sneak them down in a chute). They only have R4 insulation around them. I don't get why the standard isn't some kind of R13 blanket.

Dana...

"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."

We hit the 41c, just barely. Any marginal use for us is at that level. Thus, solar. If I had excess solar-generated electricity, we would run a lot more lights, too.

"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."

I understand. The only window option we have is to rebuild the sashes as dual pane. Storms may make sense on paper. Here, even aesthetics aside, we open our windows all year long. For example, Weds was 78F here, and we enjoyed the free warmth. Plus, we have a very large arched window that wouldn't work, a mostly-glass front door, and 6 sets of double french doors. One question I have is how much dual panes really help. We have a few duals, where the previous owner had to replace singles and probably couldn't get look-a-like wood singles anymore at reasonable cost. My infrared reads the duals maybe 1F warmer than the singles (room air 65F, dual window 55F, single 54F).

From my Manual 'J' modeling I can say without hesitation than doubling R-13 where you can makes sense. If this covers some of that super-tight duct work, mores the better.

We work on many turn-of-the-century homes here in Minneapolis, some without any insulation, and all with some form of hydronic heating. Many come to us after an extensive kitchen remodel-where everything but the new Sub-Zero and Viking stove goes out the new full view back door; including the only radiator!

We radiate walls, ceilings and floors until they get that old time radiant feeling back. There is no substitute for MRT.

From my Manual 'J' modeling I can say without hesitation than doubling R-13 where you can makes sense. If this covers some of that super-tight duct work, mores the better.

We work on many turn-of-the-century homes here in Minneapolis, some without any insulation, and all with some form of hydronic heating. Many come to us after an extensive kitchen remodel-where everything but the new Sub-Zero and Viking stove goes out the new full view back door; including the only radiator!

We radiate walls, ceilings and floors until they get that old time radiant feeling back. There is no substitute for MRT.

From my Manual 'J' modeling I can say without hesitation than doubling R-13 where you can makes sense. If this covers some of that super-tight duct work, mores the better.

We work on many turn-of-the-century homes here in Minneapolis, some without any insulation, and all with some form of hydronic heating. Many come to us after an extensive kitchen remodel-where everything but the new Sub-Zero and Viking stove goes out the new full view back door; including the only radiator!

We radiate walls, ceilings and floors until they get that old time radiant feeling back. There is no substitute for MRT.

The bid to seal and replace with R49 is $20K

While that might be ideal, just blowing cellulose up there might have a better ROI (it's what I did - no noticeable drafts).

Yes. Blow a foot over what you have and call it good.

Minneapolis with no insulation!? I'm complaining about 45F temps outside with at least some insulation. Yikes.

If tents are tighter than our house, wouldn't attic sealing be mission critical, before a pile of cellulose? We're planning a possible remodel (to fix another ridiculous decision the previous owner made) that would open up some of the ceiling.

BadgerBMN, I love the sound of radiant. It's the $100k and then burning propane (or storing hot solar water) to do it that's the issue. Could I do it with electric, and a 10kw array, or would that not be enough juice to offset it (figuring 40kw/day generation on average per day)?

BTW, one proposal included sweet recycled denim insulation. Looks awesome. Oh yeah, and $30k.

AztecSD: you are missing the point. Whenever I mention air sealing, people start talking about insulation. They are not the same things and one does not replace the other. You could replace your R13 insulation with R100, but if you do not repair your air leaks, you will still be cold. You cannot guess where the air leaks are are or where they are not, you must use diagnostic tools, and you must reduce your infiltration.

You're finding lots of problems but I'm not sure anyone here can tell you where to start. Put on your deerslayer hat for a minute. Periodic episodes corresponding with cold spells or continuous discomfort? Bad on blustery days vs calm? Cold spots in the house? Near windows? Exterior walls? Slab or crawl space? Does the colf linger through the day? (Glass warms quickly; masonry doesn't.) Feel free to slap a thermometer on surfaces. If your neighbors have houses from the same era, how do they fare and what issues have they fixed?

Could be the occasional shiver is part of your future. If your walls are cement block filled with concrete and covered with stucco, it's not done just for earthquakes. Mass that averages out diurnal swings in temperature will be welcome in the summer -- indeed, most of the year in the desert southwest. Indians built kivas -- high-mass fireplaces -- to handle the occasional cold spell. If mass is your root problem, the answer is a relatively inexpensive source of major btus to be fired as necessary.

That isn't to say that air sealing and insulating aren't worthwhile. Consider thermal window treatments if glass is the problem. But don't spend megabucks until you understand hvac in Rancho Santa Fe.

Posted By Bob I on 05 Dec 2015 08:50 AM
AztecSD: you are missing the point. Whenever I mention air sealing, people start talking about insulation. They are not the same things and one does not replace the other. You could replace your R13 insulation with R100, but if you do not repair your air leaks, you will still be cold. You cannot guess where the air leaks are are or where they are not, you must use diagnostic tools, and you must reduce your infiltration.

No, I understand the point. I was saying that just adding cellulose on top without sealing first seemed suboptimal, even if it does add about $10k to the work.

Posted By toddm on 05 Dec 2015 10:06 AM
You're finding lots of problems but I'm not sure anyone here can tell you where to start. Put on your deerslayer hat for a minute. Periodic episodes corresponding with cold spells or continuous discomfort? Bad on blustery days vs calm? Cold spots in the house? Near windows? Exterior walls? Slab or crawl space? Does the colf linger through the day? (Glass warms quickly; masonry doesn't.) Feel free to slap a thermometer on surfaces. If your neighbors have houses from the same era, how do they fare and what issues have they fixed?

Could be the occasional shiver is part of your future. If your walls are cement block filled with concrete and covered with stucco, it's not done just for earthquakes. Mass that averages out diurnal swings in temperature will be welcome in the summer -- indeed, most of the year in the desert southwest. Indians built kivas -- high-mass fireplaces -- to handle the occasional cold spell. If mass is your root problem, the answer is a relatively inexpensive source of major btus to be fired as necessary.

That isn't to say that air sealing and insulating aren't worthwhile. Consider thermal window treatments if glass is the problem. But don't spend megabucks until you understand hvac in Rancho Santa Fe.

I think everything BUT mass is the problem. Lots of glass, single pane, R-7 (guessing) walls, R-13 ceiling with some vaulted ceilings having zero or maybe 2" of rigid foam, skylights, somewhat leaky, built over a ventilated subterranean crawlspace. The only fixable things are improved attic sealing and insulation in non-vaulted areas, sealing the crawlspace. We could potentially shoot foam into some of the walls. As for neighbors, I've discussed it, and everyone mostly just solves it with lots of propane-driven conventional FAUs. They apparently don't mind spending >$1000/mo on propane for 5 months of the year. I do!

Did I understand you correctly; this is a wood frame house right? Not concrete filled block?

Look at the big picture; you're living in a semi-arid climate in a leaky wood frame house with little insulation and no mass or earth coupling. Such a house will gladly cool off quickly after the hot summer sun goes down, but it's going to leave you shivering in the mild winter. Throw BTUs at it all you want, but it's going to cool off as soon as the BTUs are turned off.

Posted By Jelly on 05 Dec 2015 02:03 PM
Did I understand you correctly; this is a wood frame house right? Not concrete filled block?

Look at the big picture; you're living in a semi-arid climate in a leaky wood frame house with little insulation and no mass or earth coupling. Such a house will gladly cool off quickly after the hot summer sun goes down, but it's going to leave you shivering in the mild winter. Throw BTUs at it all you want, but it's going to cool off as soon as the BTUs are turned off.

Yes, exactly. Which is why I want to stop the leaking as much as I can (worth $10k?), insulate as much as I can ($15k) in the areas we can. And then secure a cheap source of BTUs (solar ASHP or ???). Just trying to figure out the most efficient spend, and how much is enough.

How is the solar orientation? Any large south-facing windows? A passive house designer couldn't ask for better conditions than SD county. If you could control the leaks and insulation then you may not even need the significant source of BTUs.

Posted By Jelly on 05 Dec 2015 03:32 PM
How is the solar orientation? Any large south-facing windows? A passive house designer couldn't ask for better conditions than SD county. If you could control the leaks and insulation then you may not even need the significant source of BTUs.

House is long, with main living areas facing approx southeast. Doesn't lay out well for solar gain after 9am in the winter. A solar array fits well with the roof, though, and we can get 7kwh, as much as 10kwh if we put some everywhere possible (a separate structure's roof).