Insulation at different latitudes

briligg · 03-24-12, 05:34 PM

As i have been struggling to calculate the amount of sun to expect at a proposed building location at about 43 deg N, finally i made a chart. I still have my reservations about its absolute accuracy, but it is as close as i can get, so i am sharing it. This is taken from the 1993 ASHRAE (American Society of Heating, Refrigerating, and Air-conditioning Engineers) Handbook of Fundamentals.

briligg · 03-24-12, 05:58 PM

um, it doesn't seem to be loading.
i put a copy in an album i started here, 'passive solar calculations'.
also, this web address should work, i guess:
https://plus.google.com/u/0/photos/1...79245872117874

RobertSmalls · 03-24-12, 07:57 PM

That's above the clouds, right? The NRC has a really good resource for the average values below the clouds, accounting for different collector orientations. They'll even tell you how much performance improvement to expect from a sun-tracking system, if you were doing photovoltaic.

https://glfc.cfsnet.nfis.org/mapserv...illement&NEK=e

briligg · 03-24-12, 11:47 PM

Yeah, i got their data for Hamilton and ran the numbers with it, and the results just seemed too good to be true. I checked the data to some degree with NASA, i'm still looking to cross-reference it more that way. Then i ran the numbers again with the data above, and percent sunshine figures for Toronto supplied by Kachadorian's book. Calculated that way, the incoming sun was way lower. I still have to compensate for the fact this chart only gives figures for vertical glazing, but the NRC values were a full 40% higher. Just a huge difference.

briligg · 03-25-12, 12:57 AM

I think that because the NRC data was really meant for photovoltaics, when they say 'insolation' they don't mean the same thing as what someone working on passive solar heating means. Maybe they count a cloudy day as one in which 15% of the sun's energy is still available for harvesting, so it is still a plus. But for passive solar, a cloudy day that is also cold is a net loss. The remaining solar radiation has virtually no heating value. So i'm going to use the ASHRAE data.

AC_Hacker · 03-29-12, 11:53 PM

Quote:

Originally Posted by briligg

As i have been struggling to calculate the amount of sun to expect...

Have you looked into purchasing the Passive House Planning Package (AKA: PHPP)?

It'll cost you about $200, a real bargain.

It will answer your questions and a whole lot more...

-AC

briligg · 03-30-12, 12:54 PM

(huh, i didn't get an email notice there was a new comment on the thread. That should be automatic, shouldn't it?)

I bought The Passive Solar House, by Kachadorian, and Passive Annual Heat Storage, by John Hait. Together they provide all the basic data i need, the issue here was really that i sought other sources only to discover the data really wasn't applicable in the end.

The Passivhaus package likely wouldn't give me enough useful information for the project we're designing to justify the cost. It's a greenhouse, atypical in numerous ways. For instance, at the moment i'm trying to get my head around how to estimate the u-value of multiple layers of ETFE plastic with air spaces between.
But so far, any data i've really gone hunting for online, i've eventually found for free.

03-24-12, 05:34 PM	#1
briligg Lurking Renovator Join Date: Feb 2012 Location: Mexico Posts: 14 Thanks: 2 Thanked 0 Times in 0 Posts	Insulation at different latitudes As i have been struggling to calculate the amount of sun to expect at a proposed building location at about 43 deg N, finally i made a chart. I still have my reservations about its absolute accuracy, but it is as close as i can get, so i am sharing it. This is taken from the 1993 ASHRAE (American Society of Heating, Refrigerating, and Air-conditioning Engineers) Handbook of Fundamentals.

03-24-12, 05:58 PM	#2
briligg Lurking Renovator Join Date: Feb 2012 Location: Mexico Posts: 14 Thanks: 2 Thanked 0 Times in 0 Posts	um, it doesn't seem to be loading. i put a copy in an album i started here, 'passive solar calculations'. also, this web address should work, i guess: https://plus.google.com/u/0/photos/1...79245872117874

03-24-12, 07:57 PM	#3
RobertSmalls Journeyman EcoRenovator Join Date: May 2009 Location: Buffalo, NY Posts: 344 Thanks: 3 Thanked 17 Times in 15 Posts	That's above the clouds, right? The NRC has a really good resource for the average values below the clouds, accounting for different collector orientations. They'll even tell you how much performance improvement to expect from a sun-tracking system, if you were doing photovoltaic. https://glfc.cfsnet.nfis.org/mapserv...illement&NEK=e

03-24-12, 11:47 PM	#4
briligg Lurking Renovator Join Date: Feb 2012 Location: Mexico Posts: 14 Thanks: 2 Thanked 0 Times in 0 Posts	Yeah, i got their data for Hamilton and ran the numbers with it, and the results just seemed too good to be true. I checked the data to some degree with NASA, i'm still looking to cross-reference it more that way. Then i ran the numbers again with the data above, and percent sunshine figures for Toronto supplied by Kachadorian's book. Calculated that way, the incoming sun was way lower. I still have to compensate for the fact this chart only gives figures for vertical glazing, but the NRC values were a full 40% higher. Just a huge difference.

03-25-12, 12:57 AM	#5
briligg Lurking Renovator Join Date: Feb 2012 Location: Mexico Posts: 14 Thanks: 2 Thanked 0 Times in 0 Posts	I think that because the NRC data was really meant for photovoltaics, when they say 'insolation' they don't mean the same thing as what someone working on passive solar heating means. Maybe they count a cloudy day as one in which 15% of the sun's energy is still available for harvesting, so it is still a plus. But for passive solar, a cloudy day that is also cold is a net loss. The remaining solar radiation has virtually no heating value. So i'm going to use the ASHRAE data.

03-30-12, 12:54 PM	#7
briligg Lurking Renovator Join Date: Feb 2012 Location: Mexico Posts: 14 Thanks: 2 Thanked 0 Times in 0 Posts	(huh, i didn't get an email notice there was a new comment on the thread. That should be automatic, shouldn't it?) I bought The Passive Solar House, by Kachadorian, and Passive Annual Heat Storage, by John Hait. Together they provide all the basic data i need, the issue here was really that i sought other sources only to discover the data really wasn't applicable in the end. The Passivhaus package likely wouldn't give me enough useful information for the project we're designing to justify the cost. It's a greenhouse, atypical in numerous ways. For instance, at the moment i'm trying to get my head around how to estimate the u-value of multiple layers of ETFE plastic with air spaces between. But so far, any data i've really gone hunting for online, i've eventually found for free.