Heat Lost Factor

Big Ed

I agree this 1920's construction is not on my charts. And could see the reason why it is not. I could not find plaster walls on constantin site either,but I did book mark the site...Thanks.Maybe I should test the wall my self..I fudged and used a very low R factor wall and it still came in less then 50 percent then the boiler they have now.. The house was a 3400 square foot summer home over looking the bay until someone installed oil heat in the 30's. Thank for the input....

Big Ed

Heat Lost Factor

What would be the heat lost factor for a Brick and plaster wall with a 1 1/2" non insulated space between them ?

Constantin

Here is a good resource,

try the Colorado Energy web site, as it has R-values for a lot of common building materials. Each layer is additive. So, for example, your wall R-value may approximate something like this:

Layer	R-value
Exterior Air Film	0.17
4" Brick	0.44
Air Space (1-4")	1.00
5/8" gypsum board	0.56
Interior Air Film	0.68
Total	2.85

HTH. Cheers!
[Edited to include plaster board]

Weezbo

big ed,

there is a bit of a problem with that,here are a few reasons,one is that the pattern and depth of the bricks and the workmanship,another is the air infiltration rate of the wall in question,and where the dead air space communicates with, inside the building envelope.. it may not be what you wanted to hear....

Constantin

Note the update...

...sorry that I forgot about the plaster. I've substituted 5/8" of gypsum for plastered walls.

It doesn't change the results much, and like Weezbo has warned, infiltration is likely to be a real problem. If this is a year-round home now, a good insulation job may pay for itself in a few years.

[Edit: Tim would like to point out that the above information I gleaned from the Colorado web-site is inaccurate and/or applied inaccurately. For example, the brick used in wall construction is allegedly quite different from the face brick the site seems to be modeling. Plus, if it's a true brick wall, chances are that there are multiple layers of brick. Etc. YMMV and all that good stuff. ]

Tim_24

Thanks

for putting words in my mouth! However, what I would really like is, that if one chooses to provide information, that it be accurate (as can be). The details of this wall construction were not provided. You assumed a single row of face brick. As a "mere homeowner", (your favorite, incomplete disclaimer) the possiblilty that walls are not constructed in such a manner may not have occured to you. Those who may have familiarity with a brick wall would know different. Rather than to admit that you know not about which you post, you choose to poke at me in your editorial. I can see why so many professionals here hold you in such high esteem.

Constantin

Say Tim,

Did the OP specify the wall thickness or not?

Plenty of walls are built with a single layer of brick on the outside, with other materials doing the structural work. Presumably, the OP would account for multiple layers, if there were any. Also note the wording, which is "may approximate something like this", NOT "does" or other definitive descriptions. After all, the OP did not specify the wall construction in its entirety.

I could also go on about editorials from your side, yet I choose not to. Constructive criticism written in a non-belligerent manner is much more helpful, IMO. You've apologized for your writing style in the past, yet do not seem capable of changing the tone. That is an improvement opportunity. Similarly, there is a lot I could learn about R-value calculations and many other things. That is why I frequent this site.

However, I disclaim what I write for a reason, and I do not hold it against you, for example, that you used to think that reflective types of insulation had high R-values when used under foundations. How many homes are potentially at risk for cold slabs due to Reflectix, Insultarp, or whatever being specified by you below the slab instead of the R-10 or whatever you were aiming for?

In other words, we're all here to learn, we all make mistakes, and hopefully we won't make the same mistakes twice. Cheers.

Tim_24

Plenty of walls

> Did the OP specify the wall thickness or

> not?

>

> Plenty of walls are built with a single

> layer of brick on the outside, with other

> materials doing the structural work. Presumably,

> the OP would account for multiple layers, if

> there were any.

>

> I could also go on about

> editorials from your side, yet I choose not to.

> Constructive criticism written in a

> non-belligerent manner is much more helpful, IMO.

> You've apologized for your writing style in the

> past, yet do not seem capable of chaging the

> tone. That is an improvement opportunity.

> Similarly, there is a lot I could learn about

> R-value calculations and many other things. That

> is why I frequent this site.

>

> However, I

> disclaim what I write for a reason, and I do not

> hold it against you, for example, that you used

> to think that reflective types of insulation had

> high R-values when used under foundations. How

> many homes are potentially at risk for cold slabs

> due to Reflectix, Insultarp, or whatever being

> specified by you below the slab instead of the

> R-10 or whatever you were aiming for?

>

> In other

> words, we're all here to learn, we all make

> mistakes, and hopefully we won't make the same

> mistakes twice. Cheers.

Tim_24

If learning is

the reason for your frequent visits, reading is better that posting. Posting on something that you have yet to learn is, IMHO, irresposible. When those here, a great many of which have more experience and knowledge than you or I, correct your lack of information, you may want to take it for what its worth and move on, instead of "quiveling". I am direct and at times abrupt, and I have no intention of changing, whether I offered apologies in the past or not. You and everyone else will never have any ambiguities about where I stand or what I think.

Constantin

Wonderful

Tim, if you recall, I thanked you for your feedback and perspective in a previous thread. If none of us posted on anything we weren't masters of the universe on, there would be little to no replies on this site. Thankfully, it is not so. Lest we forget, you too have been shown to be fallible regarding the properties of insulation, among other things.

So, if you were to apply the rules you advocate to yourself, you wouldn't post either because doing so would be "irresponsible". However, if you hadn't posted your belief that Reflectix or whatever has a R10 value when used in a sub-slab scenario, you would still be calculating erroneous heat loss calculations, still be overselling a product to your supply-house clients, etc...

...so was it not to your benefit to find out that you were duped by a supplier into thinking that a product couldn't possibly provide the kind of insulation that he/she claimed it could? Frankly, considering your long-time experience in the HVAC field, I am surprised you fell for the false promises of the reflective insulation industry in the first place.

Again, I appreciate your feedback and I respect your opinions. However, please don't expect me to always to agree with you and I won't take it personally either if you disagree with my posting style or content. Cheers.

Tim_24

I am guilty

of opening my mouth only to promptly find my foot firmly planted there.