[Greenbuilding] [BULK] Re: solar payback (+ VWs + HRVs)

[Lawrence Lile]

On Fri, 30 Nov 2007 14:13:44 -0500, Lawrence Lile <LLile at projsolco.com>  
wrote:

> Here is how you can justify a solar power system right now:
>
> Decide on loads that absolutely need to run during a power outage, like
> a computer, cell phone chargers, a single compact fluorescent bulb, or
> some other combination of small loads that you'd rather not do without
> in an outage.

[gizmo-intensive suggestions <snipped>]

Well L-man, I was (sort of) with you up until this point but the following  
is IMO a bad analogy.

> Of course people also spend $50,000 for a car with leather seats that
> goes no faster, legally, than a used volkswagon beetle.  Where's the
> payback there?  None I can see.


I've yet to meet a Volkwwagen Beetle (or any Volkswagen ever, for that  
matter) that didn't require an engine overhaul after 30k miles.

As is the case with ground-source heat pumps that have the nasty habit of  
failing and requiring new heat exchangers every 3 years , "payback" is an  
alien concept in such scenarios. OTOH, if you had used "240 series Volvo"  
(which are bullet-proof and never die) in your comparison, then we'd be  
cooking with (bio)gas.


And speaking of alien concepts,

someone wrote in another thread and which ended up in a post by L-Man:

>  Is the HRV (vs a simpler exhaust fan) also de rigeur? HRVs seem useless
> in most US homes, which naturally leak about 10 times more fresh air
> than required.

To which I say "HUH ?".

What do monstrously air-leaky, energy-sieve homes with their attendant  
crappy indoor air quality have to do with Green building ?  (Yes, HRVs are  
de rigeur in superinsulated homes built in Cold Climate regions and which  
are necessarily built to be air-tight.)

If by "simpler exhaust fan" you mean exhaust-only, passive-inlet  
ventilation strategies (EOPIVS) ... testing done about 10 or 15 years ago  
here in Canada showed that EOPIVS do not work in all but the most mild  
Banana Belt locations in Canada, do not work in multi-storey homes and do  
not work in homes over ~1600 sf.

And "no" , one would not connect the range or dryer exhaust directly to a  
duct to an HRV.
And that being said, apparently 75% of HRV installations are configured  
improperly.
D'oh!  (That is to say, don't let your HVAC contractor design your HVAC  
system.)


-- 
=== * ===
Rob Tom
Kanata, Ontario, Canada
< A r c h i L o g i c  at chaffY a h o o  dot  c a >
manually winnow the chaff from my edress in your reply


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