What's up today (bullchiting) thread.

T.Jeff Veal you would be amazed the number of times in construction, major problems can be solved by reading the flippin instructions

 

5 ton is a big unit! Is the house big enough to need that?
Going too big on ac will cause the unit to cycle too much and not dehumidify.
That said, too small ducts can cause them to ice the coil up, and that's too small on the supply or return side...it's a system, and all has to work together.
(2) 20x20 ducts, that's huge for a home...how big is this place?
I would expect a 2 ton to cool most houses fine, 3 if it's a little larger or poor insulation/air sealing

 

28x66 black metal roof, open field, no shade...

 

Oh, I know, brother Lyle. I worked in construction for several years...I remember one job I was on, electrical blueprints showed where to install emergency lighting...somebody forgot to tell the mechanical engineer and he had huge HVAC unit installed in that spot......
In our son's case the ducts were sized for the previous unit, they may have to add a 3rd return line

 

That less than 2000 sq ft...I find it VERY unlikely he needs a 5 ton unit...even 4 sounds like plenty to me. (painting that roof a lighter color would help a lot too)
Up here I'd say 2 tons would do the job on most houses that size, 3 if you have some inefficiencies to make up for.
It's hard to find HVAC guys that really know what they're doing on sizing anymore...everyone just wants to give it a SWAG

 

My house is around 2K sqft and I have a 2.5 ton unit. The AC runs a lot, which is good in my opinion. Keeps the humidity down. 5 ton unit would feel like a blast chiller and probably constantly cycle on and off.

 

Yup.
Except the blast chiller part...since it will cycle a lot, the register temps will be warmer at first, until the duct temps normalize, and even then with the humidity being higher it won't feel that cold.
My place is ~3k ft if basement is included (I do have a couple registers open down there) and is 1940 vintage brick cape cod style...the insulation has been upgraded from "minimal" to a bit better than what would be typical in an average older home. Our 3 ton AC will run maybe 3-5 times per day when its 85-95 out, maybe 1 to 2 hours at a time, depending on what's going on in the house (hot showers, cooking/baking, etc) That's with a 2* swing on the T-stat (setpoint +1 to start, setpoint -1 to shut off) and I feel like things are pretty well optimized.
Electric bill goes up about $20/mo. when running AC, maybe as much as $40 if it's a really long hot spell.
The kids bedroom is the whole upstairs (all one room, ~750 sq ft) and I put a 5k BTU window unit up there to help control the temp better, since it would take a second T-stat and some motorized dampers in the upstairs ducts to really control the temp up therewith the central AC...window unit does a nice job and was only $50 used.

 

Do you always read the instructions?

 

Currently at a little concert at the park not far from our place. It's still hot but we are in the shade of one of the trees here. Humidity today was off the charts stupid. Heading to the hospital job for overtime tomorrow morning.

 

Looks like you touched a nerve with somebody.....

 

On my way up the driveway after work today I spotted these little ones.

 

If I am unsure of new products or applications; yup usually before hand; when I was a rookie all the time it’s an 18 page booklet on a speed square. Heck half of new house wraps have overlap and fastening instructions on them.
My shingles on my personal home are hurricane nailed…
It’s not what you know
It’s not what you don’t know
It’s what you don’t realize you don’t know that bites you arse!
Plus I like listening to old timers; if you show them respect buy them a drink/lunch/coffee most will give you life lessons worth years of experience.

 

Yup. I'll be glad to move on to the inside work.