The good ole' hot room problem!

[stream41]

Hi guys, we're having a problem with a couple of hot rooms, and I thought the HVAC forum would be the best place to ask. We have a house that's roughly 3.5 years old and well-insulated (as far as we know). We have two front bedrooms that directly face the eastern sun all morning. Those two rooms also have very large windows, and the room that gets the hottest also has a crescent window above the main window. We're talking big windows - they take up 70 to 80% of the walls. This is a one-story house. I don't know specifically what type of windows are installed, but I suspect they're just the basic "entry level" window that a builder would choose by default.

We set the thermostat on 76/77 during the day, and the main rooms and other bedrooms stay at about 76 to 78 during the day. However, those two front bedrooms get well up into the mid 80's. I'm thinking that it has to be the windows letting in all the heat, right? Both rooms have one A/C vent, with no return vent, and we leave the bedroom doors open. The rest of the house stays where it "should" be, and the only difference between these rooms and the rest of the house is the huge sun-facing windows.

We were thinking of having the windows tinted as a first step, before we dive into a bunch of expensive HVAC work. What do you guys think? I know this is sort of a vague problem without knowing a lot more details, but I'm just doing some brainstorming at this point.

[JWWebster]

I set my thermostat for 72 this time of year during the day. For 10 months of the year it is summer here. 77 or 78 only works at night and that is with a fan going.
 Have you thought about maybe some shade trees in front of them windows? We also use indoor wooden blinds/shutters. They are expensive but block out sunlight on hot days and allow more sun in during colder months.

[stream41]

I set my thermostat for 72 this time of year during the day. For 10 months of the year it is summer here. 77 or 78 only works at night and that is with a fan going.
 Have you thought about maybe some shade trees in front of them windows? We also use indoor wooden blinds/shutters. They are expensive but block out sunlight on hot days and allow more sun in during colder months.

Whew! We'd have a $400 electric bill if we did 72 during the day! Those rooms do have wooden blinds, which stay closed shut all day. You can still feel the heat radiating into the room from the windows if you stand in front of them.

So you wouldn't put much stock in the tinting idea? Our veterinarian here in town had his windows tinted in his building, and he said it made a dramatic difference with their heat problem. That's what got me thinking about it.

[JWWebster]

Window tinting may not be a bad idea. I did my van. What you do is wet the glass with windex and apply the tint. Do it at night when the heat ain't hitting the glass. Work the wrinkles out quickly before the windex drys. Let it dry out naturally and it probably will help. I know it does in my van. That is when I actually have the doors on the van. It is so hot I took them off. LOL 440 ac 4 doors removed@40mph 

[ApplianceGuru]

I had friend install reflective tint (reflective on the outside) on his windows, and it helped out quite a bit.  He tinted the whole house.  It is pretty darn dark inside, maybe too dark.

[stream41]

Okay, cool, we may start with that then.

If that doesn't help enough, what would our HVAC options be? Or rather, what would be the cheapest HVAC option we should try first?

[JWWebster]

Add small window units to them rooms.

[RegUS_PatOff]

adjust the Dampers (partially closed) inside the Supply Vents to each of the other rooms.

[jumptrout51]

What zone are you in?
What is the square footage of the house?
What size condensing unit do you have?
Where is the air handler installed?
Where are the supply ducts in these rooms in relation to the doors?
How high are the ceilings?
House foundation slab or off-grade?

[niobrara]

All good ideas, try putting a small fan in the rooms, out.

[JWWebster]

Saw a fancy split system down at the parts store. It comes with 3 individual evaporators that can be hung in different rooms on the wall. The HVAC parts guy says his FIL has a couple of em installed in his house. They doing a pretty good job. Get this the thang was only $1500 bucks and it is a heatpump!

[stream41]

What zone are you in?
What is the square footage of the house?
What size condensing unit do you have?
Where is the air handler installed?
Where are the supply ducts in these rooms in relation to the doors?
How high are the ceilings?
House foundation slab or off-grade?

I'll answer the ones I can:

1) What's a zone? Do you mean climate zone? If so, I'm in central Arkansas
2) 2150sqft
3) I believe we have either a 4 or 5-ton unit, I'll check to be sure. We've had an HVAC guy tell us in the past that it's the right size for our house, FWIW
4) In the attic
5/6) The ceilings are vaulted, and about 12 to 14 feet high at the peak. The supply vents are about halfway up the "triangle" side of the vaultings. Not sure that makes sense - I can take a pic if needed. They're probably....6 to 8 feet from the doors
7) Slab foundation

[jumptrout51]

More supply ducts in these rooms would have been better,but,too late now with vaulted ceilings.
4-5 tons is right for footage.
Check the air handler for air leaking out around seams.
Use metal foil tape to tape all air handler seams.
Squeegee the tape down for a tight fit.
TINT THE WINDOWS. Use reflective tint.

[stream41]

More supply ducts in these rooms would have been better,but,too late now with vaulted ceilings.
4-5 tons is right for footage.
Check the air handler for air leaking out around seams.
Use metal foil tape to tape all air handler seams.
Squeegee the tape down for a tight fit.
TINT THE WINDOWS. Use reflective tint.

Okay, good advice! Is there a reflective tint that looks relatively "normal" - or will it all be pretty dark? Do you know an approximate (just looking for a wild guess here) price I should expect to tint two 6'x8' windows?

[jumptrout51]

You might consider this product by 3M company.
http://solutions.3m.com/wps/portal/3M/en_US/Window_Film/Solutions/Markets-Products/Residential/Sun_Control_Window_Films/Prestige_Series/
Click on their dealer link for a dealer near you.
As JW said "do it yourself".