HVAC question-determining what size?

[ColinR]

Any of you HVAC guys mind running a calculation on what size ac I need if I PM you some details of our house?

[elliscountyhog]

Not sure how quick I can get to it but send it on over and I will ASAP. Email will be better rgwalker@walkerac.com

[Eric T.]

600 Sq Feet per ton is a good rule of thumb. Do not include the garage footage since it will not be conditioned air.

[ColinR]

Not sure how quick I can get to it but send it on over and I will ASAP. Email will be better rgwalker@walkerac.com

Email inbound

[elliscountyhog]

600 Sq Feet per ton is a good rule of thumb. Do not include the garage footage since it will not be conditioned air.

What if you have a total foam house? Homes now a days have WAY too many variable to determine size off sq footage alone.

[ColinR]

Ok so here's the deal .....

We are building a new home in Texas our builders grade of ac is the carrier heat pump 25HBC5 3.5 ton 15 seer with FX4 air handler. The ac contractor is saying I can upgrade to a heat pump 25HCB6 4 ton 16 seer with a FV4 air handler. He said the 25HCB6 does not come in half ton sizes thus the reason to move up to 4 ton. This upgrade would be $3k. Is this that much of a better system? Is the builder grade a inferior package? Or should it be fine?

[Mayhem]

seems the builder grade is the bare minimum you can get by with. I think i would upgrade to the bigger unit and in turn the bigger unit doesnt have to work as hard to the same job, so you win in the end. Maybe im wrong, just the way i see it.

[az2tx]

There are a lot of variables and I'm no expert.
Insulation type and values
Ceiling height
Window Sq Ft
Window/door exposures
one unit or multiple
These are just a few of the questions that need to be answered

[BigThicketBoy]

Tagged

[deer99hunter]

Ok so here's the deal .....

We are building a new home in Texas our builders grade of ac is the carrier heat pump 25HBC5 3.5 ton 15 seer with FX4 air handler. The ac contractor is saying I can upgrade to a heat pump 25HCB6 4 ton 16 seer with a FV4 air handler. He said the 25HCB6 does not come in half ton sizes thus the reason to move up to 4 ton. This upgrade would be $3k. Is this that much of a better system? Is the builder grade a inferior package? Or should it be fine?

The "V" is for variable speed. In a nutshell, this system will "slow down" or reduce tonnage on its' own.

It does not come in 1/2 ton size on larger equipment.

$3k is a bit much for the upgrade in my opinion.

"better system" ? Not really, but certainly more efficient.

Yes, it should be fine.

And yes, I am a Carrier dealer.

[miket]

There are a lot of variables and I'm no expert.
Insulation type and values
Ceiling height
Window Sq Ft
Window/door exposures
one unit or multiple
These are just a few of the questions that need to be answered

Yep, elliscountyhog is a pro so he can get it done. Doing a manual J load calculation takes all of that into account.

[enewman]

The money you will save between a 15 to 16 seer is about 6% according to a seer calculater. That is nothing. If it's a 3000 up grade you will not make your money back. You will replace the unit before you get your money back. The calculater I used was at .11 kw. It showd a 230 savings in 15 years. That is about the life of a unit. Yes it's a better unit only because of the ECM motor but I would save the 3000 for something else in the house.

[ColinR]

Ok thanks guys. The AC guy said that the system our builder had picked out was a very nice system. But the upgrade would just be more efficient. Sounds like that was a true statement according to y'all. Since I know nothing about HVAC I wanted a second opinion. Thanks again.