A/C units

[spidey07]

Originally posted by: dartworth

Originally posted by: Thegonagle
Definitely get the energy saver if your utility company offers a rebate. The rest of the difference will be made up within a few years in energy costs.

In my area, Xcel Energy is the service provider, and the high-efficiency central-air rebate is between $250 and $350.

They also offer somethhing called the Saver's Switch, which they install for free, and then give you a 15% discount on your electric bill from June through September. The catch is that they're allowed to cut the power to the outdoor unit 50% of the time (15 minutes on, 15 minutes off) on the hottest days of the year. Of course, that can be compensated for by installing a slightly oversized unit that can cool the house more quickly.

See what your local utility offers before you make any final decisoins. It might really pay off in the long run to go with a high-efficiency + oversize unit w/ saver's switch, if you'll be staying in the same house for several years.

Oversizing is never a good idea...

a it is a LOT better than undersizing. think about it a little larger unit doesn't work as hard.

I can't tell you how many folks can't keep their house below 78 in the summer. talk about miserable. and these are 300K homes.

builders will skimp on anything.

 

[dartworth]

Its always better to be slightly undersized than to oversize it..especially in humid climates.

 

[Ornery]

"a it is a LOT better than undersizing. think about it a little larger unit doesn't work as hard.

I can't tell you how many folks can't keep their house below 78 in the summer. talk about miserable. and these are 300K homes.

builders will skimp on anything.

You don't have a clue about the reasoning behind this. It's because an oversized unit would cool the house too quickly. It wouldn't have a chance to remove the humidity. You'd be living in a clammy house, instead of cool and dry. The unit has to be sized properly, not too big, not too small. Ca pish?

 

[spidey07]

Originally posted by: Ornery
"a it is a LOT better than undersizing. think about it a little larger unit doesn't work as hard.

I can't tell you how many folks can't keep their house below 78 in the summer. talk about miserable. and these are 300K homes.

builders will skimp on anything.

You don't have a clue about the reasoning behind this. It's because an oversized unit would cool the house too quickly. It wouldn't have a chance to remove the humidity. You'd be living in a clammy house, instead of cool and dry. The unit has to be sized properly, not too big, not too small. Ca pish?

gotcha. I'm not a HVAC guy. Just an engineer.

I overbuild everything.

 

[spidey07]

Originally posted by: dartworth
Its always better to be slightly undersized than to oversize it..especially in humid climates.

c'mon down to the ohio valley where 80% humidity is the norm

 

[dartworth]

Originally posted by: spidey07

Originally posted by: dartworth
Its always better to be slightly undersized than to oversize it..especially in humid climates.

c'mon down to the ohio valley where 80% humidity is the norm

I live in Ohio.

That is exactly why you don't oversize the unit. It will never be on long enough to remove the humidity. It will also cycle off and on more frequently, which means a shorter life for the unit.

If you want to live in a cool house, but walk around feeling all clammy and damp, then an oversized unit is for you.

While you might think you know what you are talking about...

YOU DON'T

 

[spidey07]

Originally posted by: dartworth

Originally posted by: spidey07

Originally posted by: dartworth
Its always better to be slightly undersized than to oversize it..especially in humid climates.

c'mon down to the ohio valley where 80% humidity is the norm

I live in Ohio.

That is exactly why you don't oversize the unit. It will never be on long enough to remove the humidity. It will also cycle off and on more frequently, which means a shorter life for the unit.

If you want to live in a cool house, but walk around feeling all clammy and damp, then an oversized unit is for you.

While you might think you know what you are talking about...

YOU DON'T

c'mon. be nice.

I already said I wasn't an HVAC guy. I was just relaying my experience with many dissatisfied couples who's HVAC couldn't cool their house.

-edit- it runs 24x7 but never goes below the high 70s.

 

[dartworth]

Originally posted by: spidey07

Originally posted by: dartworth

Originally posted by: spidey07

Originally posted by: dartworth
Its always better to be slightly undersized than to oversize it..especially in humid climates.

c'mon down to the ohio valley where 80% humidity is the norm

I live in Ohio.

That is exactly why you don't oversize the unit. It will never be on long enough to remove the humidity. It will also cycle off and on more frequently, which means a shorter life for the unit.

If you want to live in a cool house, but walk around feeling all clammy and damp, then an oversized unit is for you.

While you might think you know what you are talking about...

YOU DON'T

c'mon. be nice.

I already said I wasn't an HVAC guy. I was just relaying my experience with many dissatisfied couples who's HVAC couldn't cool their house.

Well that could be from various problems, not just a undersized unit...

 

[Ornery]

"I already said I wasn't an HVAC guy. I was just relaying my experience with many dissatisfied couples who's HVAC couldn't cool their house."

I think most people solve that by having two units. One for the upstairs, and another downstairs. That's for really big houses though, not the 2,200 sq ft JM is getting quoted.

 

[Thegonagle]

I'm curious: If oversized is bad, because it will cool to quickly to properly dehumidify, what is the proper duty cycle for the correctly sized unit on a typically hot, humid day for any given region. (For example, in my area, a very hot day would be 95 F with the dewpoint well into the 70s.)

50%? 70%? 90%?

 

[Ornery]

It's not the extreme days that's gonna getcha, it's the normal hot days that will cause the problems.

Edit: I'm not sure about this, but I think if you live in a place that's generally not humid, you can use a "swamp cooler" instead.

 

[JulesMaximus]

Well, I got the first quote. $4100 for a Carrier 38TXA 14 SEER unit or $2695 for a Payne unit that uses Freon. Also, my furnace is a 4 ton unit so that is the largest A/C unit I could install. He recommended a 4 ton. We will see what the other bids come in at.:roll:

This guy seems quite high though.

 

[SarcasticDwarf]

Originally posted by: Thegonagle
I'm curious: If oversized is bad, because it will cool to quickly to properly dehumidify, what is the proper duty cycle for the correctly sized unit on a typically hot, humid day for any given region. (For example, in my area, a very hot day would be 95 F with the dewpoint well into the 70s.)

50%? 70%? 90%?

Make sure you specify residential. Commercial units are expected to run more often due to the openening/closing of doors.

 

[Ornery]

Those guys are all going to be high. They've got a lot of overhead to pay for. I had a guy come out and quote me, who I knew from high school. We weren't friends in school, but we knew each other, and had mutual friends. I figured, if he was among the lowest quotes, I'd have him do it.

He leveled with me, and said he didn't figure he would be the lowest. He said he owed it to his employees to make sure the company was still in business next year, so he had to charge enough to be sure that happened. He said there's a lot of competition, and if I checked the yellow pages from year to year, I'd see a lot of new HVAC companies pop up, then disappear the next year.

I'm sorry to say, I did go with the lowest quote, but it was by a guy who did commercial "air handling" by day, and moonlighted as an HVAC guy. No overhead, plus he knew his sh|t. If you want the best price, find a guy like that. In the end, the equipment is all pretty much the same. A 10 SEER from Trane is about the same as a 10 SEER from Carrier. There are subtle differences, but not enough to warrant several hundred dollars more. It's like the difference between a Dell 2.6GHz and an HP 2.6GHz PC. Really, how much difference is there in those boxes? I actually got vastly different quotes from guys selling the same equipment! Each company has a price point they want per job.

 

[dartworth]

I went and priced all the equipment I need for my house. It came to about $1100.

Hopefully I'll have it installed by the end of the month.

This is a 90+ furnace and 12 SEER condenser. Figure I will go with the a higher efficiency units...

Add a few more $ in for a Space Guard air filter and an Aprilaire Humidifier.

 

[Shyatic]

Call PSE&G or your local electric company and see if they offer units thru them. They usually provide service on them (7 days a week) included in the price so it pays to buy from them, and their models and pricing is usually pretty competitive.

 

[JulesMaximus]

I can't even find pricing online for the units I'm looking at.

Carrier doesn't show prices or costs on any of their units.

 

[SarcasticDwarf]

Originally posted by: JulesMaximus
I can't even find pricing online for the units I'm looking at.

Carrier doesn't show prices or costs on any of their units.

Yeah, that's because Carrier has the pricing tier I mentioned above.

 

[dartworth]

Originally posted by: JulesMaximus
I can't even find pricing online for the units I'm looking at.

Carrier doesn't show prices or costs on any of their units.

It isn't easy to buy directly from a distributor. You often have to be a contractor.