Home AC question re: Cost?

[Martinjmpr]

Well, this summer has been brutal at our house.

We moved into this 2800 sq ft 4br/3ba house in the Columbine area last year, wanting a little more space (compared to our tiny 1100 square foot 3br/1ba home in Englewood.)

House has an attic fan/ whole house fan but no AC.

The whole house fan actually does a good job of cooling the house down at night - it gets so chilly that I often end up getting up in the middle of the night to turn it off (we need either a timer or a remote control.)

But in the afternoon's it's just really uncomfortably hot, even with the windows open (we learned the hard way to NOT turn on the house fan during the day - no point in sucking hot air INTO the house.) So on these hot days, I'm seriously considering adding AC to the house. I just can't stand it when it's 4:00 in the afternoon and 90+ inside. What's worse, with my wife only working part time and me working from home 2 days a week, we're in the house a lot.

I realize that I should consult a professional for a true estimate, but I'm wondering if I can get some input as to just a ballpark figure of what it might cost to add an AC unit to a house of this size. Back about 12 years ago, my mother added AC to her small townhouse (about 800 sq ft on 3 levels) and I think her cost was about $4,000 for everything.

So would I be in the right ballpark if I figured maybe around $6000 - $7000 for a house of our size? And would I be right in thinking that it would correspondingly add approximately that much value to the house when it's time to sell?

We wouldn't think about getting it done this year, as I'm sure the AC companies would charge a "hot weather premium" to do work when it's mid-Summer, but if we can keep the cost reasonable, I think it's the best way to go. Seems like our Summers aren't getting any cooler and I don't want to suffer through another 8 miserable summers in this house (we're committed to staying here until I retire which should be in about 9 years.)

The second question is for those of you who have a similar sized house and put AC in: About how much did your electric bill go up when you added AC? Because our new house is more energy efficient than our old one, our electric bills have actually gone down since we moved, which is nice. I wouldn't mind paying an extra $30 - $50/month if it meant our house was livable during the middle of Summer.

Thanks to anyone who can offer input.

[Irving]

The house fan can really help mitigate your A/C costs by giving you a cooler house to start.

[Martinjmpr]

The house fan can really help mitigate your A/C costs by giving you a cooler house to start.

I was thinking the same thing. As I said, if we run our house fan at night, it gets CHILLY even in the upstairs, which is the hottest part of the house. If we got AC I would likely turn off the AC and open the windows when we went to bed and run the house fan all night. Then in the morning, shut the windows and turn on the AC to keep the house cool during the heat of the day.

[MarkCO]

You can keep it cooler a few ways inexpensively...

Thermal window coverings that are exposed to the sun. Foam board inserts into the windows does help.

If you have a crawl space, you can pump air from there into the attic during the day and significantly cut the temp in the house. If not, consider power venting the attic...taking outside air and circulating it through the attic during the day. Attic temps in CO in the summer get to 150ish depending. Cutting 50F off of that helps tremendously.

The good numbers I have seen in CO this year are in the range of about $4/sq/ft for decently energy efficient houses with good energy efficient AC. Our house (built in 2009) has better AC than the builder was installing (did it as an upgrade myself) and we are in the range of about $50/month for AC while the other two houses of the same floor plan are in the range of about $80/month. So efficiency does matter.

[TFOGGER]

As dry as it is here (usually), have you considered a swamp cooler? We use a window mounted unit upstairs, and it keeps the whole house(1300sf) pretty comfortable (75 ish peak). I know larger roof mounted units are a bit more expensive, but they're more effective as well.

[fitz19d]

If you spend your time mostly in certain rooms, can consider single room conditioners, depending on layout I hear they can cover suprising area if you are good about keeping doors shut. Newer ones afforable and much quiter than they used to be.

My house sucks and by late afternoon the heat overpowers the ac and creeps to 80/81 if set at 78. Considered this though just a floor fan usually works for when im just coming at the computer rather than working in the house.

[Irving]

My neighbor works for a company that sells swam coolers that do not add moisture to your house. It cools the air the same way as a swamp, but the moisture is contained and drips out of the unit itself into the yard. He's been telling me that if an A/C unit of the same size as his unit takes 4,500 watts to run, his takes 450 watts. The company is called Coolerado.

http://www.coolerado.com/how-coolerado-works/

[Irving]

As a side not, all of our Southwest facing windows have ugly 1950's awnings on them. While they are ugly, they are pretty effective. I don't have A/C, work from home and have a (small) house full of kids and dogs, and the highest I've ever seen our house was 84 degrees, but it usually tops out at 80. Even yesterday it only got to 81 degrees. Physical barriers work great.

[Ramsker]

The whole house fans are awesome . . . when it's cool enough to really work well. We run the AC during the day and then ideally let the whole house fan do its thing once it cools down at night. Lately, though, it hasn't really gotten all that cool before bedtime. I somtimes turn it on really early in the morning to get the initial temp down.

Can't wait for the cooler nights that aren't too far away. My wife hates it when I put that sucker on high and chill the whle house down in <30 mins.

[DenverGP]

For my smaller house (about 1600 sq ft) my recent AC install (along with a new high efficiency gas furnace) was around $5000, but that price was an HVAC friend of a friend picking up the equipment and doing the install. I got quotes from several hvac companies for about $9000 or so.

That said, it was worth every penny I paid for it, even if I had to pay the "regular" price.

Before the AC install, we were running a portable room AC in the living room, and a window unit AC in my office, and those ran pretty much non stop. They were noisy and only kept the house bearable not comfortable.

Our electric bill is now lower with the central air, but we did also get new windows and attic ventilation around the same time.