OT: Portable Air Conditioner for a room vs. Central air to save money?

[joec]

Does anyone have good honest links or information/thoughts on using a portable/window air conditioner in a room vs. running the central AC in terms of energy usage/cost savings?

I don’t even tend to set the temperature that low (mostly to 80c), but power bills can get to $200 which isn’t high for 3k+ house with 2 AC units (upstairs and downstairs), but I’ve seen my power bills as low as $70 when it’s not turned on the whole month.

A lot of links tend to be from people trying to sell you something so I wasn’t sure how honest the opinion is.

I work from home and the home office gets hotter compared to other rooms in the house due to computer equipment and more people in the room all day in general. Also, due to how close homes are to each other and privacy, I tend to not open the windows which would help with heat obviously.

I was wondering if there are good portable AC units which can possibly save on energy costs/(money!) vs. running the central air. I don’t mind putting those window exhaust kits since you need to kick the air out somewhere.

I’ve read it’s good to get the ones which can do both heat/cold, but other than that, I don’t know what units are good.

Maybe something which can do humidity too.

Thanks for any thoughts/advice.

[spdrun]

Isn’t 80c a bit warm? 😀

If you’re so fearful of opening the windows (I basically live /w open windows 6 months out of the year in a NYC apartment that’s closer to other homes than your house), perhaps adding an economizer to the existing system that draws in cooler outside air might be an option.

Or window fans — they’re loud enough to block any sound coming out and non 100% transparent. A ceiling fan is also nice since it mixed cool and hot air from top to bottom.

[Doofrat]

Portable AC units suck. The problem with them is simple physics. With a window mount or central air, the hot exhaust is cooled from outside air and released to outside air. With a portable unit, the hot exhaust air is cooled from internal house air and released out side. But where does it get this internal air to cool? It sucks in warm humid air from somewhere in the house into the very room you are trying to cool thus mostly nullifying the cooling you were trying to accomplish. All this at the cost of the unit, lugging it upstairs, electricity (a lot), and noise (a lot).

[The-Shoveler]

I keep having this Image of the Hitchcock movie “rear Window”.

[spdrun]

Haha, I don’t sleep on the fire escape! And no neighbors with large luggage either (yet).

Good movie though.

[FlyerInHi]

when I bought my house in vegas, the AC was not working in July. So I setup an window AC for a few days until I could have the AC repaired (needed a capacitor).

That first month, the bill was more than other months with central AC.

I did some research. It has to do with the SEER rating and how well insulated the house is.

If you want to cool just one room, you might consider a mini ductless unit (one of these you hang on the wall and the compressor is outside).

Minimum standards are pretty much what builders put in.
Older than 1992 SEER 5 or 6 (Super Energy hog)
1992 SEER 10 (energy hog)
2006 SEER 13 (30% more efficient)
2015 SEER 14

those are manufacture dates. But your house might have older AC units already produced when the house was built.

I’ve looked at houses being built in San Diego over the years. Most new houses have only fiberglass insulation. Few have radiant heat barriers.

[enron_by_the_sea]

Has anyone used Evaporative coolers ( swamp coolers?) in San Diego? Our new place does not have AC. Should I consider it? San Diego should be pretty dry for it to work.

[joec]

[quote=FlyerInHi]when I bought my house in vegas, the AC was not working in July. So I setup an window AC for a few days until I could have the AC repaired (needed a capacitor).

That first month, the bill was more than other months with central AC.

I did some research. It has to do with the SEER rating and how well insulated the house is.

If you want to cool just one room, you might consider a mini ductless unit (one of these you hang on the wall and the compressor is outside).

Minimum standards are pretty much what builders put in.
Older than 1992 SEER 5 or 6 (Super Energy hog)
1992 SEER 10 (energy hog)
2006 SEER 13 (30% more efficient)
2015 SEER 14

those are manufacture dates. But your house might have older AC units already produced when the house was built.

I’ve looked at houses being built in San Diego over the years. Most new houses have only fiberglass insulation. Few have radiant heat barriers.[/quote]

Thanks for the info everyone…

I was actually only looking at the dual hose/exhaust models where you draw in air from the outside, and also push it back outside to keep the air equilibrium I guess. My house is from 2009 so I’d assume the insulation is decent.

As this is for the office where I literally spend 18 hours a day, it gets hotter than the rest of the house since all the office/computer equipment (printers, multiple monitors, storage devices) as well as people constantly being in the room. It just gets noticeably hotter compared to any other room in the house.

I know the portable types aren’t as efficient as the window models, but I don’t really want a window one since it’s probably not even allowed in my HOA and I don’t really want something sticking out of the window.

The room isn’t too big (maybe should get one rated to 200 sqft due to extra equipment generating a lot of heat) and I probably wouldn’t need a huge one, but most models seem bigger than that for dual exhaust models and if they also have a heater and dehumidifier.

I was considering something like this which is overkill, but the prices seem to be around this range anyways for dual exhaust and the features I want (have it auto expel water, etc…):

Would be very open to smaller units with similar features (probably save more power too).

As this is also sitting in the office permanently, it would also be a business expense.

Just wanted to hear more if anyone has tried one of these.

Running the central air is ok, but I’d assume if I only need 1 room cooler than the others for most of the day and night, this would still be cheaper to run for most summer days.

[spdrun]

Buy one off Craigslist for $100 — people buy and sell them all the time. Get a window unit. Remove it if the HOA complains about it.

[CA renter]

We have a portable A/C unit from when we didn’t have central A/C, and it seems to use almost as much energy as the central air unit. Unless we’re doing something wrong, I just don’t think they’re worth the extra expense *if* you already have central A/C.

OTOH, if you didn’t have central air, I’d recommend the portable as they make a HUGE difference in rooms that just don’t cool down naturally (facing wrong way, no air flow, etc.).

[CA renter]

[quote=enron_by_the_sea]Has anyone used Evaporative coolers ( swamp coolers?) in San Diego? Our new place does not have AC. Should I consider it? San Diego should be pretty dry for it to work.[/quote]

We had one in a house I lived in up in L.A. It was a much older unit, but it worked. San Diego tends to be much more humid, though, so it might not work as well. Probably depends on where you are in SD County. Better if it’s in a very dry area like the eastern part of SD County.

[FlyerInHi]

joec, I agree with CArenter. running a portable unit is almost like running the whole house AC. those portable units and window units are huge energy hogs.

Your 2009 house is probably almost the best in terms of insulation and energy efficiency.

You might consider installing a duct booster fan to draw more cold air from the central AC system into the room that has all the computer equipment. Something you could control with a switch or a dial to adjust the fan speed.

http://www.hvacquick.com/products/residential/airflow-boosting/inline-air-booster-fans

[FlyerInHi]

Or install one of the these.
there is a range of prices. You could deduct it as a business expense since it’s for your home office.

http://www.comfortup.com/panasonic-11-900-btu-20-seer-wall-mount-heat-pump-system?gclid=CLWp_a_L3b8CFcI-MgodwzIA3A

[svelte]

Speaking of electric bills.

We have been comparing electric bills with friends in Poway (2400 sf) and Escondido (3000 sf). Our San Marcos house is 3000 sf.

All homes are roughly within 10 years age of each other. We have our A/C on 365 days / 24 hrs (wife’s instruction). They don’t.

Poway and Esco bills are more than double ours, approaching $1K/mo during summer.

They both have pools (Esco one is an extremely huge pool) and we don’t.

I’ve read that a pool increases elec use by 50%, appears to be true. Plus being further inland appears to have an effect also.

Back to original topic: we recently considered a portable A/C for a room we have over garage. It gets beat by the sun every afternoon and gets hot. Since we already have central A/C, we found the best solution to be adding a second register in that room. We did that recently and the room stays very comfortable now. Cost us $500 to have it installed (very hard to do in our attic) and love the results.

[FlyerInHi]

Adding a second register to a hot room is a great idea. Better than a duct fan which is noisy.

Wow, $500/mo electric bill would make me feel like I’m going bankrupt. Don’t even talk about $1,000/mo.

My first house still has a mortgage of $500/mo. And I’m looking forward to the day it’s paid off.

Yeah, a pool consumes a lot of electricity. Not to mention the cost of chemicals, water and service.

I’m never in Vegas long enough to have a full month’s electric bill…. but my neighbors spent about $175 in June on their 1600sf house, at 74F. They are retired so the AC is on 24/7. It’s about what a lot of people spend in San Diego, without AC.

My SD condo, is about $50/month without AC. Maybe $90 during a hot month. 1.3 persons occupy the space.

I think the mild weather in SD is causing builders to skimp on insulation.

I guess we should compare kWh to get a better idea. Desktop computers also use a lot of energy, especially if you never turn them off. Same goes with DVRs. I have a feeling that my Windows Media desktop is costing me $10/month.

[Author]

Posts