How hot does it have to get......

[sudsmaster]

My home's location is closer to the Bay than Pleasanton, but it still gets plenty hot during a heat wave. Two weeks ago it hit 98 during our two-day sizzler.

I still haven't unpacked the two 5500 BTU window AC units for the season. My solution in general is to button up the house tight in the morning. Then, when the sun goes down and temps outside are lower than it is inside, I'll throw open the windows and get the fans going. This is all helped by the fact that I put lots of insulation in the attic, and added soffit vents up there. No longer do I feel heat radiating down from above. So if I can cool off the house overnight it stays relatively cool all day.

 

[peterh770]

It's not so much the heat as it is the humidity. It has rained every day for about a month now, so any increase in temperature increases the humidity. I have a dehumidifier, but it outputs warm air, so the AC goes on.

 

[joeinfl]

I keep the air on most of the year, set to 74f

There are times when it's a little chilly in the "winter" and I turn the heat on in the morning to shower. I'm usually warm at friends houses, drives me crazy. I think the big thing here is the humidity. Right now it's just after 10PM and it's 70f and 90% humidity. I keep my air running and have had no mold issues, a friend down the street has had mold issues and rarely runs the air. (when she does it's set at about 79f which is not comfortable for me)

 

[toggleswitch2]

~I have a dehumidifier, but it outputs warm air, so the AC goes on.

Which is why I had mine on a timer to run from 10pm to 10am. Nights here get somehat cool. It created just enough heat that climbed up the basement stairs to "tickle" the central-air thermostat [which was of course in the hallway at the top of said stairs]to run more frequently at night than if it (the dehumdifier) were not "on".

Yes the dehumdifier helped dry the air, but the central system distributed the "dryness" and dried the air on the home further.

My basement was finsihed living space so I had two central air suppy ducts and vents come in near the ceiling and a return by the floor. This helped suck in and up the cold air that fell to the floor having flowed down the basment steps.

This helped keep the basement fresh and dry and sweet-smelling (why, oh why do I picture a Massengil commercial running through my head) and helped avoid stratification of air (hot on top floor; cold in basement).

 

[rp2813]

Yeah, letting the cool night air flow through the house until morning and then closing everything up tight can get you through a day or two of a hot spell, but if it lasts longer than that, pretty soon the house just doesn't cool down enough over night. Those are the bad days and thankfully we get very few of them. Interestingly, one of the absolute worst places to be during a bad heat wave is San Francisco. Nothing but asphalt and concrete reflecting heat everywhere and not even a wisp of a breeze. It must be devastating to those more accustomed to summertime temps there topping out in the mid 60's.

I've only lived in a house with central a/c once, out in one of the hot corners of the valley, and I must say that combined with an electronic air filter it was really a wonderful experience.

Ralph

 

[sudsmaster]

For a while I looked for an efficient swamp cooler: one with a heat exchanger, to separate the moisturized cooling air from the indoor air through a radiator-type of baffle. All I could find were units that blow damp air into the home - not what one wants in the relatively high humidity of the East Bay. I finally broke down and got a couple of 5500 BTU window units - with PG&E rebates, they came to about $50 each. But they are pain to install and take out each summer... and then they block some of the windows I'd like to pop open to bring in fresh air on cool nights.

It's a bit warmer in San Jose than it is up here. I'd say that we get hot spells of a week or more in which it doesn't cool down enough overnight about once a year. But the "natural air conditioning" that famed Chronicle columnist Herb Caen always liked to talk about, kicks in.

As for SF getting unbearable hot spells - well, I grew up in the inner Sunset and I can tell you that it NEVER got too hot there. Perhaps it got a bit more toasty in the Mission, but out in the Avenues too much heat was rarely an issue.

 

[qsd-dan]

Swamp Coolers

Tried a swamp cooler several years ago and learned the hard way that it took a bad situation and made it much worse!

I'd love to move to Pacifica. It's like 68F 365 days a year!!!

 

[toggleswitch2]

~and then they block some of the windows I'd like to pop open to bring in fresh air on cool nights.

I've seen some professional installs of window-rattler A/Cs where there is a metal "L" angle /bar spanning the window (left to right). It supports the unit and allows the window to be opened.

 

[toggleswitch2]

...I believe the ends are bent forwards or back to be able to screw the rod into the side of the window frame or the wall.

 

[thomasortega]

jay

21 degrees Celsius.

By the way, it was yesterday. Right now it's 19 degrees and everybody is wearing leather jackets and scarfs.
As we're used to temperatures reaching 50 degrees Celsius or a little more, 23 or 24 degrees are our average "comfort temperature". 22 degrees make we feel cold, 21 degrees make most people wear jackets, 19 degrees we look like the Michelin man, wearing heavy nylon jackets, gloves and almost wearing a king size duvet as a scarf.

When John (Lynn/Boston) visited me last January, he almost fainted. He left temperatures much below 0 degree Celsius and suddenly landed in a place with lovely 42 degrees Celsius.

We went to the brazilian side of the Iguassu Falls and he was sweating like a bottle of beer and red like a pepper. His shirt became so wet that one could squeeze it. The temperature was very nice that day. "ONLY" 47 degrees.

The good about Iguassu is the tan. Our sun isn't a broiler like in Australia or Rio de Janeiro, Salvador or other cities up north. Temperatures are very high, but not always too sunny. You don't need to go outside to get tanned, it reduces a lot the risks of a skin cancer and it's great to line dry the clothes indoors in just a few minutes.

 

[rp2813]

68

Is a heat wave for Pacifica. Same goes for San Gregorio for those clothing optional-friendly local men. Brrrrr . . . nobody ever has anything to show off at that beach! And yeah Rich, there's pretty much no such thing as a heat wave out in the avenues. The financial district is another story. When my sister lived in the Berkeley foothills, that was one of the cooler spots. The fog would stream straight in from the west and hit those east bay hills, sometimes before it would begin to blanket SF.

Heck, we just had low 80s yesterday and it was a little too warm upstairs. The nights cool off nicely but I still ran the ceiling fans all night up there.

I'd definitely install central air if I were to do a major remodel. It's becoming more and more of an expectation for home buyers. It never used to be, but it is now.

Ralph

 

[mayguy]

Thomas.

Wow,

It's 10Ëšc/50Ëšf right now, and I am in shorts, and have a couple of windows open.

We don't start our furnace till it's about 0Ëšc/32Ëšf outside.

 

[mielabor]

I must be full of saturated fats...

At work the AC is keeping the temperature at 21C or so, waaay to cold for me. My fingers get stiff and at the end of the day I'm glad to go home to warm up (25-30C these days). I have an electric stove under my desk that works year round, even during a heat wave...

The air at work is also super dry, around 20-25% RH and it took me some time to find a chair that doesn't charge me up. Before that it was always a "shocking" experience to shake hands with other persons, not to mention touching metal objects like cabinets, door handles, etc.

 

[sudsmaster]

Toggle,

Ah, so true, but in my case the windows are horizontal sliding and nearly complete "open" to hold the little 5500 BTU Daewoo chillers. I fabbed up a plexiglas panel above the AC units to give the illusion of a "normal" installation. But that panel is locked in place and can't open (unless I were to do some serious fab with a hinged window inside the plexiglass, not something I'm contemplating at this time).

It wouldn't be so bad if there was a "ventilate" setting for the AC units, but all they do is recirculate.

I don't know if I will be unpacking the AC units this summer. I might just dive into the crawl space and finish tacking R-13 insulating under the floor boards instead.

 

[autowasherfreak]

Our AC is still covered with plastic from last winter, and hasn't been warm enough to uncover and use it. It does a pretty good job of keeping things cool until it gets into the high 90's. It was in the house when we moved in and could use a good cleaning.

When it gets around 85+ with high humidity is when I start running it.

 

[ronhic]

30c or 85f here

We have 2 reverse cycle split systems in our house.

A small Dimplex (about 900 w) in our hall to take the heat out of the bedrooms and provide 'balance' to the main unit in the lounge

..and a Carrier in the lounge that is rated at about 1.9kw

With the 40c days we had in summer, they both struggled to cool the house even when started at 8am in the morning. This is because there is minimal insulation beneath the flat galvanised roof...and with no access, getting it there is a very very expensive job.

The roof itself is a clip-lock design. That is there are no visible fixings - it literally clips down. To remove the roof and add high value insulation underneath to improve internal temperature will cost at LEAST $10000....probably closer to $15000...

 

[toggleswitch2]

~This is because there is minimal insulation beneath the flat galvanised roof...

The roof itself is a clip-lock design. That is, there are no visible fixings - it literally clips down. To remove the roof and add high value insulation underneath to improve internal temperature will cost at LEAST $10,000....probably closer to $15,000...

Not familiar with this type of roof. Care to share details/links here or create a new thread?