Design Conditions

Dave Yates (GrandPAH)

Digital stat read 108F (in the shade) at home two days ago. Calls are virtually non-stop now for A/C. "I have my thermostat set for 72F and......." You know the rest of that sentence(G). We're a bit past "design conditions", which defaults to 95F in most calc programs (I use 100F).



Attic located units and ducts really take it on the chin in this weather.



So, how hot is it where you are?

Mark Eatherton

It might hit 70 here today....

Did I mention I am at 8,000' ASL? Minor details...



Heck, if it does get to 70 today, I am gonna put the barge in and see if I can find some 65 degree weather, in the sun :-)



I feel for you all with high temps and RH.



ME

Jean-David Beyer

how hot is it where you are?

I remember one morning in 1995 I got to the Amtrak station in Chicago in mid morning. I had been in an air-conditioned train from New York City, so I did not realize how hot it was outside. The station had been newly rebuilt since the last time I was there. It was so hot in there I could not believe it. How could they design such a building without air conditioning! It turned out they did have air conditioning, but whatever heat load they designed for, it was exceeded. Apparently about 700 people died from the heat in Chicago that week; the temperature got up to about 106 degrees outside. I walked over to the Art Institute that had better air conditioning, and stood next to one of its outlet registers for several minutes, then went to their restaurant for lunch, looked at pictures, etc., before I caught my 2:15 train to Seattle.



At 11:25 or so this morning here in New Jersey, it was 86F in the shade according to my Kodak Process (mercury) thermometer that is accurate to +|- 1/4 degreeF. Since July 1, when I reset my cheap Radio-Shack Indoor-Outdoor thermometer, it has peaked at 103.6F. And now it reads 86.7F in the shade. That sensor is not in the same place as the other one. The 103.6F reading was probably on Monday.

Bob Bona_4

calm before the storm

Dave. Ct was 102. 112 in my truck cab..my A/C has a leak and I have been meaning to get to it. For the last 5 years

"I have the thermostat set at 68, and it won't cool down past ________" insert appropriate number. Oh, yeah.

Was thinking of you GrandPAH. Did a Fujitsu HP 1.5 tonner yesterday. 19.2 SEER. 38 degree discharge temp on cooling @ 90 in condenser shade, 121 degrees discharge on the heat pump. Wowsers. This generation of inverters are BEASTS. 60 degree split??!!!

Wait for the sound of the phones ringing about tortured and inop equipment after this heat wave passes!

NRT_Rob

past design

here in maine. our brand new spiffy radiant cooling system, without even proper control on it yet, kept us at 77 Deg F. with roughly 95 Deg outdoor and heavy RH.



once we get the dehumidistat in and such I imagine 75 to 76 would work just fine.



do most of you guys find people setting 72 Degrees on their cooling stats? maybe it's the radiant, but we found 77 quite comfortable. right now we're at 76 and about 55% RH or so. feels great... I think cooler would feel *cold*. but then, I always hated AC...

Dave Yates (GrandPAH)

yup

They'll leave it at 78F until we hit design conditions & then crank-er-down to 72 & get all steamed up because the unit runs 24/7 and never gets there. We spent waayyyy too much time testing a 3-ton unit for an elderly customer who insisted there was something wrong because the room temp won't dip below 76F on these hot days. Superheat, subcooling, air split across the condenser, air split across the air handler (in the attic - of course), and given that it's a 16-SEER 2-stage model, we checked the dip switches to guarantee 1,260-CFMs were being sent into the ductwork that's properly sized for just 3-tons (not our install). Checked it every way from Sunday & it is producing exactly what the manufacturer's specs say it can produce. "It worked much better last year." Doesn't want to hear how it barely broke above 95F last year. She called again today   I asked her if it was -10F would she expect her boiler to heat the house to 80F? Would she turn off the heat and expect the home to return to the thermostat setting within an hour? (She's been turning off the A/C at night to save energy!!!) You know the answers: "Yes" It's like she's from Stephen King's next novel!



Sized my own A/C for 78 on a 100F day, which is exactly what it can achieve. Was 82F indoors when I got home yesterday. Nice-n-comfy 76F by bedtime. Patience & cold libations.



Selling tons of Fujitsu too(G). Many folks have reached their limit for lugging 12K Btu window-shakers up from the basement. "No more!" One retired customer fell & broke several ribs on the cellar steps, which led to them agreeing to a 28-SEER inverter model. But, he gets out of mowing the yard. Said he was due to get released from his work-release & get back to mowing. I suggested he milk this for all it's worth(G). They absolutely love it & the wife has her garden view back now that the big hunk of an old window unit is gone from her favorite window. Peace-n-quiet with less humidity and far less power consumed. And a remote controller - what guy doesn't love a remote! Psssst - c'mere: you can set the temp, point it at the unit, and then hide the remote(G).



Man, am I gonna miss those sweet tax credits.

Bob Bona_4

annnnndddd here,

folks get back 5 bills from the local utility if ya make ARI 16 SEER. It's fun seeing VS air handlers coupled with 15 SEER condensers make the certification. Plus, the state has just about wrapped up the 2010 appliance replacement rebate of another $500. Cash. Throw in the Fed credits, and it don't take too much sellin' skills

Personally, I like it cold. After losing a quart of sweat working outside, I want my A/C when I get home!  Wife keeps it 76-78 during the day, and I've just about worn the touchscreen down to nothing tapping it down to 72. I'm looking at the office hygrometer, and it's saying 48%.

If I ever get to have any extra cash, it's Honeywell's Red Link wireless remote control for me!



 

bob eck

hot outside

101*F Allentown PA

If the home owner thinks their A/C is not working and only can get it down to 78*F and they want it down to 72*F tell them to go sit outside for a hour or two then come back into the house 78*F will feel great vs 100*F + weather outside the house. Some people must want to feel like living in a refrigerator.

Stay cool don't get over heated before you know it it will be winter and the same people will be complaining that there heating system is not making it warm enough.

bob eck

hot outside

101*F Allentown PA

If the home owner thinks their A/C is not working and only can get it down to 78*F and they want it down to 72*F tell them to go sit outside for a hour or two then come back into the house 78*F will feel great vs 100*F + weather outside the house. Some people must want to feel like living in a refrigerator.

Stay cool don't get over heated before you know it it will be winter and the same people will be complaining that there heating system is not making it warm enough.

Alan (California Radiant) Forbes

Traveling

In Colorado Springs for a bike race. Like Mark, we are at elevation (7,000') and temps. are in the mid-80's

Mark Eatherton

Triple By-Pass?

Alan, Are you doing the triple bypass or something else?



How long will you be around? I think I owe you a tour and dinner or something :-)



ME

Fortunat

What happens when you open the bay door

Rob,



this has indeed been a great week for testing the radiant cooling.



So what happens when you take a delivery at mid day and the bay door is open for 10-15 minutes? have you had any indoor rain yet in your warehouse?



~Fortunat

Ron Jr._3

When's it too hot ?

Talking about attic work ...........



Was replacing an air handler and condenser last week . Temp in the attic hit 130 . We'd work for 1/2 hour and take 15 , over and over . The jury rigged fan we carry just wasn't doing it that day . Gotta look into a portable unit .............

Alan (California Radiant) Forbes

Traveling

Hi Mark:



We flew through Denver and Boulder to stay in Estes Park and then Granby for the US National mtn. bike race this weekend. We left early and are now in Gunnison and then

to Crested Butte for week. Will have to catch up later, dude.

Larry Weingarten

I've got some grey poly...

... pipe foam insulation outside.  It's not on a pipe, just in the Western sun and it's melting!  That tells me it hit around 180 degrees in still air here in central California.



Yours,  Larry

Mark Eatherton

Dude....

You were a maximum of 30 minutes away from my mountain hold out.



In fact, if you went from Highway 40 to I-70, you drove right by me.



You remember the big lake (10 miles long) between Kremmling and Dillon on the right hand side of the road (Colorado Highway 9)? That's my hide out.



Warn me the next time and we'll get together.



Travel safe my friend.



TLLA says hello.



ME