Load Cal question??

[rickytz7111]

I have a question about load cals. My installer dropped off a heat load cal to my wife this morning. Is there a cooling cal that should have been done as well? I have not even seen the paper yet. My installer keeps telling me it's ok for my system to run 5 minutes on and 5 off. Or sometimes even less. Thanks for any help. I'm starting to get really frustrated with all of this.

[Daltex]

The heat gain is the cooling load.

[rickytz7111]

Thanks. I will check all the paper work when I get home. So do they do a load for heating a house and what would that be called? Thanks

[Daltex]

Heat loss.

[rickytz7111]

So they should do one for both? Also would it be possible to need a 3 ton ac system and a 4 ton furnace? Or could that even happen?

[beenthere]

Yes, that can happen.

Bet the load calc says you need 3 tons.

[rickytz7111]

The load calc came out to 3.75 tons. So is this 4 ton to big or just a little oversized? Thanks again for all the info.

[beenthere]

I've never had a problem with short cycling when the A/C was a 1/4 more then hte load calc said was needed.
Once a contractor installs an A/C. If he does a load calc because the customer says it short cycles. He can make the load calc say what eve he wants.

Did they give you the full load printout, or just the summary.
If the full printout. Look for things out of place. Like the house direction. Lower insulation values. High infiltration rate. Higher OD temp, etc.

[rickytz7111]

I just got the summary

[udarrell]

I have a question about load calcs. My installer dropped off a heat load calc to my wife this morning. Is there a cooling calc that should have been done as well? I have not even seen the paper yet. My installer keeps telling me it's ok for my system to run 5 minutes on and 5 off. Or sometimes even less. Thanks for any help. I'm starting to get really frustrated with all of this.

I don't want any of my A/C equipment, "on 5 & off 5 minutes," it takes 5 to 7 minutes to get to decent cooling. The heat-gain would appear excessive if it only stays off for 5 minutes. Is a diffuser blowing at the t-stat? (In my book, that equipment is oversized.)

At normal room temp operation (76 down to 74-F) , I would use a digital adjustable t-stat & let the room temp vary a couple degrees within a cycle.

You will save on equipment wear, & by using a 20" fan to circulate the air & at 50% or less RH you will be comfortable at say, 77 to 75-F. - Darrell

[rickytz7111]

I'm sorry let me restate something. Since I have turned my cooling droop function off and turned my fan to auto instead on running cont. My run times are still kind of short 5-15 minutes being the longest and with long off time now. Last night at 9 pm it ran for 5 minutes then off for almost 1 hour. We keep our stat at 78 and 79 degrees. That is one of the reasons why the installer said it was coming on for such a short time and it was satisfying the stat was it only had to cool to barley below outside temp. Humidity is great in the house.

[beenthere]

If your satisfied, then ok.

If my A/C runs for less then 10 minutes when its 75 outside, something is wrong.

[rickytz7111]

Beenthere,

I wouldn't say that i'm satisfied. I just want my system to run like it's suppose to. The installer is telling me that everything is fine with the system. I'm sure that he doesn't want to have to take this one out and put a 4 ton in the house. If my outdoor temp was 75 degrees my ac system wouldn't come on at all. That is what the temp was here last night and it never came on. What do you keep your stat set at? I keep mine at 78-79 degrees.

[beenthere]

72. And the other day when it was 69 degrees outside, it kicked on and ran for more then 5 minutes.

[arc8]

Defintely lower than 78 degrees!

Maybe your stat is off: either it's old or a cheap stat!

Short cycles are not good, no matter what; it could be your stat!

[rickytz7111]

I ordered a new stat and it will be here next week. Would you guys recommend me to get another load calc done? If I do require a 3.5 ton how should I approach the installers to let them know that I want it changed out? Thanks

[beenthere]

Talking to the owner is about the only way.

Might want to contact screen name "dan sw fl". If you can send him the details of your house he can do teh load cacl for you. Don't know what his fee is.
I believe he's an ME.