Larger sized A/c' don't remove more moisture. They tend to cool the house down too quick.
Beenthere is correct oversized will not provide better Humidity control just opposite. The system will short cycle and not keep the humidity in check. Also I need to correct my statement, the XB 13-14 heat pump does come with a sound blanket.
Just make sure the company does a load cal. An proper size your system. Depending on your budget the XR13-15 offer a better color option if that matters to you for the $? I personal have the Trane XR15 In my home and works great, the color is cleaner and I pay $85.00 Electric bills.
The same can be achieved by a XB 14 with the right air handler/furnace but I chose the XR15 for the looks and Seer rating back in 2009!
+1, that contractor is wrong, unless... they set-up equipment incorrectly and set the blower speed too high on smaller units hurting their latent capacity.
I changed out a 3.5ton for a 2 ton in my own home and humidity levels went from struggling to stay under 55% RH and overcooling by 2-3F to dehumidify, to now it's 42-48%RH, no overcooling, completely silent and much more efficient (by more than the SEER rating alone would predict).
thank-you everybody, I've decided to go with the XR, but I'm not 100% sure what ton, I've been referred to the 3.5 but with everyone's help here, I'm going to probably go down to between 2.5 to 3 ton, I'm just not sure yet, do ya'll know if a half ton makes a big difference? My goal is to have the most efficient unit that doesn't run all the time and keeps my electric bill down. Thanks again you guys have been a big help!
Don't go too small or your unit's life span will be cut short. the perfect unit is that one that runs constantly on the hottest day and is still able to cool your house. A oversized unit cycles on for short periods and off frequently and that actually wastes more electricity.
Originally Posted by georgiajill
If you like your contractor... tell them to do a Manual J load calculation. No need to guess... science has the answers.
You can call me Sam
It should be a crime to be a mechanical engineer in San Diego
Summer Design Temperature: 83 F Dry Bulb ~ 69 F Wet Bulb (California Climate Zone 7
Just make sure that whenever a load is done on the home that the contractor knows what he is doing when inputting the date. Most contractors still just use the same input of insulation in the fields. Let me explain with foam insulation you run into these. The walls, ceiling etc... When foam is sprayed gives you the same r-value so as roof line with 5-6 inchs of foam will be rated a r-30-38 and 2/4 walls with 3-4 inches of foam are rated at r-13-15.
Originally Posted by georgiajill
This from my experience is where some contractors make a mistake and count the r-valve as the same as regular insulation which is correct but the infiltration amounts into the home is greatly reduced and depending on how your ductwork is run and which foam system you use, your ductwork and equipment would be considered to be in semi condition space.
To make it simple, you need someone who is not going to fudge the #'s just to get load where they think it should be. Example I can make a 1500 square foot home look as it needs 4-5 ton system. Most HVAC contractors are scared that they will have a system installed that will be to
Small and not cool properly. So they use rule of thumb or input date to show certain things in the home that will make the load look much worst then it is. I can't tell you how many times I have this but if I had a dollar for everyone, I could retire!
Again you need someone to do a proper load cal. With the right input info. A contractor that knows what he is doing in this area want lose any sleep over installed a proper sized system as the software now is so easy to use just plug it in and you can have a load in 10-15 mins. I still remember when I use to have to so by hand and the time it took. Now it is so easy in floors me that people still don't use it!!!
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Last edited by jpsmith1cm; 07-27-2012 at 06:24 PM.
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