I'm thinking of installing a mini split A/C for the bedroom...

Discussion in 'HVAC' started by havasu, Mar 19, 2016.

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  1. Mar 25, 2016 #21

    havasu

    havasu

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    My A/C installer is trying to convince me that these are a waste of money. He just installed a 5 ton HE A/C system, and wants me to use it for one season before deciding on the mini split. Hmm, maybe he is correct?
     
  2. Mar 25, 2016 #22

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    I guess it can't hurt to try it for a year.

    My house is 2700 sq ft, I have two Trane ~ 20 year old units. One for the bedroom side of the house and the second for the other half of the house. Two bedrooms are upstairs and in the summer, neither one of those units will recover and turn off in the after noon hours. I think they are both roughly 2.5 ton units. I would love someone to tell me if two new high seer units would save me some money on electric and be able to cycle on and off now and then.
     
  3. Mar 26, 2016 #23

    WyrTwister

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    Your installer may have never dealt with a MS & " afraid " of them ?

    Or he may see himself making more money installing " conventional " systems ?

    How much is he asking to install a 2-1/2 ton system ?

    Gas heat or electric ?

    Heat pump or straight A/C ?

    What SEER ?

    God bless
    Wyr
     
  4. Mar 26, 2016 #24

    oldognewtrick

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    Efficiency of the newer units are a lot better than your old ones. Another issue to consider is insulation/ventilation. If you can block radiant energy from transmitting down, your units will have less work to do. What type roof/insulation/venting system do you have on your home?
     
  5. Mar 26, 2016 #25

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    The insulation in the attic is blown in. The small particles, don't know what they are called but it is in good shape. I am not fluent in venting, but I have the ~screen under the edge of the roof and one of those 10" turbines on the roof in two places. Unfortunately the Mistletoe has taken out about 8 big Oak trees that used to shade the house. My Magnolias and Maples are far too small to give any shade for years to come. If I could afford it, I would have new windows put in. Some that are not only double pane, but tinted as well. That would probably be a large savings too.
     
  6. Mar 26, 2016 #26

    oldognewtrick

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    You will need to measure the depth of the insulation and determine "R" value. Add if necessary to bring up to recommended. I would recommend removing the turbine vents and installing ridge vent if you have sufficent ridge run to support it. Make sure the soffit vents are not blocked with insulation.
     
  7. Mar 27, 2016 #27

    WyrTwister

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    I may be wrong , but I think you can buy sheets or rolls of " tint plastic " and DIY it to your existing window glass ?

    Do you have storm windows over your primary windows ?

    Back to your existing central air systems . No idea what their SEER rating is , but maybe 10 - 13 ?

    I have read that for central systems , about 16 SEER is the point of diminishing return .

    The MS we installed in the living room is a bottom of the line 13 SEER unit . The one we installed last year , in our bedroom is a 16 SEER . They get pricey , but MS's are available in the high 20's in SEER rating .

    Plus there is no loss in the duct work .

    Of course , better insulation will benefit you , no matter what else you do .

    God bless
    Wyr
     
  8. Mar 27, 2016 #28

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    Good suggestions guys. I'll check the insulation in the attic. It can't cost that much to have more blown in. The down stairs turbine roof has plenty of ridge, but the two story attic comes to a peak. Not sure how you could change that.
    What's a good rule of thumb for inches in the attic?
     
  9. May 28, 2016 #29

    AtticFoil

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    10 years ago, I worked for Daikin (now the worlds larges AC Manufacturer) when they were getting going in the US market. I used to do many lunch-an-learns on the benefits of mini-splits. There is nothing better for comfort and efficiency! And, they are relatively easy to install since the power to the indoor unit comes FROM the outdoor unit next to the line set. The key is to make sure you are using an inverter type unit. They have true variable compressors that will ramp up/down depending on the load. This means dead-on set point and great dehumidification. When I built my home I did the whole house in both ducted and ductless units. The one in the master is amazing. We can close the door, and keep it as cool as we want, no hot-sweating/cold-freezing cycles! I'd recommend Daikin, Mitsubishi, Fujitsu, LG, Sanyo products.
     
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