dcsimg

Mini-Split Heat Pump

Here you'll find a wide range of discussions on old-house topics.

Moderators: oldhouse, TinaB, Don M, Schag

Re: Mini-Split Heat Pump

Postby rodpaine on Thu Nov 10, 2011 11:13 am

Huckleberry wrote:Snip... Are they quiet enough to be used in a bedroom?
Huckleberry

Yes, the Mitsubishi is, as it has a very low setting which you really can't hear at a distance of 5-6 feet away. All you notice is the air movement, there is no sound. My link that 'chooseopen' posted (thank you!) shows just how close my two units are in terms of where people are. Visitors to our house the past two summers (both with record breaking heat) can't believe how quiet they actually are, including the outside units. The Mitsubishi products were the most recommended, by all the people I talked to, even though they are perhaps the most expensive. They've certainly saved us money during the summer, allowing us to keep the house at 72 F instead of 78 F and spending a minimum $35/month less than our old window units consumed, at 78 F. I am putting two more in... a cooling/heating unit in the garage and a cooling only in my office above the garage, replacing the current window units. They will be Mitsubishi units.
FWIW,
-Rod
rodpaine
 
Posts: 130
Joined: Thu May 28, 2009 9:41 am
Location: Purcellville, VA

Re: Mini-Split Heat Pump

Postby triguy128 on Thu Nov 10, 2011 5:49 pm

Yup, Mitsubishi and Fujitsu are the tops. Again, their efficiency rating nearly match those of Geothermal in cooling mode.

I think I would have even repaired and upgraded my boiler system if the PO's hadn't already removed it, and just added minisplits.

Keep in mind also that high veloctiy and conventional splits will lose some effceincy in theri ductwork. Especially if mounted in an attic. And the sizing and layotu of hte ductwork will also effect effciency. Few people get the actual delivered ratings. Meaning if a unit is rated for 36k BTU and is supposed to draw 2.5kW. IN reality it probably actually delivering to the conditioned space only 30,000 BTU's or less with the same power consumption. 8-10% duct leakage is considered "typical".

A mini split will deliver the rated capacity and efficiency, since there's no ductowkr. So long as you keep the coils cleaned and unit serviced regularly.... same as any refrigeration system.
1925 Neo-Classical

Previous home - 1968 single story Ranch/Colonial, 1200sqft - 11 windows
Current home - 1925 2 story Beaux Arts Neo-classical overlooking the Mississippi River, 3200sqft - 48 Windows
triguy128
 
Posts: 708
Joined: Mon Sep 12, 2011 9:41 pm
Location: Keokuk, Iowa

Re: Mini-Split Heat Pump

Postby Huckleberry on Sat Nov 12, 2011 8:37 pm

Thanks all for the great information. Doing the install myself is tempting. Various YT videos make it look pretty simple. one last question though. I have read that the compressor can be installed on a roof. Do you all believe that it can, in terms of weight and vibration?

Thanks, again,

Huckleberry
Huckleberry
 
Posts: 59
Joined: Mon Dec 06, 2010 6:06 pm

Re: Mini-Split Heat Pump

Postby Daniel Meyer on Sat Nov 12, 2011 9:25 pm

Yes it can. They can also be hung on a wall.
CUAgain,
Daniel Meyer
Author. Adventurer. Electrician. Cat God.
http://theoldvictorian.com
http://lifeisaroad.com
Image
Daniel Meyer
 
Posts: 1236
Joined: Tue Dec 09, 2008 12:04 am
Location: Texas

Re: Mini-Split Heat Pump

Postby Igloochic on Sat Nov 12, 2011 10:04 pm

We are in the final stages of install of a mini-split system. We have two units...one is 48,000 btu (handles 8 zones) and the other is 36,000 (six zones). The system is Mitusubishi, which we thought was the best out there (at least for us). We have a mix of equiptment which was chosen with the idea of being able to "hide" the system to keep the house's period feel. We have three types of heaters. The ones which mount on a wall, which we have hidden in soffits in the basement level and the two that are in bedrooms in the family area are hidden in custom built window pelmets. They are basically silent IMO (you can hear a rush of air when it feels the occasional need to spit out extra heat but that's fairly rare and still really quiet). Then we have units that are boxes people would install in metal boxes on the floor (which could be hidden like a water based heat thingie...ummm what are those called? The pretty iron ones LOL) but because we never had hot water heat in this home we decided to hide them in modified furniture. The master suite has one that is hidden in a tall secretary. A drawer is removed and deep gold metal screening fills the gap where the air flows out. Beneeth the piece (which is on legs) they are making a screen to hide the part you can see on the floor. (We took them out of their big metal box housing so they would fit which was done by the installer and is safe). The other similar unit is in an amoire. I will say this about those two units...they are powerful and we keep them at the lowest setting otherwise the rooms get too hot. But those rooms are going to get much larger with the restoration so we knew this going into it.

The main floors are heated by units which are hung on the ceiling of the basement and ducted to boxes we cut in the floor above. From the main floor all you see is a pretty floor register. The pieces are all hidden in the soffits down below so you don't see all of the ductwork and the boxes when in the basement.

My son's unit is a wall mounted unit in a room that is about 15x18 ish with ten foot ceilings. It runs on low and keeps his room comfortable, but not too hot. It's basically silent and does not disturb him when sleeping, nor does the air blow so hard it bothers him.

The part we are having done now is all about hiding the units (all that soffit stuff as well as building the window pelmets). The units are fully operational and they work very well, very quietly, and make this drafty old place finally comfortable. We anticipate they'll be even better when we finish the restoration and all of the windows have been rebuilt etc. I love being able to change the heat on my ipad :) or phone or computer. Very convenient verses having a thermostat in each room (ugly) or having to go down to the main system to make changes.

We anticipate the pay out to take about 70 years :lol: and no that's probably not an exageration....the system is very expensive....but so far we think it's a great improvement to the old box.
The James House - 1889 "Modern" Queen Anne
Image
Igloochic
 
Posts: 629
Joined: Tue Sep 29, 2009 7:16 pm

Re: Mini-Split Heat Pump

Postby triguy128 on Sun Nov 13, 2011 10:01 am

It's not always about energy savings. You have to be comfortable. variable sped ands 2 stage equipment is as much abotu comfort than energy savings.

I would never put a unit on the roof, unless there were no other options. Not ideal for regular cleaning and servicing. The roof gets hot, hot air + air cooled condenser = lower efficiency. I also think it looks like s***... and scream "hack job".

Ideally you want the outdoor unit on the shaded side of the house, or even better, where it will be shaded by trees in the summer but get sun exposure in winter.
1925 Neo-Classical

Previous home - 1968 single story Ranch/Colonial, 1200sqft - 11 windows
Current home - 1925 2 story Beaux Arts Neo-classical overlooking the Mississippi River, 3200sqft - 48 Windows
triguy128
 
Posts: 708
Joined: Mon Sep 12, 2011 9:41 pm
Location: Keokuk, Iowa

Re: Mini-Split Heat Pump

Postby Igloochic on Sun Nov 13, 2011 1:04 pm

:) Yes ours is definately about being comfortable. In addition we have the added benefit of our basement (which is a daylight space with 1 1/2 thick brick walls) is no longer musty smelling. Since that's our main living space (family) it's nice to not walk down and catch that wiff of damp must. Even heat in all of the rooms is the key.

We put one unit behind our house (between it and the gardeners cottage which also has a unit) and tucked it up in a nook in our fence. We will be building the fence around it to sort of hide it a bit (it's a very tall unit so total hiding isn't possible). The other is under our front porch which is an ideal location because it can breath easily and it's easy access (you can walk in there). For the one outside though I have to figure out what to plant in front of it (not right up next to it of course). It blows out some COLD air :)
The James House - 1889 "Modern" Queen Anne
Image
Igloochic
 
Posts: 629
Joined: Tue Sep 29, 2009 7:16 pm

Re: Mini-Split Heat Pump

Postby Huckleberry on Sun Nov 13, 2011 9:04 pm

FWIW, the roof I'm thinking of is a near flat metal shed roof on the West side, somewhat shaded and real easy to reach (I'm out there two-three times a year cleaning gutters). It's about 20-30 feet from the rooms I'm planning to condition. Piping and so on would be much less obtrusive than if I had to run it to the ground.

Huckleberry
Huckleberry
 
Posts: 59
Joined: Mon Dec 06, 2010 6:06 pm

Re: Mini-Split Heat Pump

Postby triguy128 on Tue Nov 15, 2011 12:31 pm

Huckleberry wrote:FWIW, the roof I'm thinking of is a near flat metal shed roof on the West side, somewhat shaded and real easy to reach (I'm out there two-three times a year cleaning gutters). It's about 20-30 feet from the rooms I'm planning to condition. Piping and so on would be much less obtrusive than if I had to run it to the ground.

Huckleberry



That's not bad then. I'd mounti on some sort of roof supprots and use rubber isolation pads otherwise it might vibrate that roof structure and be annoying from the inside... especilly if it pick up some ice and gets out of balance in winter for a while.
1925 Neo-Classical

Previous home - 1968 single story Ranch/Colonial, 1200sqft - 11 windows
Current home - 1925 2 story Beaux Arts Neo-classical overlooking the Mississippi River, 3200sqft - 48 Windows
triguy128
 
Posts: 708
Joined: Mon Sep 12, 2011 9:41 pm
Location: Keokuk, Iowa

Re: Mini-Split Heat Pump

Postby dyte213 on Sat Apr 20, 2013 3:09 am

I highly recommend sticking with the big guys on ductless mini splits. Fujitsu, Daikin, Mitsubishi are all really good. There is a second tier of providers such as LG, which is ok, and a ton of knock offs that I would stay away from.
dyte213
 
Posts: 1
Joined: Sat Apr 20, 2013 3:07 am

PreviousNext

Return to General Discussions Forum

Who is online

Users browsing this forum: No registered users and 1 guest