Posted: 6/27/2016 12:22:06 PM EDT
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Have a few questions on ductless v central air system.
House is older. Split level with a full basement. Appx 4k total square feet. Looking at options to reasonably get a primary heating and cooling system for the full house. According to calculations I can find for sizing one of these, it appears like a 10 total ton system would be needed for the entire house. The only one I know of that large are commercial units, or two smaller 5 tons. Questions: Is there a rough idea on what it would cost on a full HVAC system (need ducts, units, furnaces/blowers, wiring etc.) for this size house? I was looking into ductless systems. What size of these would I need? Any suggested brands to look into/get? I see several models with 5 or so cooling zone heads. Would that be a good idea? Any rough idea on installed price, and what prices systems should be running at? |
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Personally I would not suggest ductless for a house that size. If there is no other option, I can understand, but have you confirmed you simply cannot run ductwork and you cannot find space to put a furnace or air handler? You need to have a competent a/c tech come out and perform a manual J and D to get an idea of what sort of system you will need. Since you'll need 2 systems, plus the ductwork, yes it's gonna be pricey. I would say $15,000 might be at the bottom, but a contractor will be able to quote you properly. |
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Quoted:
Personally I would not suggest ductless for a house that size. If there is no other option, I can understand, but have you confirmed you simply cannot run ductwork and you cannot find space to put a furnace or air handler? You need to have a competent a/c tech come out and perform a manual J and D to get an idea of what sort of system you will need. Since you'll need 2 systems, plus the ductwork, yes it's gonna be pricey. I would say $15,000 might be at the bottom, but a contractor will be able to quote you properly. Can you ball park it? I assumed $15k minimum, but likely heading towards $30k. The ductwork can be ran if necessary. Is there a reason in particular you are gun shy on a ductless? I know no one with such a system or ever seen one in real life, so unfortunately .am blind there. Thanks a lot of the reply. |
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Daikin and Mitsubishi make 8 zone unit that are 4 tons each.
I do HVAC for a living and I put the mini splits in my fathers house and he loves them. Mini splits is all I would recommend at this point unless you already have duct work then I would tell you to get Trane inverter driven unit with heat pump and gas multi speed indoor fan. Why would you pay to condition 4k of space when you are only in maybe 1k of it most of the time. Plus I like to sleep in a meat locker so you cant do that with a unit cooling half your house. Daikin and Mitsubishi also have 10- 12 years parts warranty If you are in MA or NH send me a PM |
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I love my Daikin multi split. It's a 3mx and I have 2 systems ran off it currently. 18k in living room and 7k in bedroom. 1000sqft. Does it fine. Not an open floor plan either. It's all how the air blows. Heat pump too. Works fucking awesome.
I was going to do central but the ductwork and future service work would be terrible. My attic is trussed |
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Quoted:
I love my Daikin multi split. It's a 3mx and I have 2 systems ran off it currently. 18k in living room and 7k in bedroom. 1000sqft. Does it fine. Not an open floor plan either. It's all how the air blows. Heat pump too. Works fucking awesome. I was going to do central but the ductwork and future service work would be terrible. My attic is trussed Not sure what 3mx is. I assume you mean 2 of the "heads" which I reckon are called condensor assemblies/" Thanks for the reply and info. Harder than hens teeth to find out real world experience with these, other than simplicity of install. |
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3mx(condenser) can handle 3 evaporators (indoor wall units) with one condensing unit outside. A 2mx handle 2 evaps. They make a 4mx as well. The condensers are what the call a multi zone. and they make an 8 zone multi split condenser as well. On the 3mxs I have (3 zone) I got that due to the btu's (24000, or a "2 ton" so I can run an 18000 btu evap and a 7000 btu evap and yes you can go over the rated btu's of the condenser. Daikin has a chart that shows you combinations of indoor units that you can use in conjunction with a multi zone condenser) Here is what shows you. Go to page 19. Page 19 starts with a 2mxs18nmvju (18000 btu 2 zone heat pump condenser) and follow to the next pages it will go to the 3mx to the 4mx and it shows you what btu indoor units you can use with the multi split condenser)
Here is a link for their single zone, multi, and the whole house (8zone) just to familiarize yourself with what is offered before you choose what to install. The installer will know all this as well, I'm just telling you what's out there and what you can do. Don't do it yourself because you don't want to oversize things. Have them figure out heatloss and gain to find how many btu's you need per room. |
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Quoted:
3mx(condenser) can handle 3 evaporators (indoor wall units) with one condensing unit outside. A 2mx handle 2 evaps. They make a 4mx as well. The condensers are what the call a multi zone. and they make an 8 zone multi split condenser as well. On the 3mxs I have (3 zone) I got that due to the btu's (24000, or a "2 ton" so I can run an 18000 btu evap and a 7000 btu evap and yes you can go over the rated btu's of the condenser. Daikin has a chart that shows you combinations of indoor units that you can use in conjunction with a multi zone condenser) Here is what shows you. Go to page 19. Page 19 starts with a 2mxs18nmvju (18000 btu 2 zone heat pump condenser) and follow to the next pages it will go to the 3mx to the 4mx and it shows you what btu indoor units you can use with the multi split condenser) Here is a link for their single zone, multi, and the whole house (8zone) just to familiarize yourself with what is offered before you choose what to install. The installer will know all this as well, I'm just telling you what's out there and what you can do. Don't do it yourself because you don't want to oversize things. Have them figure out heatloss and gain to find how many btu's you need per room. Thanks I really appreciate the detailed info. Really hard to find information on these. Almost like industry doesn't want the info out there. 
I really appreciate the links and will check it out. |
| Look at the Trane or American Standard variable speed systems. With their zoning systems you can install up to eight zones. I have a three zone Mitsubishi system in my house. Two floor units for the bedrooms upstairs and an air handler for the main floor. If you go this route I would suggest installing separate systems for each level. All the air handlers need to be set to heat or cool at the same time and if it's cool downstairs and warm upstairs it can be frustrating sometimes. Using a ductless system for 4k sq. ft. is going to be expensive, probably much more than the Trane or American Standard variable speed system. |