mitsubishi or heat pump

[yeldogt]

Before I had any idea about hvac and construction and general, I was getting my hvac system done and was offered mini-splits but declined because I didn't want the unit visible. I think most of the american population feels the same and hvac contractors probably hear the same response over and over.

Now that I've installed and operated several mini-splits, a lot of the modern ones that have full front covers, and hidden digital displays, are really not bad at all. They actually give the living space a hi-tech kind of look.

In a perfect world they would be invisible. I agree - In a more modern house or one with tall ceilings they disappear. I don't notice them in my house with cathedral ceilings. They are most noticable from an angle where the depth becames noticable in a traditional setting.

I did two Cassesets -- and think they are a great solution for many large second floor bedrooms. In my case I did keep all four outlets -- but they can be placed where three are used.

The ducted and the new air handler models are another solution -- although they don't have the same control ability. The best wall units have room sensors -- humidity control -- fast recovery mode and the ability to move the air around a room ... mine even will "see" you and will direct air at you or keep it away from you.

They do an unbelievable job at removing humidity -- but so do the newest VS split systems ...

 

[dsimatt]

Too many rooms ! Kitchen, dining room, living room, family room, 3 or 4 bedrooms, 2+ bath. The price would be very high to put an air handler in each room. Running the tubing is easier in a new build, but you would have to build chases to run the tubing.

Good point, also the layout has a lot to do with how well they would work to....I guess when you are the making a brochure its nice putting one in every room, having to buy them not so much.

I think on a new build they could be used as a supplement in certain areas of the house, but they shine the most in houses that running ducting is not a option.

I would love to have one in everyroom of my house but the money's not there so probably do one big unit in my main area and use fans to blow it down the hall and maybe in the future add heads into 1 or 2 bedrooms, I know its not the best idea but it should work ok.

 

[dsimatt]

Before I had any idea about hvac and construction and general, I was getting my hvac system done and was offered mini-splits but declined because I didn't want the unit visible. I think most of the american population feels the same and hvac contractors probably hear the same response over and over.

Now that I've installed and operated several mini-splits, a lot of the modern ones that have full front covers, and hidden digital displays, are really not bad at all. They actually give the living space a hi-tech kind of look.

They are coming out with a lot of different options, I would like to install the ceiling mounted unit to cool my living/dining and kitchen area but no one local recommends doing that and steers towards the wall mounts.

I agree with the perception people have of them and is something i'm concerned about being that this isn't a forever house but they seem to be the best choice for our needs.

 

[kwschumm]

I'd like to know why you think they are a bad fit in newer houses.

One reason might be aesthetics. We were house shopping and crossed one house off our list because of the intrusive appearance of the indoor mini-split units hanging on the wall. Perhaps if they were more common our eyes would have been used to them.

Turns out we will be building a new house+shop. Will go with a conventional system in the house and mini-split in the shop.

 

[dsimatt]

One reason might be aesthetics. We were house shopping and crossed one house off our list because of the intrusive appearance of the indoor mini-split units hanging on the wall. Perhaps if they were more common our eyes would have been used to them.

Turns out we will be building a new house+shop. Will go with a conventional system in the house and mini-split in the shop.

That's what makes me nervous, not having ac ***** big time and my house is miserable once the heat gets into it so IMO I can deal with it, but will it take away potential buyers.

Mini splits are getting a lot more common, by bil was in Chicago for job training and he saw tons of them in condo's and every loved them but up here we are behind the times.

 

[yeldogt]

Much has to do with the installation -- I was completely convinced when I saw my friends 7 head (now 8) Fujitsu installation. It a big victorian -- they disappear. ..... less noticeable vs the radiators?

They did kitchen/ living room/ sunporch -- three bedrooms upstairs and one in the third floor bedroom / bath. The house is huge .. they added a small head in the dinning room later.

 

[bzinsky]

They are coming out with a lot of different options, I would like to install the ceiling mounted unit to cool my living/dining and kitchen area but no one local recommends doing that and steers towards the wall mounts.

It's because there is a significant reduction in efficiency if you use anything but the standard wall mount unit.

 

[theoldwizard1]

They are coming out with a lot of different options, I would like to install the ceiling mounted unit to cool my living/dining and kitchen area but no one local recommends doing that and steers towards the wall mounts.

Wall mounts are more efficient.

 

[dsimatt]

The one thing they said was more things to go wrong to, you need a condensation pump to get rid of the water and also the fact it would be sitting with 2ft+ of insulation around it would make servicing it a big pita.

 

[theoldwizard1]

One reason might be aesthetics. We were house shopping and crossed one house off our list because of the intrusive appearance of the indoor mini-split units hanging on the wall.

Most companies sell a low mount wall unit. About the same size and shape of and old fashioned radiator. Easily hidden behind furniture.

 

[theoldwizard1]

Mini splits are getting a lot more common, by bil was in Chicago for job training and he saw tons of them in condo's and every loved them but up here we are behind the times.

Mini-splits work well in smaller (total) interior space and less rooms.

Larger interior spaces (bigger than a 2 car garage) will likely need 2 or more air handlers. Very large interior could easily require 6 or more and even 2 compressors.

 

[dsimatt]

Mini-splits work well in smaller (total) interior space and less rooms.

Larger interior spaces (bigger than a 2 car garage) will likely need 2 or more air handlers. Very large interior could easily require 6 or more and even 2 compressors.

That's where I keep getting spun in circles on what these can actually do, my dad care takes a couple places that have just one or two and the people say they cool the house down easy, others online say they're a joke.

My place is a ranch around 1200sgft main level with a pretty open kitchen, dining and living room setup then the usual hall and bedroom setup. I've talked to a few different places and they tell me that 2-3 heads would be ideal but I could get by with one head, it won't be ideal but I cooled my old apt with just one window unit and it did ok. The one guy told me I could use a 24k unit in the main area and might need a fan to push the air into the bedrooms but it should handle it.

I'm getting married at the end of the month and so I can't afford to go all in on a ducted unit which would be a huge pain or a bunch of head units....lets just say without a/c its going to be a really long first summer together.

 

[finn]

We installed a Mitsubishi unit with 3 heads four or five years ago and couldn't be happier. We're a couple of hours farther north than dsimatt and have short, cool summers compared to most of the country, but there are still those hot, humid days that make a/c worthwhile.

A conventional system wasn't in the cards because we didn't want to work around the radiant in floor heat.

The Three heads seem to adequately distribute the air, and we normally only use two heads and don't cool the upstairs, unless we have guests.

The system is also great for heating in the shoulder season, where nights are cold, but the house gets a lot of thermal loading from the sun in daytime due to the angle of the springtime and fall sun.

That said, I'd probably go with a conventional system in new construction, and look seriously at other, more cost effective brands.

I also don't think the systems are suitable for shop installation because of the small filter size compared to a conventional air handler.

 

[theoldwizard1]

We installed a Mitsubishi unit with 3 heads four or five years ago and couldn't be happier. We're a couple of hours farther north than dsimatt and have short, cool summers compared to most of the country, but there are still those hot, humid days that make a/c worthwhile.
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The Three heads seem to adequately distribute the air, and we normally only use two heads and don't cool the upstairs, unless we have guests.

The system is also great for heating in the shoulder season, where nights are cold, but the house gets a lot of thermal loading from the sun in daytime due to the angle of the springtime and fall sun.

Radiant in-floor heat AND mini-splits is a great combination ! Comfortable and fuel cost should be reasonable. Installation costs ...

 

[theoldwizard1]

That's where I keep getting spun in circles on what these can actually do, my dad care takes a couple places that have just one or two and the people say they cool the house down easy, others online say they're a joke.

Calculating heating and cooling loads is a real science. Few places do a good job at it. So many variables ! Insulation, windows, orientation, exterior shade (trees), etc, etc.

... they tell me that 2-3 heads would be ideal but I could get by with one head, it won't be ideal but I cooled my old apt with just one window unit and it did ok. The one guy told me I could use a 24k unit in the main area and might need a fan to push the air into the bedrooms but it should handle it.

I'm getting married at the end of the month and so I can't afford to go all in on a ducted unit which would be a huge pain or a bunch of head units....lets just say without a/c its going to be a really long first summer together.

24K BTUs of heating/cooling, dumped into one area, is going to take a lot of LARGE fans to move it around ! And without an air handler in the master bedroom, it will stay hot every summer. Carefully planned, you could add additional air handlers later.

I always worry about bathrooms, especially in winter. You can do in-floor electric resistance heat with a timer or set back thermostat, but I have no idea how fast a ceramic tile floor would heat up.

 

[bzinsky]

That's where I keep getting spun in circles on what these can actually do, my dad care takes a couple places that have just one or two and the people say they cool the house down easy, others online say they're a joke.

My place is a ranch around 1200sgft main level with a pretty open kitchen, dining and living room setup then the usual hall and bedroom setup. I've talked to a few different places and they tell me that 2-3 heads would be ideal but I could get by with one head, it won't be ideal but I cooled my old apt with just one window unit and it did ok. The one guy told me I could use a 24k unit in the main area and might need a fan to push the air into the bedrooms but it should handle it.

I'm getting married at the end of the month and so I can't afford to go all in on a ducted unit which would be a huge pain or a bunch of head units....lets just say without a/c its going to be a really long first summer together.

Pretty sure it's the installation

I've installed 20 myself and have had 5 installed by contractors.

The 5 installed by 2 different contractors don't seem to work that well.

I've came to the conclusion they are not installing them with enough attention to detail. I asked about using a micron gauge and they both told me nobody uses them in the industry.

Meanwhile the 20 I installed I vacuumed down to 100 microns, pressure tested with nitrogen, etc etc. They all work beautifully.

It was really difficult in the real world to find someone who installs them like your supposed to, like described on garage journal and by the manufacturer. I believe it has a significant effect on output and efficiency.

I could be wrong though as they are installed at various locations and it's possible I just undersized them.

 

[yeldogt]

It's all about BTU's. The units have to be sized for the space. Since almost all mini splits sold in the USA today are VS ... They are able to run all the time. Don't know they are doing anything -- this removes the humidity without overcooling. The reverse is true in the winter -- matching the heat to the space -- not ..on/off ... on/off ... on/off.

Seeing how many are installed -- I think lots of HVAC guys look at them as money makers. Many are not installed with much thought ..... more the attitude .. "lets get this up" and "the route of least resistance"

 

[bzinsky]

It's all about BTU's. The units have to be sized for the space. Since almost all mini splits sold in the USA today are VS ... They are able to run all the time. Don't know they are doing anything -- this removes the humidity without overcooling. The reverse is true in the winter -- matching the heat to the space -- not ..on/off ... on/off ... on/off.

Seeing how many are installed -- I think lots of HVAC guys look at them as money makers. Many are not installed with much thought ..... more the attitude .. "lets get this up" and "the route of least resistance"

I have a theory that the hvac trade becomes so complacent with AC just working or not working that they could care less about efficiency

After 20 years of nobody ever calling them back because it's not efficient enough it's easy to see why they wouldn't care

 

[yeldogt]

I have a theory that the hvac trade becomes so complacent with AC just working or not working that they could care less about efficiency

After 20 years of nobody ever calling them back because it's not efficient enough it's easy to see why they wouldn't care

Agree. As the homeowner -- you don't know what you don't know.

I grew up in a big old house .... it had oil fired multi zoned forced air heat installed around 1950. I grew up knowing it would work ,,, most HVAC guys don't want to do it today. Just put two units in -- both oversized naturally.

Real comfort comes when you are able to always have some hot or cold air being distributed -- unless you neighbor had the same house with a great system ... how would you know.

 

[kwschumm]

Agree. As the homeowner -- you don't know what you don't know.

I grew up in a big old house .... it had oil fired multi zoned forced air heat installed around 1950. I grew up knowing it would work ,,, most HVAC guys don't want to do it today. Just put two units in -- both oversized naturally.

Real comfort comes when you are able to always have some hot or cold air being distributed -- unless you neighbor had the same house with a great system ... how would you know.

That's the truth. In 2000 we built a new home and I paid to have HVAC engineers come out and properly size a 3 zone geothermal system with air balance calculations for each room, duct sizes, lots of returns, soil types, loop length and depth, etc. Gave it to a "certified" WaterFurnace geothermal HVAC contractor who ignored every bit of it. Loop too small, registers in the wrong places and not sized correctly, etc. Duct blaster test failed. That system never worked right. I learned that you had to DIY or keep it simple.

 

[dsimatt]

Calculating heating and cooling loads is a real science. Few places do a good job at it. So many variables ! Insulation, windows, orientation, exterior shade (trees), etc, etc.


24K BTUs of heating/cooling, dumped into one area, is going to take a lot of LARGE fans to move it around ! And without an air handler in the master bedroom, it will stay hot every summer. Carefully planned, you could add additional air handlers later.

I always worry about bathrooms, especially in winter. You can do in-floor electric resistance heat with a timer or set back thermostat, but I have no idea how fast a ceramic tile floor would heat up.

The windows are decent, pretty good tree coverage and the attic has 2 feet of atticat insulation in it, the walls not sure.

I know its not the ideal setup going with just one but right now its the most likely to work with the budget and have decent ac in the house, I would prefer adding central air but with the layout and 1/2 finished basement its going to be a big undertaking. As far as heat i'm not worried because i'm not getting it for that, just for ac and being able to warm up the living area in fall and spring.

The one issue is that this really isn't a long term house and so I can't really go throwing a lot of money into it that we won't get back in 5 years or so, the same time I want to be comfortable in my own home and every summer so far has sucked.