HVAC experts please chime in

[Babyface Finster 45]

I've got a little 1,000 sq ft, 2 bedroom, one bath shoebox for a house. I was lugging the window A/C units up today and am wondering if there is a better way.

 

The house is a ranch and is heated with hot water baseboards, so no existing ductwork. The window units get the job done, but they are noisy, inefficient, a pain in the a** to move twice a year and leave me with obvious security concerns.

 

I was thinking about either ductless units or a high-velocity mini-duct system. The mini-duct is more attractive as all the rooms could be cooled even with the doors closed. The ductless would probably be the easiest to implement. Otherwise, I'm not sure of the pluses and minuses. I'm pretty sure I'm looking at 220V either way so that's good.

 

If I am lucky, we will be relocating in the next 3-5 years so I'm not looking to dump a ton of money into this place but a reasonable investment for improved efficiency and to escape the other drawback of the window units would be worthwhile.

 

Any info or advice? Relative pricing, operating costs, performance, installation issues, etc. I'm also a little concerned with how to clean 2" ducts.

[hd2000fxdl 422]

Is there a crawl space in the attic??

[Qel Hoth 33]

Any way to install a valve and use the existing piping, but run cold water through it?

[Babyface Finster 45]

Is there a crawl space in the attic??

 

I have a full, unfinished attic.

[Babyface Finster 45]

Any way to install a valve and use the existing piping, but run cold water through it?

 

I'm no expert, but I'm pretty sure this will not work.

[alec.mc 180]

Any way to install a valve and use the existing piping, but run cold water through it?

 

Interesting thought, but it doesn't work like that.

 

 

 

 

Babyface, I'd forget the high velocity systems, especially if you have a ranch with easy access to every room in the house from your attic.

 

Mini splits are o-k if you want to cool certain areas, or just one room. Even leaving all the doors open in your home, it would take damn near forever to pull down to an even temp.

 

Central air is really the way to go if you have a ranch. I have a ranch as well, installed my own central air in about 3-4 days time, working on it after work. Depending on the age of your home, insulation, and other variables you'll prob. need a 2 ton - 2.5 unit ( 24,000 - 30,000 btu ). You'll need to do a Manual J calculation to find out how many BTUs you need to cool your home properly, Bigger is not always better - it will pull down the temp way too quickly, and leave all the humidity in the house. Too small and it will run forever and and ever.

 

I put in a 2.5 ton system last year in my home, doing all the work myself I spent about 3k on everything. Some cut fingers , bunch of curses, and sweating like a pig in the attic it was done. Best money every spent ! ( not to mention, adding huge value to your home when you go to sell, some people wont even consider a house if It doesn't have A/C )

 

If you decide to go this route feel free to ask me any questions, installing central air in a ranch home is relatively easy. I also do commercial hvac maintenance for a living.

 

I also have the proper certifications and equipment for handling refrigerant if you need somebody to add in the refrigerant so it runs properly.

[johna hex 1]

If you have the space in attic or basement then run a split unit with duct work. If you don't then a ductless spilt is good but there is alot of little things you have to do with the system also it's critical charge and it's probably gonna be a 410a unit so it has to be charged liquid. Also the duct less splits you have to run a Lineset to each airhandler.

[Dan 177]

I'm told that homes with hot water heat, they prefer to install an air handler and cooling coil in the attic, along with the proper duct-work. They can then run ceiling mounted vents from the attic into each room, this way there is no destroying sheetrock to run ducts. If you have a 2 floor house it would be more involved, but a ranch it should be much easier.

[alec.mc 180]

I'm told that homes with hot water heat, they prefer to install an air handler and cooling coil in the attic, along with the proper duct-work. They can then run ceiling mounted vents from the attic into each room, this way there is no destroying sheetrock to run ducts. If you have a 2 floor house it would be more involved, but a ranch it should be much easier.

 

Exactly, or in other words ( and my opinion ) If you have hot water baseboard heat, and plan to upgrade your HVAC, do not pull out your baseboard to go with forced hot air. I am a much bigger fan of hot water heat over air.

 

A ranch home is the easiest setup to have for a new install, I doubt you'll get anybody sane to do it now in the summer months ( 200 degree attic ) but if you wait till fall or winter, it'll be much more pleasurable to work up there.

[OnefastNotch 0]

if your attic allowes you to run duct work into the whole house the i would just do that. even if you plan on selling in 3-5 years you are adding more value to your house with a true central air system then if you just put in slim line ac systems in a few rooms. If you hire a HVAC company to do it you will pay top rate right now since it is A/C season already. its best to always get a company to put in AC or even a boiler in between the seasons since there slow.

[dtown223 12]

 

Interesting thought, but it doesn't work like that.

 

 

 

 

Babyface, I'd forget the high velocity systems, especially if you have a ranch with easy access to every room in the house from your attic.

 

Mini splits are o-k if you want to cool certain areas, or just one room. Even leaving all the doors open in your home, it would take damn near forever to pull down to an even temp.

 

Central air is really the way to go if you have a ranch. I have a ranch as well, installed my own central air in about 3-4 days time, working on it after work. Depending on the age of your home, insulation, and other variables you'll prob. need a 2 ton - 2.5 unit ( 12,000 - 30,000 btu ). You'll need to do a Manual J calculation to find out how many BTUs you need to cool your home properly, Bigger is not always better - it will pull down the temp way too quickly, and leave all the humidity in the house. Too small and it will run forever and and ever.

 

I put in a 2.5 ton system last year in my home, doing all the work myself I spent about 3k on everything. Some cut fingers , bunch of curses, and sweating like a pig in the attic it was done. Best money every spent ! ( not to mention, adding huge value to your home when you go to sell, some people wont even consider a house if It doesn't have A/C

^^^^^^^^^^^^^

This is the answer to your question

100% correct information

[heaterbob 53]

not for nothing but why did wait for a/c season to think about installing central air, I have been in the hvac field for 25 years and had my own business for the last 12 every year I give tons of estimates in the fall and over the winter for overhead systems in ranches which by the way are a piece of cake to do. The problem is once it is hot outside your attic can easily reach 140 degrees and it really sucks to work up there. with that being said I personally do not charge extra for the work when the season is upon us.

size of unit is mostly based on square feet if you figure 500 sf for old house and 600 sf for new house you will be very close. if your intrested in pricing send me a pm and of course the is a forum discount, or can take firearms a partial payment.

[djg0770 481]

Minisplits have come quite a ways in the last 10 years. They are exceedingly quiet, you have to put your hand in front of the air outlet to know if they are running or not. Many of the newer minisplits use multiple evaporators (indoor units) with a single condensing unit allowing you to apply cooling where you want it and when you need it. In addition, their efficiencies are in general far higher than your typical attic mounted air handler. Furthermore, by avoiding ductwork in the attic you avoid picking up between 2 and 5 degrees of heat from the attic just from the surface of the ductwork. ANYONE would prefer a multizone system over a single zone system any day and thats what you would get with a minisplit system.

 

That said, the cheapest approach will likely be your attic airhandler. You should expect to be at 500 sq ft per ton of cooling but a Manual J calculation is IMO necessary.

 

Qel Hoth mentioned running cold water in your baseboard. I wouldn't recommend this - but it's a "new" green approach in some regards (google chilled beam technology). At home without the proper controls you will end up with VERY WET floors utilizing this approach.

 

By the way, Heater Bob posted his reply while I was typing my response so you have it now from two sources - 500 sq ft per ton...

[when_shtf 4]

you'll prob. need a 2 ton - 2.5 unit ( 24,000 - 30,000 btu ).

 

Install the air-handler and ducting in the attic space. Cool air falls. Systems that have to pump the cool air up to the house are not as comfortable as a top-down system.

 

A 2.0 to 2.5 ton system is much too big for a 1,000 sq ft ranch. A unit that large will short cycle and only make the house feel cold and clammy. An AC needs to run to scavenge the moisture. My first floor system is 2.5 Ton for 2600 sq ft. The upstairs system is 1.5 ton for 1,600 sq ft.

 

When you do the heat loss/heat gain calculation, it is best to round down. Never round up.

 

Another bit of advice, a 10 to 12 SER is plenty efficient for our climate. More then likely you'll run the system for less then 30-45 days per year. You will never recoup the investment in a 14 SER system. Further, the lower SER units are less prone to failure.

[alec.mc 180]

Install the air-handler and ducting in the attic space. Cool air falls. Systems that have to pump the cool air up to the house are not as comfortable as a top-down system.

 

A 2.0 to 2.5 ton system is much too big for a 1,000 sq ft ranch. A unit that large will short cycle and only make the house feel cold and clammy. An AC needs to run to scavenge the moisture. My first floor system is 2.5 Ton for 2600 sq ft. The upstairs system is 1.5 ton for 1,600 sq ft.

 

When you do the heat loss/heat gain calculation, it is best to round down. Never round up.

 

Another bit of advice, a 10 to 12 SER is plenty efficient for our climate. More then likely you'll run the system for less then 30-45 days per year. You will never recoup the investment in a 14 SER system. Further, the lower SER units are less prone to failure.

 

 

Which may be true, depending on variables. Like already stated, a Manual J will tell you exactly what you need. If you want to go by your 500-600 sq ft per ton, 1000sqft/500=2 = 2tons, The other 6000 btu could be used for a basement he may want to finish, or 3 season porch or something, Was just a guess-ta-ment. His house could be built 70 years ago, or 10 years ago. How well insulated and tight the house is makes a difference, as do window types, how many, which direction your house faces, ceiling height, etc etc.

 

Buy(lease) this program here http://www.hvaccomputer.com/main.asp.

 

once you enter in all your info, it'll give you your Manual J results, and tell you how many total cooling btus you need, how many CFM per room, etc.

[Babyface Finster 45]

If you decide to go this route feel free to ask me any questions, installing central air in a ranch home is relatively easy. I also do commercial hvac maintenance for a living.

 

I also have the proper certifications and equipment for handling refrigerant if you need somebody to add in the refrigerant so it runs properly.

 

Thanks for the offer. I'll be in touch later this year.

[Babyface Finster 45]

not for nothing but why did wait for a/c season to think about installing central air, I have been in the hvac field for 25 years and had my own business for the last 12 every year I give tons of estimates in the fall and over the winter for overhead systems in ranches which by the way are a piece of cake to do. The problem is once it is hot outside your attic can easily reach 140 degrees and it really sucks to work up there. with that being said I personally do not charge extra for the work when the season is upon us.

size of unit is mostly based on square feet if you figure 500 sf for old house and 600 sf for new house you will be very close. if your intrested in pricing send me a pm and of course the is a forum discount, or can take firearms a partial payment.

 

I'm not looking to do this at the moment. This is just the research phase. The widow units are in and they cool the house effectively, I'm just not sure I want to stick with them in the future.

 

Thanks for the info.

[Babyface Finster 45]

Minisplits have come quite a ways in the last 10 years. They are exceedingly quiet, you have to put your hand in front of the air outlet to know if they are running or not. Many of the newer minisplits use multiple evaporators (indoor units) with a single condensing unit allowing you to apply cooling where you want it and when you need it. In addition, their efficiencies are in general far higher than your typical attic mounted air handler. Furthermore, by avoiding ductwork in the attic you avoid picking up between 2 and 5 degrees of heat from the attic just from the surface of the ductwork. ANYONE would prefer a multizone system over a single zone system any day and thats what you would get with a minisplit system.

 

That said, the cheapest approach will likely be your attic airhandler. You should expect to be at 500 sq ft per ton of cooling but a Manual J calculation is IMO necessary.

 

Qel Hoth mentioned running cold water in your baseboard. I wouldn't recommend this - but it's a "new" green approach in some regards (google chilled beam technology). At home without the proper controls you will end up with VERY WET floors utilizing this approach.

 

By the way, Heater Bob posted his reply while I was typing my response so you have it now from two sources - 500 sq ft per ton...

 

I had no idea the mini splits could do multiple zones. Glad I asked this question, there's a lot I need to learn before making a decision. Thanks.

[heaterbob 53]

Install the air-handler and ducting in the attic space. Cool air falls. Systems that have to pump the cool air up to the house are not as comfortable as a top-down system.

 

A 2.0 to 2.5 ton system is much too big for a 1,000 sq ft ranch. A unit that large will short cycle and only make the house feel cold and clammy. An AC needs to run to scavenge the moisture. My first floor system is 2.5 Ton for 2600 sq ft. The upstairs system is 1.5 ton for 1,600 sq ft.

 

When you do the heat loss/heat gain calculation, it is best to round down. Never round up.

 

Another bit of advice, a 10 to 12 SER is plenty efficient for our climate. More then likely you'll run the system for less then 30-45 days per year. You will never recoup the investment in a 14 SER system. Further, the lower SER units are less prone to failure.

 

 

 

13 seer is standard efficiency you cant even buy 10 or 12 seer

[when_shtf 4]

13 seer is standard efficiency you cant even buy 10 or 12 seer

 

That makes sense since its been a while since I was in the market. Still, I would avoid an "up sell" to a more efficient unit.

[alec.mc 180]

That makes sense since its been a while since I was in the market. Still, I would avoid an "up sell" to a more efficient unit.

 

I have a 2.5ton 13 seer in my home, Prior to that I was using 2 window units and an old " in-wall/window " unit that was at least 20 years old..thing was a dinosaur ! My electrical bill is actually cheaper now with the central air. Winning.

[East Brunswick Sportsman 4]

I've got a little 1,000 sq ft, 2 bedroom, one bath shoebox for a house. I was lugging the window A/C units up today and am wondering if there is a better way.

 

The house is a ranch and is heated with hot water baseboards, so no existing ductwork. The window units get the job done, but they are noisy, inefficient, a pain in the a** to move twice a year and leave me with obvious security concerns.

 

I was thinking about either ductless units or a high-velocity mini-duct system. The mini-duct is more attractive as all the rooms could be cooled even with the doors closed. The ductless would probably be the easiest to implement. Otherwise, I'm not sure of the pluses and minuses. I'm pretty sure I'm looking at 220V either way so that's good.

 

If I am lucky, we will be relocating in the next 3-5 years so I'm not looking to dump a ton of money into this place but a reasonable investment for improved efficiency and to escape the other drawback of the window units would be worthwhile.

 

Any info or advice? Relative pricing, operating costs, performance, installation issues, etc. I'm also a little concerned with how to clean 2" ducts.

My advice to you is Call Rich's Plumbing and Heating and A/c they are in East Brunswick. Rich's is a honest and straight up guy. They will not guide you the wrong way. Tell hims Eric's Premier Auto Center recommend him.

[djg0770 481]

Another bit of advice, a 10 to 12 SER is plenty efficient for our climate. More then likely you'll run the system for less then 30-45 days per year. You will never recoup the investment in a 14 SER system. Further, the lower SER units are less prone to failure.

 

Mitsubishi has minisplits between 15 and 21 SEER. By your advice he should ignore Mitsubishi entirely. Don't buy that Jetta TDI either, that diesel costs more. Stupid wasteful Americans. Use less energy pay less money, period. Electricity costs continue to rise and the current Precedent (it's a pun) has indicated that he needs energy to rise to make green technologies "affordable". In general you can qualify for utility rebates that will make your "upcharge" negligible by going with a more efficient unit.

 

Don't buy that 98% efficient boiler either as it's only 98% efficient when the return water temperature is really cold - just keep buying that (barely) 80% efficient cast iron monster despite the fact that the 98% masterpiece manages to make a minimum of 87% at most operating conditions.

 

Don't switch from oil to gas either as oil has more btu's in a gallon than gas has btu's in a therm. Nevermind that gas is 1/2 the cost of oil, that's irrelevant.

[when_shtf 4]

Yes, you seem to understand my point.

[civictuner04 6]

mitsubishi has mini splits up 2 26 seer and if your gonna tell me thats the same as 14.5 seer your nuts. and the lower the seer the less problems is bs again. i love going up against people like you in the field im almost double and i win 65 percent of the time. if its installed right whether its pos goodman equpiment or lennox signature product 2 stage dual fuel with zone its going to work worry free. when hacks reuse everything run wrong size vent piping and linesets thats when you screw the customer. 95% of what we install is 98% modulating heating with 21 seer 2 stage ac and i get on average 3 referalls on every install. i know how to make people happy because i know what works........