When does a package unit make sense - curiocity question

[Citation]

A recent thread about DIY installs got me thinking, why are package HVAC units common in some areas but not others?

Most homes I've lived in have had what to me is a traditional home AC unit, the force air, split system. When I lived in Tennessee my house had a package HVAC unit. Prior to that home I don't think I had ever even heard of such a think (not that I was looking). For those, like me, who weren't familiar with package units, they are an all in one HVAC system where all the mechanical parts are in one box on the side of the house. So rather than having an air handler in your basement or hall closet, the air is actually ducted outside your house into the HVAC system then pushed back in to the various vents in the home.

When discussing possibly replacing the HVACs in that house a friend suggested a DIY install noting that the biggest issue was positioning what is a very large box next to your house. After that it's connect power (and gas in my case) but there is no messing with refrigerant lines. While I considered this, in the end I was able to fix my old system to keep it running until I sold the home (as far as I can tell it was running properly at the time of the sale).

It seems like a horrid idea to pull all my warm air outside to heat it up and placement of the package unit seems less flexible since its very big and must be connected to the house via a housing. Still, the system was really quiet since the blower fan was in the back yard vs hall closet. It also seemed like it should be rather reliable since all the mechanicals are factory assembled. No worry about a commissioning the AC lines on site, no worries about running a proper flue for the gas heat. Still, older homes in Tennessee is about the only place I recall seeing these things. I don't recall seeing them in Atlanta (well my house there didn't have one so obviously no one in the city could have had one...) and I don't think I've seen one in Michigan either. When/where do they make sense? Are they only common on single floor homes with crawl spaces?

 

[Chapter21]

I suppose they only work with certain types of houses...in some parts of the country forced air isn't the most common and other parts building on a slab with no crawl space is common. Probably not very good in extreme climates. Here in NC they are pretty common, but they do often stick out somewhere weird as a retrofit to an old house.

I wouldn't want one on my house but I would totally use one on one of my rentals. Seems like a good option for trailers and people love trailers out here!

 

[toyotadriver]

They are ideal for houses that have no place to put the air handler. Usually small houses. As a retrofit they make sense. As a new build they make no sense.

 

[karoc]

Package units has their places such as for manufacturer homes. Package units can be setup to discharge out side or on bottom.Number post here on GJ I think package units is lot better than these mini splits.Another unit that is similar to package units is Wall mount units,which as name implies it mounts on wall.But they are about 6’ long and about 3’ wide, get them in several different sizes. Supply is at top and return is down lower which you can install grills right there or run duct length of shop.

 

[Max78]

I just installed one on my moms house. Its a mfg house. It's an older R22 3 ton unit, it works good and was $200.

They make sense for retrofits, I.E. Replacing a swamp cooler with AC and no room for a handler in the house. Or your house is just too small. Maybe for something like cooling a large shop where you don't want an air handler in the area, that was what I was going to originally use it for.

I wouldn't want to use it on a new build, efficiency doesn't makes sense to me. You have to run the cooled air through ducting before it enters the house and the best stuff I could find was R9. Your coil and everything is siting outside where it will get heat soaked when off. Then you have the people that don't know how to install the ducting correctly and kink the ducting and compress the insulation, further hindering efficiency.

 

[Chapter21]

I wouldn't want to use it on a new build, efficiency doesn't makes sense to me. You have to run the cooled air through ducting before it enters the house and the best stuff I could find was R9. Your coil and everything is siting outside where it will get heat soaked when off. Then you have the people that don't know how to install the ducting correctly and kink the ducting and compress the insulation, further hindering efficiency.

It's amazing how many I see around here with absolutely no insulation at all. A lot of these same units burn propane for heat when they could just be a heat pump for about 1/3 the running cost. It hurts my brain.

It would definitely make for a nice shop cooler if you can find a cheap used one.

 

[metlmunchr]

Package units make a lot of sense for single story new houses on level lots with low crawl spaces. With run of the mill houses selling for $150 to $400 per sq ft, depending on location, who would want to give up 25 sq ft that costs $3750 to $10K to have a furnace or air handler in a closet within the house? Or the alternative of a horizontal furnace or ahu crammed into a low crawl where the inaccessibility makes for double priced service calls down the road when the tech has to spend half his time wallowing in the dirt rather than working.

Package units are available with gas heat or as heat pumps, or with no heat or electric resistance heat for climates where heat is seldom required. Transient conditions due to temperatures at startup are an inconsequential part of operating costs. Obviously, the supply and return connections need to be insulated and protected from the elements between the unit and house, but that's a matter of competent installation.

I'd agree with Chapter21's comment re heat pumps vs propane heat, and would add that this applies to all residential equipment, split or unitized. Propane prices have to be low to beat the cost of heating with a current heat pump, and given the volatility of propane prices, heating with propane can vary from a bit cheaper than a heat pump to upward of 3X the cost of heat pump operation. Of course, this only applies to areas where winter temperatures are mostly in the range where a heat pump's COP is in the upper ranges.

 

[DL7265]

A recent thread about DIY installs got me thinking, why are package HVAC units common in some areas but not others?

Most homes I've lived in have had what to me is a traditional home AC unit, the force air, split system. When I lived in Tennessee my house had a package HVAC unit. Prior to that home I don't think I had ever even heard of such a think (not that I was looking). For those, like me, who weren't familiar with package units, they are an all in one HVAC system where all the mechanical parts are in one box on the side of the house. So rather than having an air handler in your basement or hall closet, the air is actually ducted outside your house into the HVAC system then pushed back in to the various vents in the home.

When discussing possibly replacing the HVACs in that house a friend suggested a DIY install noting that the biggest issue was positioning what is a very large box next to your house. After that it's connect power (and gas in my case) but there is no messing with refrigerant lines. While I considered this, in the end I was able to fix my old system to keep it running until I sold the home (as far as I can tell it was running properly at the time of the sale).

It seems like a horrid idea to pull all my warm air outside to heat it up and placement of the package unit seems less flexible since its very big and must be connected to the house via a housing. Still, the system was really quiet since the blower fan was in the back yard vs hall closet. It also seemed like it should be rather reliable since all the mechanicals are factory assembled. No worry about a commissioning the AC lines on site, no worries about running a proper flue for the gas heat. Still, older homes in Tennessee is about the only place I recall seeing these things. I don't recall seeing them in Atlanta (well my house there didn't have one so obviously no one in the city could have had one...) and I don't think I've seen one in Michigan either. When/where do they make sense? Are they only common on single floor homes with crawl spaces?

My folks 1000sq ft bungalow has one . Works fantastic with older retro fits with a crawl space . They repurposed the old floor furnace grill as the filter housing . Very efficient .
Only drawbacks , I’ve heard of the heat exchangers rusting / rotting out .


Sent from my iPhone using The Garage Journal mobile app

 

[yeldogt]

They are designed for moderate temp parts of the country --- houses w/o any basement areas for equipment. Same for hotter areas where they are for AC only when they put them on a roof.

In colder parts of the country because the unit is all exposed the efficiency becomes a problem. You can get them with gas heat -- but it's 80% --- so nothing will be damaged if the unit drops under 32. I know people who use them for utility buildings -- the package is a heat-pump and they have a secondary separate propane unit inside

 

[Citation]

The one I had was gas heat. While 80% efficient sounds bad my current system furnace is from the 70s and uses simple up draft. At least the package unit had an inducer fan. Anyway, I appreciate the knowledge dump.

 

[Syberia]

I see them on rooftops all the time here in SoCal. Usually on older houses, so the person who said that they put them there to replace a swamp cooler (which I also see on rooftops frequently) is probably correct.

 

[theoldwizard1]

"Package units" (aka PTAC) were invent for the hotel/motel and apartment industry. They have one claim to fame. They are easy to swap out. In those industries "making the customer happy" in the shortest amount of time is the name of the game.

An apartment complex/motel will have 5 or 10 spares on hand. 1 or 2 unskilled maintenance personal can probably swap one in less than 30 minutes ! The only connection is electrical. Broken units are set aside until a sufficient quantity have accumulated. Then they are carted of to a repair center. A few days later, they returned and ready to go into rotation.

PTACs are notoriously inefficient. Hotels/motels tell the cleaning people to turn them off when they leave. Most apartment complexes have the tenant lay the electric so what do they care.

 

[PoorUB]

PTACs are not packaged units two different animals.

 

[bonneyman]

Package units are more common these days as installers don't have to do welding of the tubes. Everything is internal to the unit, so, fewer warranty calls due to line leaks. Plus, alot of people buying older homes opt to go with a roof unit because older homes typically are short on closet space. Yanking the furnace and coil out of the hallway and putting a package unit on the roof means instant new cubbard or closet. Plus the blower noise is no longer right there in the house. Additionally, efficiencies are usually somewhat higher on package units. (Might not still hold, I haven't compared SEER ratings in many years). With mobile homes, we did quite a few package unit installs out back on the ground to replace the Coleman split system furnace and cond unit for these reasons. (Alot quieter in the main hallway)!
The biggest downside is one has to cut out a return hole in the roof and ceiling, with a potential for water leaks. Power and condensate lines have to be run to the new roof location as well.
Business clients almost always have roof package units to reduce vandalism. Some dumb kid and a broom handle can do alot of damage in a short time along the back side of a strip mall and condensing units sitting all in a row. Plus now people are stealing cond units to strip them for copper.