HVAC Experts, a question or two.

[Rams]

A friend and I were working on his bike in my shop/garage recently and even though I had a couple of fans turning full blast, it was still damn hot.   He really likes my garage, lift and tools but asked me why I hadn't put an airconditioner in the garage.

While I do have windows that I could slide a window A/C unit into, I'm wondering if I decided to actually install A/C with vents and an outside unit, would it be possible or reasonable to stack that unit on an elevated platform above the other home units?

That may sound a bit silly but there's a reason for putting it up above the other units.   Closeness to the property line being one and it's location to other electrical components with less wiring considerations.   I'm sure I'd need a pan to catch and drain off condensation to avoid it being drained onto the already established home units.   I've seen A/C units under decks before, I wouldn't like that and who really wants hot air to be blowing up from below if you're out on your deck.

Just curious, it may never happen and the possibility of a window unit is much more likely and much cheaper.  

Rams

[f6john]

If I had your money, I’d have to go with a mini split unit. If I were going to put air in my garage which is much smaller than yours, I’d still go with a mini split, but I would have to borrow the money from you.

[Rams]

If I had your money, I’d have to go with a mini split unit. If I were going to put air in my garage which is much smaller than yours, I’d still go with a mini split, but I would have to borrow the money from you.

Well, I'm more than willing to spllt my allowance with ya if that'll help.   But, you know that half of nothing is still nothing.

You having seen my garage and know it's size, I don't know squat about mini-split A/Cs but, would that be more economical that one large window unit (or two smaller units) to operate?

Both of my garage doors are the insulated versions but, I don't know that will help all that much.

Edited:  Does a mini-split require an outside unit or any other construction/destruction of the walls/ceiling?  If so, a window unit or two would be one heck of a lot easier.


Rams

[carolinarider09]

While I did get my HVAC "cert" 15 years ago, I only got it so I could buy freon for my 1996 Ford Explorer.

Having said that, one of the issues with any HVAC unit is un restricted air flow to the outside unit (condenser I believe is the correct term).   That is where the freon is cooled so that it can be used, again, to cool the air in the evaporator (where the air to be cooled is circulated).  

So, while you could stack the "condensers" if the bottom one blows air up to the upper one, you have hot air trying to cool the freon (well maybe its not really freon any longer).   It will not cool as well.  

That is the biggest issue I would see with stacking.  

Regarding the mini-split, we purchased one for our enclosed porch.  It does its job but also has a separate "condenser" unit.  The only issue I have with the mini split is that, in my case, the evaporate where the air is heated or cooled is mounted above the door way to the porch.  Good for cooling since cool air is more dense and falls to the floor level. Seemingly bad for hot air since hot air is not as dense as cold air and will simply rise up from the mini-split.  The mini-splits are flow out does have a "thing" that is used to direct the air out either upwards or downwards.  

Again, I think the issue with stacking would affect the unit's efficiency.  

[scooperhsd]

mini-split - no arguement. Higher SEER, capacity for bigger space, and most of them are heat pumps, so you can also have heat in the winter. When we want to start using the attic as living space - we will be going with a 3 ton minisplit for that space.

I don't know anything about stacking condenser units, but it seems to me to be a bad idea. But - the minisplit will likely have a smaller condenser than a conventional heatpump / airconditioner.

[Rams]

While no decision has been made, the above information makes sense to me.   Thinking I'll start looking at window units for the garage.   For information purposes, my garage is 30 X 38.   Decided when we were expanding the house that if I was going to have a garage, I wanted it big enough to move around in.
Thanks for the feedback.

Rams

[carolinarider09]

 

[Jess from VA]

I am no expert.  I would get a window unit, and put in a ceiling fan or two for circulation.

I put a ceiling fan in my 10 X 12 bike shed.  No cooling but it makes a big difference in heat, if I'm not out there too long.

Does the garage have a ridge (roof) vent? 

[Rams]

I am no expert.  I would get a window unit, and put in a ceiling fan or two for circulation.

I put a ceiling fan in my 10 X 12 bike shed.  No cooling but it makes a big difference in heat, if I'm not out there too long.

Does the garage have a ridge (roof) vent? 

Currently thinking either one large window unit (or two smaller units) and some wall mounted oscillating fans.   I don't want to give up the headspace due to my lift and the two garage door openers.  Could put up a single Big Ass Fan in one part of the garage (not above the lift) but those are pretty dang expensive.

Thanks for the suggestions.

Rams

[cookiedough]

how much time u spend in your HUGE garage?  Me being cheap and would work, is buy one of these I got for my daughter's house at Costco on sale for 300 bucks and be done with it.  Her house is 1000 sq. ft and cools it down fine except the far other end where bathroom and kitchen is, but surely helps in 90+ degree heat.  Am sure your man cave HUGE garage is insulated, so this would work fine and can be moved around.  Has a dual hose that needs to be vented out a window and also can be used for HEAT in the winter. 

https://www.costco.com/hisense-smart-sacc-8%2c000-btu-dual-hose-portable-air-conditioner-with-heat-pump.product.4000106320.html

300 is surely cheaper than pretty much anything else besides a window unit AC and this can be moved around in your garage so closer to where you need it to cool yourself down, very portable. 

[The emperor has no clothes]

Is your shop/garage already insulated ? I would think it’s too big of an area if not.

[baldo]

We built a shop for our upholstery work 18 yrs ago, 30x40,  2x6 construction with good insulation. It's attached to the house, just picture a big garage. We framed two spots for 'window' A/C units, one on each floor, that we bought for the build. I believe they're 24000 BTU, 240V. It is more than enough to cool that size an area.

[Hook#3287]

At this time, in Massachusetts (every state is different) a Mechanical Permit is required to install a heat pump (mini split) appliance.  In that process, a ACCA form is required that specs out the building, equipment, even the position of the building related to north.  Over kill? Probably, but it's less than what's to come.

A Supply House will usually provide the info w/o cost, but may require a licensed professional involvement.

If you feel you can get by with a "wall shaker" (window a/c) and a fan or 2, that would be the easiest solution.  Some are excellent and have great longevity.  Like Baldo suggested, getting one installed semi permanent in the wall is good option but isn't great in the winter.

I'd suggest, if you decide on the window type, you do it soon before the present federal administration outlaws them.

I believe that's coming also.

[Rams]

how much time u spend in your HUGE garage?  Me being cheap and would work, is buy one of these I got for my daughter's house at Costco on sale for 300 bucks and be done with it.  Her house is 1000 sq. ft and cools it down fine except the far other end where bathroom and kitchen is, but surely helps in 90+ degree heat.  Am sure your man cave HUGE garage is insulated, so this would work fine and can be moved around.  Has a dual hose that needs to be vented out a window and also can be used for HEAT in the winter.  

https://www.costco.com/hisense-smart-sacc-8%2c000-btu-dual-hose-portable-air-conditioner-with-heat-pump.product.4000106320.html

300 is surely cheaper than pretty much anything else besides a window unit AC and this can be moved around in your garage so closer to where you need it to cool yourself down, very portable.  

I piddle around in my garage whenever I feel like it so, there's not a regular schedule but, I spend a lot of time out there.   I turn on the big screen and use it as background noise, sometimes just sitting in my chair looking at my fat ladies.   Turn wrenchs when I need to, mostly easy stuff, I'm not a tech.  
Already have one of those that I use in another out building.   It needs to stay where it is.

At this time, in Massachusetts (every state is different) a Mechanical Permit is required to install a heat pump (mini split) appliance.  In that process, a ACCA form is required that specs out the building, equipment, even the position of the building related to north.  Over kill? Probably, but it's less than what's to come.

A Supply House will usually provide the info w/o cost, but may require a licensed professional involvement.

If you feel you can get by with a "wall shaker" (window a/c) and a fan or 2, that would be the easiest solution.  Some are excellent and have great longevity.  Like Baldo suggested, getting one installed semi permanent in the wall is good option but isn't great in the winter.

I'd suggest, if you decide on the window type, you do it soon before the present federal administration outlaws them.

I believe that's coming also.

Code isn't a problem here in rural Mississippi, I didn't even need a permit to expand/add on to our home.   Seemed silly to me but, I checked and that is the way it is.   I agree with your assessment on what is easiest and cheapest to do.   That's most likely the route I'm going to take.   The truth is, with my knees, once I get down on the floor, I'm not getting up except to go back in to the house to cool off or grab another tool.  That may change when I get new knees. 

Is your shop/garage already insulated ? I would think it’s too big of an area if not.

Yes, garage bay doors, ceiling and walls are insulated.  

Rams  

[Jersey mike]

There are excellent free standing units which roll and come with a 10 foot or so retractable/collapsible 3”-4” exhaust hose and can be vented out a window or even to a dryer like vent in the wall. They’re a little pricey but very effective.

[Rams]

There are excellent free standing units which roll and come with a 10 foot or so retractable/collapsible 3”-4” exhaust hose and can be vented out a window or even to a dryer like vent in the wall. They’re a little pricey but very effective.

Mike,

Thanks for the information.   Saw those units and as you said, they are quite a bit higher in price.   Already started looking at window units.   After doing some investigation getting a unit that will cool 1148 square feet won't be that hard.   Just need to decide which one and come up with the money.   My allowance doesn't come until about mid-month. 

Rams

[f6john]

Hey, I thought you said half of nothing is nothing! You get a raise?!

[Rams]

Hey, I thought you said half of nothing is nothing! You get a raise?!

You are correct but, to get your half, you'll have to do the same silly stuff I get to do. 
BTW, you should expect a call just as soon as I get the loan application filled out.

Rams  

[Jersey mike]

There are excellent free standing units which roll and come with a 10 foot or so retractable/collapsible 3”-4” exhaust hose and can be vented out a window or even to a dryer like vent in the wall. They’re a little pricey but very effective.

Mike,

Thanks for the information.   Saw those units and as you said, they are quite a bit higher in price.   Already started looking at window units.   After doing some investigation getting a unit that will cool 1148 square feet won't be that hard.   Just need to decide which one and come up with the money.   My allowance doesn't come until about mid-month.  

Rams

FYI if you haven’t considered it already, be sure to measure your window(s) at fully opened to get the correct size of what fits that opening unless your plan is to definitely open up the wall for a permanent installation. If you plan on leaving it in year round there are exterior covers made to prevent some cold getting in. Some rigid styrofoam insulation helps too.

Many years ago, there were wall units that also had heat features as well, not sure about if that’s still a thing or if it may interest you.

There was also a company, I think Haier (spelling?) that made a unit that was wall mounted with a small condenser outside or something like that. They were made for established places that didn’t want to do a big renovation but wanted the feeling of central ac.

[scooperhsd]

Haier is known for minisplits - which is kind of what you're describing.

[Rams]

There are excellent free standing units which roll and come with a 10 foot or so retractable/collapsible 3”-4” exhaust hose and can be vented out a window or even to a dryer like vent in the wall. They’re a little pricey but very effective.

Mike,

Thanks for the information.   Saw those units and as you said, they are quite a bit higher in price.   Already started looking at window units.   After doing some investigation getting a unit that will cool 1148 square feet won't be that hard.   Just need to decide which one and come up with the money.   My allowance doesn't come until about mid-month.  

Rams

FYI if you haven’t considered it already, be sure to measure your window(s) at fully opened to get the correct size of what fits that opening unless your plan is to definitely open up the wall for a permanent installation. If you plan on leaving it in year round there are exterior covers made to prevent some cold getting in. Some rigid styrofoam insulation helps too.

Many years ago, there were wall units that also had heat features as well, not sure about if that’s still a thing or if it may interest you.

There was also a company, I think Haier (spelling?) that made a unit that was wall mounted with a small condenser outside or something like that. They were made for established places that didn’t want to do a big renovation but wanted the feeling of central ac.

Appreciate the advice, already accomplished the measuring of the window and had a good friend offer me a window unit that will fit free.   Says he doesn't use it now.   Says it works just fine and has greater capacity (BTUs) than anything I was considering.   The problem is, it's 220 volt and I don't have a 220 outlet anywhere near the windows.   We'll see what my electrician has to say about getting that wired up.   I'm thinking it'll be less expensive getting a large capacity 110 unit than to have that wall wired for 220.   We'll see.

Rams

[hubcapsc]

There's  a thing with too much air conditioner and humidity...

Something about the a/c kicks on and cools down so fast
that it kicks right back off... a lot of cycles and not enough
steady running to keep the humidity down...

-Mike

[Jersey mike]

There are excellent free standing units which roll and come with a 10 foot or so retractable/collapsible 3”-4” exhaust hose and can be vented out a window or even to a dryer like vent in the wall. They’re a little pricey but very effective.

Mike,

Thanks for the information.   Saw those units and as you said, they are quite a bit higher in price.   Already started looking at window units.   After doing some investigation getting a unit that will cool 1148 square feet won't be that hard.   Just need to decide which one and come up with the money.   My allowance doesn't come until about mid-month.  

Rams

FYI if you haven’t considered it already, be sure to measure your window(s) at fully opened to get the correct size of what fits that opening unless your plan is to definitely open up the wall for a permanent installation. If you plan on leaving it in year round there are exterior covers made to prevent some cold getting in. Some rigid styrofoam insulation helps too.

Many years ago, there were wall units that also had heat features as well, not sure about if that’s still a thing or if it may interest you.

There was also a company, I think Haier (spelling?) that made a unit that was wall mounted with a small condenser outside or something like that. They were made for established places that didn’t want to do a big renovation but wanted the feeling of central ac.

Appreciate the advice, already accomplished the measuring of the window and had a good friend offer me a window unit that will fit free.   Says he doesn't use it now.   Says it works just fine and has greater capacity (BTUs) than anything I was considering.   The problem is, it's 220 volt and I don't have a 220 outlet anywhere near the windows.   We'll see what my electrician has to say about getting that wired up.   I'm thinking it'll be less expensive getting a large capacity 110 unit than to have that wall wired for 220.   We'll see.

Rams

Depending on your windows, it may be possible to remove the lower sash completely, leave the upper window in and customize the lower opening to accommodate a window unit more “permanently”, with better insulation and aesthetically.

[Rams]

There are excellent free standing units which roll and come with a 10 foot or so retractable/collapsible 3”-4” exhaust hose and can be vented out a window or even to a dryer like vent in the wall. They’re a little pricey but very effective.

Mike,

Thanks for the information.   Saw those units and as you said, they are quite a bit higher in price.   Already started looking at window units.   After doing some investigation getting a unit that will cool 1148 square feet won't be that hard.   Just need to decide which one and come up with the money.   My allowance doesn't come until about mid-month.  

Rams

FYI if you haven’t considered it already, be sure to measure your window(s) at fully opened to get the correct size of what fits that opening unless your plan is to definitely open up the wall for a permanent installation. If you plan on leaving it in year round there are exterior covers made to prevent some cold getting in. Some rigid styrofoam insulation helps too.

Many years ago, there were wall units that also had heat features as well, not sure about if that’s still a thing or if it may interest you.

There was also a company, I think Haier (spelling?) that made a unit that was wall mounted with a small condenser outside or something like that. They were made for established places that didn’t want to do a big renovation but wanted the feeling of central ac.

Appreciate the advice, already accomplished the measuring of the window and had a good friend offer me a window unit that will fit free.   Says he doesn't use it now.   Says it works just fine and has greater capacity (BTUs) than anything I was considering.   The problem is, it's 220 volt and I don't have a 220 outlet anywhere near the windows.   We'll see what my electrician has to say about getting that wired up.   I'm thinking it'll be less expensive getting a large capacity 110 unit than to have that wall wired for 220.   We'll see.

Rams

Depending on your windows, it may be possible to remove the lower sash completely, leave the upper window in and customize the lower opening to accommodate a window unit more “permanently”, with better insulation and aesthetically.

While that may be true, I am not really interested in making this a permanent installation.  There my come a time when my buddy would ask for his A/C unit back.   One never knows and I don't want to take any steps that might be hard to back up on.

Rams

[Jess from VA]

I put a small (the smallest) window ac unit in my upstairs bedroom (because I couldn't sleep up there in summer without blasting my whole house central AC all night - $).  When I go to bed, I turn the house central up to 80, and my bedroom unit goes on at 70 something on low fan, and it's perfect, and saves money on electric (door closed).  In the morning, the bedroom unit goes off , and the house gets turned down to 70 something.     

I took it out every winter (to save wear and tear) but stopped that 15 years ago.  All I do is clean the filter once in a while.  It never precips a drop of water outside.  It's a Sharp brand unit and one the most reliable appliances I've ever owned.

Since it's 110, when I've had to go on generator from power outage, it's been a lifesaver (generator won't run any 220).  Of course it won't cool the whole house, but a least I have one room to survive blistering heat (and can sleep). 

The slide out wings on each side of the unit wouldn't even begin to insulate or keep bugs out.  So what I did was put insulation covered by rubber matting then duct taped it in place to both the inside and the outside of the window over the ac unit wings.  And I shoved long strips of foam insulation up in the top (open) double hung window to stop bugs there too.  The outside duct tape needed done over after 5-6 years.   

[Rams]

Jess,
It would seem that's the direction I'm headed. 

Thanks for the input.

Rams

[Kep]

While I did get my HVAC "cert" 15 years ago, I only got it so I could buy freon for my 1996 Ford Explorer.

Having said that, one of the issues with any HVAC unit is un restricted air flow to the outside unit (condenser I believe is the correct term).   That is where the freon is cooled so that it can be used, again, to cool the air in the evaporator (where the air to be cooled is circulated).  

So, while you could stack the "condensers" if the bottom one blows air up to the upper one, you have hot air trying to cool the freon (well maybe its not really freon any longer).   It will not cool as well.  

That is the biggest issue I would see with stacking.  

" That is where the freon is cooled so that it can be used, again, to cool the air in the evaporator (where the air to be cooled is circulated).  "


Regarding the mini-split, we purchased one for our enclosed porch.  It does its job but also has a separate "condenser" unit.  The only issue I have with the mini split is that, in my case, the evaporate where the air is heated or cooled is mounted above the door way to the porch.  Good for cooling since cool air is more dense and falls to the floor level. Seemingly bad for hot air since hot air is not as dense as cold air and will simply rise up from the mini-split.  The mini-splits are flow out does have a "thing" that is used to direct the air out either upwards or downwards.  

Again, I think the issue with stacking would affect the unit's efficiency.  

Just for informational purposes , the physics behind air conditioning is "HEAT TRANSFER"  and "de-humidification" (water from air removal) Despite popular belief , air conditioning is not throwing cold air into a room , it's actually a process of absorbing heat into the refrigerant that is passing through the evaporater coil (indoor coil) and transferring it out to the condensing unit (outdoor unit) and expelling the heat to the outdoor air through the condenser fan. The moisture from inside the house is collected on the condesner coil and runs into it's own drain pan , out the drain line and is disposed of. (or saved to be used in batteries as it is purified water). That is why it is essential to properly size an A/C system. Some believe you just put the biggest system in that you can but what happens is  that the heat is transferred so quickly and the thermostat satisfies before the humidity is removed from the conditioned space. That's it in a nutshell !

[carolinarider09]

Yes, all heating and cooling is basically "Heat Transfer".  Convection, Conduction, Radiate heat transfer all are methods that are and have been used. 

Same for a "radiator". Hot water in radiator enters the cooler room (thru the device there) and by natural convection or conduction heats the surrounding air.  As the air is heated it moves up.  As it rises, the cooler air below replaces it.  The hot water is cooled by the process and is then reheated in some way after it leaves the area. 

[Rams]

Just to clarify the "Stacking" of compressors.   I understand that blowing hot air up at the compressor upstairs would have reduced it's capability.   I should have stated this earlier but, I had already planned to divert that hot air to the sides of the upper unit with a sheet metal diverter placed eithier on the top of the lower compressor or the bottom of the upper compressor structural support.   Had already discussed this with a sheet metal shop.

But, that discussion is moot now, have already decided to go "cheap" and use a window unit or two.   Much cheaper and a whole lot less work to get it done.

Rams

[Cracker Jack]

While I did get my HVAC "cert" 15 years ago, I only got it so I could buy freon for my 1996 Ford Explorer.

Having said that, one of the issues with any HVAC unit is un restricted air flow to the outside unit (condenser I believe is the correct term).   That is where the freon is cooled so that it can be used, again, to cool the air in the evaporator (where the air to be cooled is circulated).  

So, while you could stack the "condensers" if the bottom one blows air up to the upper one, you have hot air trying to cool the freon (well maybe its not really freon any longer).   It will not cool as well.  

That is the biggest issue I would see with stacking.  

" That is where the freon is cooled so that it can be used, again, to cool the air in the evaporator (where the air to be cooled is circulated).  "


Regarding the mini-split, we purchased one for our enclosed porch.  It does its job but also has a separate "condenser" unit.  The only issue I have with the mini split is that, in my case, the evaporate where the air is heated or cooled is mounted above the door way to the porch.  Good for cooling since cool air is more dense and falls to the floor level. Seemingly bad for hot air since hot air is not as dense as cold air and will simply rise up from the mini-split.  The mini-splits are flow out does have a "thing" that is used to direct the air out either upwards or downwards.  

Again, I think the issue with stacking would affect the unit's efficiency.  

Just for informational purposes , the physics behind air conditioning is "HEAT TRANSFER"  and "de-humidification" (water from air removal) Despite popular belief , air conditioning is not throwing cold air into a room , it's actually a process of absorbing heat into the refrigerant that is passing through the evaporater coil (indoor coil) and transferring it out to the condensing unit (outdoor unit) and expelling the heat to the outdoor air through the condenser fan. The moisture from inside the house is collected on the condesner coil and runs into it's own drain pan , out the drain line and is disposed of. (or saved to be used in batteries as it is purified water). That is why it is essential to properly size an A/C system. Some believe you just put the biggest system in that you can but what happens is  that the heat is transferred so quickly and the thermostat satisfies before the humidity is removed from the conditioned space. That's it in a nutshell !

I believe the moisture in the inside air is condensed on the cold EVAPORATOR coil.
Not that anybody cares.

[Jersey mike]

A little OT;

Yesterday my wife heard from from her sister who lives in Vegas. Her central air went down yesterday morning or overnight sometime. The service guy got there late in the day/early evening, apparently it was a capacitor. It made me think maybe it’s a good idea to have a window unit or two for emergency situations like this or maybe a backup capacitor just in case.