Heating and Cooling 2000sq ft

[BadMannerz]

I have been reading for days and days on this. Ive got a new construction 40x50x13 pole barn in Richmond, VA that is attached to a smaller shop (900 sg ft) and has a closable 10x10 opening between the two. has been sealed to the best of my abilities and am currently installing R19 in the walls with a 6 mill vapor barrier and R40 blow in, in the attic. 3 double pained, gas filled windows, 3 10x10 insulated garage doors, one 3.0 door The heating and cooling options are endless. I currently have a Woodmaster woodstove in the small shop that will get the job done easy for that 900 sq ft space.

I'm thinking a propane furnace with a/c and route the exposed ducting however I need to..... How many people have had Craigslist or other used heating and cooling scores? Things to look for? Obviously trying to be budget minded. If I have to wait for funds to do it right then that's what Ill do but, some of these deals on this used stuff is awesome! (if it isn't junk)

I would love to see pics of everybody's options, investment made, how they are working out, and cost of operation.

It gets cold here at times (down to 0* last week, and hot and humid in the summer 100*). This space will be used a lot. Almost everyday after work and every weekend.

Sorry if I'm leaving out any details but I will fill in the blanks as needed. Looking forward to some good feedback and info!!!!!!!!!!!

 

[matt_i]

Can you get natural gas? That would seem to be the cheapest heat.

Seems like something around a 100k split system with 3 tons of cooling would be about right (as a non-calculated WAG).

I'm going to guess that you are more of a cooling climate than a heating climate and so ceiling-mounted ductwork would be best. Menards has a wide selection of metal duct products if you have a store near you, special-order/free ship-to-store. I think they will even design the ductwork for you via the supplier for the ductwork.

 

[BadMannerz]

Can you get natural gas? That would seem to be the cheapest heat.

Seems like something around a 100k split system with 3 tons of cooling would be about right (as a non-calculated WAG).

I'm going to guess that you are more of a cooling climate than a heating climate and so ceiling-mounted ductwork would be best. Menards has a wide selection of metal duct products if you have a store near you, special-order/free ship-to-store. I think they will even design the ductwork for you via the supplier for the ductwork.

Thanks Matt i. No natural gas out here. Honestly its probably both heating and cooling... About 4 months of heating and 4 months of cooling. But this is Virginia and you never know. Highs were in the low twenties last week and tomorrow will be 65* We don't have Menards around here but I do have a couple friends that do HVAC work that I could talk too.

I know, if I have HVAC buddies than why am I asking on GF..... I want to get every bodies input because just as I have found with insulating techniques...... Everybody has a different method and budget.

Just trying to evaluate all avenues

 

[Dr Stan]

When I built my 24 X 48 ft shop I installed a HVAC unit (nat gas) purchased off Craigs List. I forget the tonnage, but its been more than good for me. In KY I have about the same seasons as VA and like you the swings in the weather the past few weeks has been nothing but crazy.

As to duct work I have two 12" diameter short ducts with "elbows" coming out of the sides of the unit so I can aim the air. I also have 4 ceiling fans and two 12" industrial circular fans to move the air. Consequently I do not use the AC very much.

I should also note my shop has a 10ft overhead door at the east end of the north wall and double man doors on the south end of the west wall. Open both of the doors, turn on the fans and I have as much cooling as needed 90% of the time.

 

[BadMannerz]

When I built my 24 X 48 ft shop I installed a HVAC unit (nat gas) purchased off Craigs List. I forget the tonnage, but its been more than good for me. In KY I have about the same seasons as VA and like you the swings in the weather the past few weeks has been nothing but crazy.

As to duct work I have two 12" diameter short ducts with "elbows" coming out of the sides of the unit so I can aim the air. I also have 4 ceiling fans and two 12" industrial circular fans to move the air. Consequently I do not use the AC very much.

I should also note my shop has a 10ft overhead door at the east end of the north wall and double man doors on the south end of the west wall. Open both of the doors, turn on the fans and I have as much cooling as needed 90% of the time.

That's good info Dr Stan. Yeah, this weather lately has been insane. Part of the cooling plans is so I can pull some of the moisture out of the shop in the extremely humid summers. I do metal fab, welding, cnc plasma, milling........... in this work space. Materials and equipment rusting is something I would like to alleviate (or at least slow down) with being able to finally condition this space.

 

[BadMannerz]

Here is a pic of the inside so far before any of the insulating... The old existing attached shop with the pass through is on the opposite wall out of view. You can see the existing shop in the second pic and the stove pipe from the wood stove already in place.

 

[HunterDan]

Gonna sub to this. I to have a 40x48 I'm going to be heating/cooling soon. I also saw a 4 zone mini split system that I may look into. Not to hijack, but Anyone think that would work?

https://www.alpinehomeair.com/viewp...from=froogle&gclid=CLCYq67VytECFZS6wAod0LUCtg

I'm thinking 2 units on each 48' wall?

 

[BadMannerz]

I started to go around last night with the can foam and seal up what I can. What is theory on leaving some of the open spaces at the bottom of the metal open so that any sweat moisture has a place to exit? And, sealing the open spaces at the header? Or leave those open so any sweat moisture can run to the bottom?

 

[HunterDan]

I went in mine with no lights on, and I sealed up every spot I could see light through. Top, bottom, Etc.

 

[DC73]

. . . but Anyone think that would work?

https://www.alpinehomeair.com/viewp...from=froogle&gclid=CLCYq67VytECFZS6wAod0LUCtg

I was going to recommend the OP check out Alpine Home Air before buying potential junk on Craigslist. A ductless mini-split should work well for most climates if it is sized appropriately. Like all heat pumps, it doesn't put out the hot air like a gas or propane furnace would so if you are looking for that hot air in your face feeling, you won't get it with a heat pump.

If you can do things yourself and can size and source duct work appropriately, both of you might come out ahead cost wise by getting a traditional Goodman furnace and AC direct from Alpine Home Air.

One caution about newer gas furnaces - the high efficient furnaces are condensing furnaces and so they need a condensate drain. Also, the furnace condensate is highly acidic and some people recommend you don't drain them directly into a septic system. You can always build a neutralizing filter and install it in the drain. They are easy to make.

DC

 

[yeldogt]

I use a 37k propane unit 80% -- and it can over heat my 1800sf studio. It's well insulated.

I think you will find a single room well insulated space will not require as much cooling as you think.

 

[HunterDan]

Dc thanks for the tips!

I've never done any type of hvac work so id be a little leery in doing that...do you think that 4 zone mini split would work?

 

[600SL]

I was originally planning mini splits but fortunately I didn't have the money at the time and waited until I moved everything in. I found that I had no wall space left. The ceiling mounted cassette styles would have worked but I opted for a standard heat pump with air handler on the ceiling.

So I'm just recommending you consider your future needs for wall space. If you decide mini split consider the ceiling mounted cassettes if your wall space will be at a premium.

 

[DC73]

...do you think that 4 zone mini split would work?

The concept will certainly work. The size of the equipment needs to be right. That unit you linked only provides 30,500 BTUs of heating and 2.5 tons cooling. My shop here is around 1,000 sq. ft. and heat loss calculations showed a minimum furnace size of 28,500 BTUs and an AC need of 1.5 tons.

2.5 tons of AC would probably work fine for your size shop in my area but I know your location is much more humid and that's a factor as well.

The heat output seems too low for your needs BUT, if your shop is very well insulated and/or you don't need to heat it to shirt sleeve temperatures like I prefer my shop, it might work fine.

You might want to look at the next size up which was 3.5 tons of AC and 44,500 BTUs of heat.

You really need to get a good feel for what the heat gain and heat loss values are for your building and then you can size the equipment correctly. There are websites that provide heat load software you can use on a trial basis to estimate if you don't have any other way.

The danger in over sizing AC equipment is that it will short cycle and therefore not run long enough to lower the humidity in the space. But, under sizing will cost you money as the unit may run continuously and never get the place warm enough or cool enough.

My gut tells me your needs are probably right between the two units and if that truly is the case, you could probably get by with the smaller unit by making sure you have plenty of insulation and seal all points of air infiltration.

The folks at Alpine Home Air might be able to help you size correctly. They were very helpful when I had questions.

DC

 

[theoldwizard1]

Honestly its probably both heating and cooling... About 4 months of heating and 4 months of cooling. But this is Virginia and you never know.

Not cheap to install, especially on a building that big, but the lowest OPERATIONAL cost will be a couple of mini-split heat pumps.

You will need at least 2 compressors, one on each long side, and at least 4 or 5 air handlers on each side.

 

[theoldwizard1]

I started to go around last night with the can foam and seal up what I can. What is theory on leaving some of the open spaces at the bottom of the metal open so that any sweat moisture has a place to exit? And, sealing the open spaces at the header? Or leave those open so any sweat moisture can run to the bottom?

It is going to take a lot of time and a lot on cans. Hire someone and have them do 1-2" of spray foam. Have them quote 4"+. You might be surprised.

 

[yeldogt]

Properly insulating the space will pay you back in electric and propane .. a skim of foam would be the best way to do it.

You can heat large space with only one source -- I have heated many buildings this way. But I keep them heated. Trying to bring a space up to temp 15 degrees requires a different strategy. My 1700sf studio is heated by my through the wall propane heater -- but I don't have any huge heat loss areas ... How tight are the doors. Even with heat -- small leaks really take a toll on comfort,

Buying used equipment that is not efficient is foolish if you are going to be running it often and you don't have cheap electric propane. For those with cheap electric -- getting better equipment and maintaining temp is the best solution.

 

[HunterDan]

It is going to take a lot of time and a lot on cans. Hire someone and have them do 1-2" of spray foam. Have them quote 4"+. You might be surprised.

I know I was, 22k and 24k for closed cell for the whole building!

I would love to do spray foam, but at that cost, I just can't see going that route

 

[hemifalcon]

Yeah--keep shopping around.. I really am disgusted by the costs being charged for spread foam..


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[BadMannerz]

I was quoted $4000 just for the walls and that was only 1.5'' thick. What I have started to do is to line the inside of the building with Tyvek and seal off all edges. Then I will R16 batt the walls, then 6 mil vapor barrier, then metal panels. I know spray foam has its advantages but, this method will cost me less than $1000 an Ill have R16 in the walls instead of R10 with 1.5" of foam. I know I can batt over the foam but that's more and more cost adding up. I'm taking way more time than any contractor would to ensure minimal air movement into the conditioned space. Ill post up some pics tonight.

 

[DC73]

. . . line the inside of the building with Tyvek and seal off all edges. Then I will R16 batt the walls, then 6 mil vapor barrier, then metal panels.

Before you get too far along, read this recent article about vapor retarders (barriers): http://www.finehomebuilding.com/membership/pdf/174534/021264084-87-EnergySmart.pdf

Here’s the short version:
• Most buildings don’t need polyethylene anywhere, except
directly under a concrete slab or on a crawlspace floor.
• The main reason to install an interior vapor retarder is to keep
a building inspector happy.
• If a building inspector wants you to install polyethylene in a
wall or ceiling, try to convince him to accept a layer of vapor-
retarder paint or a smart retarder instead.
• Although most walls and ceilings don’t need a vapor barrier,
it’s always good to include an interior air barrier. Air leakage is
far more likely to lead to problems than vapor diffusion.

Your metal panels will also be a vapor barrier if the seams are sealed. Your walls need to be able to dry to one side. The worst thing to do is create a moisture sandwich where you trap moisture inside your walls.

DC

 

[BadMannerz]

Before you get too far along, read this recent article about vapor retarders (barriers): http://www.finehomebuilding.com/membership/pdf/174534/021264084-87-EnergySmart.pdf

Here’s the short version:
• Most buildings don’t need polyethylene anywhere, except
directly under a concrete slab or on a crawlspace floor.
• The main reason to install an interior vapor retarder is to keep
a building inspector happy.
• If a building inspector wants you to install polyethylene in a
wall or ceiling, try to convince him to accept a layer of vapor-
retarder paint or a smart retarder instead.
• Although most walls and ceilings don’t need a vapor barrier,
it’s always good to include an interior air barrier. Air leakage is
far more likely to lead to problems than vapor diffusion.

Your metal panels will also be a vapor barrier if the seams are sealed. Your walls need to be able to dry to one side. The worst thing to do is create a moisture sandwich where you trap moisture inside your walls.

DC

Isn't the Tyvel designed to let the wall "dry" to the outside? There is 1.5" of empty air space between the tyvek and the outside metal. The Tyvek is designed to breath from the inside out. So does my application still apply to this theory if the Tyvek is not actually touching the outside metal?

I would think it would be easier to put up a poly barrier than it would be trying to seal each metal panel to each other on the overlap and then seal the top and the bottom of each panel. Maybe I am overkilling this....... But I am planning for heating and cooling costs in the future and now is the time to get it right.

Thanks for the info!

 

[BadMannerz]

Here is a pic of what I'm doing.

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[STINEY]

Subscribed.

Thats a nice building, and a nice job with the Tyvek.

 

[BadMannerz]

Subscribed.

Thats a nice building, and a nice job with the Tyvek.

Thanks Stiney. This thread started out about heating and cooling options but its turned into my sealing and insulating project. I will keep it going with pics as I move forward. All the material are in the building but, not much happens on it during the week right now. Its kind of unique seeing how I didn't rap the building before the metal went on the outside. Learned a lot on this build and still learning every day!!!

 

[DC73]

Isn't the Tyvel designed to let the wall "dry" to the outside? There is 1.5" of empty air space between the tyvek and the outside metal. The Tyvek is designed to breath from the inside out. So does my application still apply to this theory if the Tyvek is not actually touching the outside metal?

I would think it would be easier to put up a poly barrier than it would be trying to seal each metal panel to each other on the overlap and then seal the top and the bottom of each panel. Maybe I am overkilling this....... But I am planning for heating and cooling costs in the future and now is the time to get it right.

Thanks for the info!

I think your application of Tyvek is fine. It's the interior poly that could be an issue. Based on the article I linked, you don't need poly. A definitive source of info on the subject would be to post on the GreenBuildingAdvisor Q&A forum where some building science gurus hang out.

DC

 

[checkthisout]

*I* would think that sealing the wall cavity would lead to rot. I don't understand how the Tyvek would do anything because right behind it is impermeable steel.

I would think the best type of insulation when you have a non-permeable outer wall would be the old Mike Holmes go to.....Sprayfoam.

Just in the walls, not the ceiling.

 

[BadMannerz]

*I* would think that sealing the wall cavity would lead to rot. I don't understand how the Tyvek would do anything because right behind it is impermeable steel.

I would think the best type of insulation when you have a non-permeable outer wall would be the old Mike Holmes go to.....Sprayfoam.

Just in the walls, not the ceiling.

What the Tyvek does is eliminate (or try ) air movement into the insulated section of the wall. Moving air inside an insulated wall is bad. Ever seen a home wrapped in Tyvek? What I'm doing is no different than the method used to build a home, just in a different order. One sheet of outer metal by itself is non-permeable. Fifty sheets overlapping each other with air gaps at the top and bottom of each creates a very permeable layer.

 

[STINEY]

The moisture-being-locked-in-the-wall thing is dependent on location.

If you are in a part of the country where you need to heat in the winter, you want the moisture barrier on the INSIDE of the insulation.

If you are in a part of the country where you do not need to heat in the winter, but do need to cool in the summer, you want the moisture barrier on the OUTSIDE of the insulation.

Moisture in the form of humidity in the air will condense on any item if the dew point is reached. Dew point is measured in terms of the difference of temperature. That moisture does not care where that surface is, only which side is colder.

Think back to that last cold beer you had. Whether in a can or a glass, moisture formed on the surface of the object that was colder than the air around it.

But only in an environment where humidity is present, and also only when the difference in temperatures of the object and the air are great enough (reach the dew point).

Now imagine instead of your cold beer, your cold building faces a surprise day that is suddenly warmer than usual. Or your warm building faces a surprise day that is suddenly colder than usual.

Presto, damp moisture barrier. Whether the insulation side is damp or the non-insulation side is damp is up to how you installed it.

Its not an exact science by any means. Some experts actually recommend no moisture barrier for climates that need both cooling and heating. That minimizes moisture being trapped in walls, or at least gives them a chance to dry out.


I know this isn't really very helpful. Trust me, I have studied long and hard on the topic of where to place the moisture barrier, and there is simply no cut-n-dried answer. Wish there was, then I would know which way to go about insulating my own shop.

That seems to be a plus to the spray-foam closed cell insulation. Each micro-bubble has its own moisture barrier, so the insulation cannot become damp internally. Something to ponder anyways.

 

[BadMannerz]

The moisture-being-locked-in-the-wall thing is dependent on location.

If you are in a part of the country where you need to heat in the winter, you want the moisture barrier on the INSIDE of the insulation.

If you are in a part of the country where you do not need to heat in the winter, but do need to cool in the summer, you want the moisture barrier on the OUTSIDE of the insulation.

Moisture in the form of humidity in the air will condense on any item if the dew point is reached. Dew point is measured in terms of the difference of temperature. That moisture does not care where that surface is, only which side is colder.

Think back to that last cold beer you had. Whether in a can or a glass, moisture formed on the surface of the object that was colder than the air around it.

But only in an environment where humidity is present, and also only when the difference in temperatures of the object and the air are great enough (reach the dew point).

Now imagine instead of your cold beer, your cold building faces a surprise day that is suddenly warmer than usual. Or your warm building faces a surprise day that is suddenly colder than usual.

Presto, damp moisture barrier. Whether the insulation side is damp or the non-insulation side is damp is up to how you installed it.

Its not an exact science by any means. Some experts actually recommend no moisture barrier for climates that need both cooling and heating. That minimizes moisture being trapped in walls, or at least gives them a chance to dry out.


I know this isn't really very helpful. Trust me, I have studied long and hard on the topic of where to place the moisture barrier, and there is simply no cut-n-dried answer. Wish there was, then I would know which way to go about insulating my own shop.

That seems to be a plus to the spray-foam closed cell insulation. Each micro-bubble has its own moisture barrier, so the insulation cannot become damp internally. Something to ponder anyways.

I gotcha Stiney. I'm located in Chesterfield, VA. Its just south of Richmond. We get cold winters 0* at night sometimes mostly teens and twnenties for lows on average and 100* summers with high humidity. My intent with the Tyvek was to keep moving outside air from infiltrating the insulated wall. So no barrier on the conditioned side of the insulation? All my batts are UNFACED. I thought I had a plan together!

 

[BadMannerz]

I have found information all over the place that says to put the poly on the conditioned side of the insulation, and info that says not to use it. Can anybody that has been through this decision close to my climate please chime in and tell me if they have had any negative effects? I'm getting close to needing to make a call on poly or no poly.....

 

[600SL]

I have found information all over the place that says to put the poly on the conditioned side of the insulation, and info that says not to use it. Can anybody that has been through this decision close to my climate please chime in and tell me if they have had any negative effects? I'm getting close to needing to make a call on poly or no poly.....

Well I'm North Carolina. The vapor barrier went to the inside. But I have steel construction with optional steel interior walls. Without the interior walls it would be impractical to put the barrier to the outside. You can see my construction in the link below.

 

[BadMannerz]

Well I'm North Carolina. The vapor barrier went to the inside. But I have steel construction with optional steel interior walls. Without the interior walls it would be impractical to put the barrier to the outside. You can see my construction in the link below.

600SL, Just got done checking out your build. That's an awesome shop! Great work. I wish I had started this on another thread... I think I will opt to go with no vapor barrier on the conditioned side of the insulation. I have bee thinking hard about what some of the other members has suggested, gone to the links provided and done additional research as well.

I finally have my head wrapped around the theories at work and what's need based on the construction methods used.

 

[Mike.VA]

I am in the process of having a 32 x 44 built and considering using a mini split, either a 3 or 4 zone unit. I found some on Amazon for about $2,500.00 and most reviews are pretty good.
Since I have three areas in the garage, I was thinking of one zone in each area and in the largest area, maybe two.
Concerns are mostly - utility cost of running the unit.

 

[600SL]

I am in the process of having a 32 x 44 built and considering using a mini split, either a 3 or 4 zone unit. I found some on Amazon for about $2,500.00 and most reviews are pretty good.
Since I have three areas in the garage, I was thinking of one zone in each area and in the largest area, maybe two.
Concerns are mostly - utility cost of running the unit.

Be careful if you are considering mini splits. They are available in wall mount and ceiling cassettes. My wall space filled up really quickly so cassettes would have been the only option. In the end I went with a standard heat pump. Funny I found my 3.5 ton heat pump system at $2500. Thought I would get away with $3500 after the line set and ducting, wrong. About $5500 all said and done. The little stuff adds up real quick. I'm sure the mini splits have a lot less of that but be warned.

 

[DC73]

I have found information all over the place that says to put the poly on the conditioned side of the insulation, and info that says not to use it. Can anybody that has been through this decision close to my climate please chime in and tell me if they have had any negative effects? I'm getting close to needing to make a call on poly or no poly.....

Poly is old school and is no longer recommended. Did you read the article I linked in Post #21? Or visit the GreenBuildingAdvisor Q&A forum I linked in Post #26. Those two are better sources of info than anything you'll get here.

DC

 

[BadMannerz]

Poly is old school and is no longer recommended. Did you read the article I linked in Post #21? Or visit the GreenBuildingAdvisor Q&A forum I linked in Post #26. Those two are better sources of info than anything you'll get here.

DC

I did DC73. Thanks for the link and the site advice. After reading the info there and some other research Ive opted to go WITHOUT the vapor barrier on the inside.
I actually just came inside to get some coffee and figured I would check GJ this morning. Its like an icebox in the new shop right now! I'm jumping around the project and actually throwing up batts as we speak.
Ive got to try and keep some heat in there. The woodstove in the other shop wont help in the new shop yet and the torpedo heater is so annoying!
Last night I had a friend come over the look at his Jeep turbo project, we could see our breath as we were discussing the custom turbo manifold specifics..... Dont like being cold