Need rough sizing for metal building

[dansohvac]

Looking for a little advice for HVAC sizing as online tools are mostly for houses, not metal buildings. Talked to a couple of local pros and they do not seem to be asking enough questions to properly size things.

Location: 29307 Chappells, SC near Greenwood
20' x 30' metal building on concrete slab. 12' high plus ~3' peak on the 20' side
Walls and ceiling were sprayed with 2" closed-cell spray foam so call it R12 with minimal infiltration.
20' side faces almost due north (353 degrees) and has a roll up 10'x8' bay door (not insulated) and 18"W x 36"H window above it.
30' side facing east has uninsulated 36"W x 80"H walk in door.
Other two sides are unbroken.
Some trees on west side provide afternoon shade.
Roof is slate blue, sides are tan.

It's a workshop, not living space so was thinking of a heating and cooling mini-split that would keep humidity down and eliminate the temperature extremes all year yet be able to cool to ~80 in the high summer and heat to ~65 on the coldest days. Cooling is much more of a concern as we have more hot days than cold.

[dan sw fl]

Looking for a little advice for HVAC sizing as online tools are mostly for houses, not metal buildings.

Talked to a couple of local pros and
they do not seem to be asking enough questions to properly size things.

Location: 29307 Chappells, SC near Greenwood
20' x 30' metal building on concrete slab.
12' high plus ~3' peak on the 20' side

Walls and ceiling were sprayed with 2" closed-cell spray foam so call it R12 with minimal infiltration.

20' side faces almost due north (353 degrees) and has a roll up 10'x8' bay door (not insulated) and 18"W x 36"H window above it.

30' side facing east has uninsulated 36"W x 80"H walk in door.
Other two sides are unbroken.
Some trees on west side provide afternoon shade.
Roof is slate blue, sides are tan.

It's a workshop, not living space so was thinking of a heating and cooling mini-split
that would keep humidity down and eliminate the temperature extremes all year

yet be able to cool to ~80 in the high summer and
heat to ~65'F on the Coldest days.

Cooling is much more of a concern
as we have more hot days than cold.

As requested, ONLY
... a little advice for HVAC Sizing

[dansohvac]

This is great, thank you! I had to go look up some of the terms but it looks like 18K-24K will work well. I can now talk to a local installer and tell him what size unit I need. And I'm not calling the guy who recommended a 3.5 ton unit.

[pecmsg]

This is great, thank you! I had to go look up some of the terms but it looks like 18K-24K will work well. I can now talk to a local installer and tell him what size unit I need. And I'm not calling the guy who recommended a 3.5 ton unit.

I would still ask for there recommendations and how they got them.

[dan sw fl]

This is great, thank you! I had to go look up some of the terms but it looks like 18K-24K will work well. I can now talk to a local installer and tell him what size unit I need. And I'm not calling the guy who recommended a 3.5 ton unit.

That will be quite-a-trick telling the contractor what size is required.

What is the S.H.R. ?

Did you Check the Manual J which I perform in a few minutes?
Did you complete the ACCA Manual S?

What is the heat pump Thermal Balance Point ?

What is the heat pump Economic Balance Point ?

What is the advantage of heat pump use ?

[beenthere]

What kind of lights will it have? How many lights?

What kind of work shop?

What kind of equipment will be running in it?

Will any of the equipment have an exhaust system? If so, you need to know how much air is exhausted, so you know how much is brought in that will add to heating and cooling load.

How many people will be working in it.

Will large amounts of material be brought into building at one time? If so, this will add to cooling and heating load.

[crmont]

Go with the 3.5 ton, hopefully the daikin sky air with the suspended ceiling unit. If that's the system, that guy was right.

The system will give you the capacity to recover quickly. It also has good access for cleaning the fan motor and both sides of the evaporator coil. It also has a turn down of 14%, giving just under 6000 btu capacity in low stage. It also has the fan motor designed to push across 30'.

[dan sw fl]

Go with the 3.5 ton, hopefully the daikin sky air with the suspended ceiling unit.
If that's the system, that guy was right.

The system will give you the capacity to recover quickly.

It also has good access for cleaning the fan motor and both sides of the evaporator coil.
It also has a turn down of 14%, giving just under 6000 btu capacity in low stage.
It also has the fan motor designed to push across 30'.

Ability to recover quickly is DEFINITELY NOT the objective.

Location: 29307 Chappells, SC near Greenwood

Operation should be set-up from ~ early April to mid October to maintain < 57% Relative Humidity.
________________________________ 6 + months _________
_________________________ See CDD65 at bottom of the Greenwood County AP data provided.

OPERATION
.. AWAY _ 82'F
.. WORK _ 78'F _ Adjust T-Stat ~ 3 hours prior to Workshop activity

__________ KEEP IT SIMPLE _____

[dan sw fl]

... ONE Possibile Heat Pump System ___
___ Low Stage
17,100 BTU/HR at 95'F ODT __ 80'F / 63'F Inside __ 0.93 kw

__ High Stage
22,600 BTU/HR at 95'F ODT __ 80'F / 63'F Inside __ 1.64 kw

https://www.amana-hac.com/pdfviewer.....pdf?view=true

[crmont]

Imo, In a shop or garage, recovery and occasional use should be factored.

[dan sw fl]

Imo,
In a shop or garage,
recovery and occasional use should be factored.

A personalized, well thought out plan input into a simple Programmable Thermostat
ought to be sufficient in the Majority of applications.

[beenthere]

A personalized, well thought out plan input into a simple Programmable Thermostat
ought to be sufficient in the Majority of applications.

That works on fixed time of use shops and garages. But not on ones that aren't used on a regular schedule.

[dansohvac]

Based on info here, I was thinking about a Daikin mini split like the 24,000 BTU LV series FTXS24LVJU / RXS24LVJU. If I have the WiFi option added, I can flip it on from inside the house.