65 in the shop when it's 33 outside?

[Hobby_Man22]

I went to the shop today turned on the heat pump and it went from 48 to 69 in about 5hrs I think. Then the temp dropped to 33 and it when down to 66 degrees and stayed there. I have a good man 5 ton unit 60,000 btu. I just about have all the insulation up on the roof. Most is up on the walls, how critical is insulation on the walls? I'm about to call the installer and tell him the unit doesn't keep up. In mean it heats, but it showing run the entire 9hrs I'm at the shop. It was in auxiliary heat mode too, so it was pulling 55 amps that whole time. It does have a 15k heat strip in it too. I wonder if it needs to be upgraded to 20. Then again ibwobder if I'll have the same issue in the summer where it doesnt cool. It's sized right for a 30x50x12 building. 5 ton heat pump 61,000 btu.

 

[Dogmeat]

Holy shidt……...55 amps....what an EXPENSIVE setup!! My natural gas 45k ceiling mounted heater only uses 1/2 gallon per hour....and at my $1.45/gallon cost, I'd say my setup if FAAARRR cheaper than your...ah....behemoth energy gulping monster!!
Sure am glad I was smarter than SOME people in making such decisions!!

 

[MushCreek]

Aren't you guys in TX having record cold? How often does it really get that cold? BTW- my shop was 44 yesterday, all day. No heat, no insulation. I do have a 5000 watt heater, but it's no more effective than a mouse breathing on you. It's just an expensive hand warmer.

 

[jmarkwolf]

Same here.

My 45K ceiling mounted natural gas heater keeps my detached 28ft x 30ft shop in Michigan at 55degF when I'm not out there and will increase to 70degF in a half hour when I am out there. R19 insulation everywhere.

Forgot to mention, that the walls are covered with T1-11 and the ceiling is covered in drywall. Have a ceiling fan, and the furnace is natural gas.

 

[kaymccampbell]

Until all your insulation is up, everywhere, and you have your final wall finishes installed, you really can't tell how your heat pump will perform in your shop.

 

[CombatNinja]

I thought all Texans were being called on to reduce power consumption amid the ongoing crisis there? Good show running a 55 amp heater in a partially insulated shop during a cold snap.

 

[Dragfluid]

As Kay said, only after your insulation is completed, will you know how good your heating system is. And you've got some unusual weather down there on top of it.

 

[yeldogt]

Have you even done a heat/ cooling load on the building ?

Often in TX the AC is the sizing requirement for the equipment and the strip is to make up the difference since the heat is less important. The strip is sized to the anticipated outside temp.

W/O knowing the loads -- no one can help you. W/O insulating -- the loads will not match the design.

Why would you think insulating would not be important ? W/O you are heating the outside

 

[karoc]

Your equipment is fine, its doing all it can under these conditions and till your finish insulating. But to get it up to 66 is pretty good but expensive. Its your shop to heat/cool they way you want.

 

[WisJim]

My 24 by 40 foot building with attic above has been staying in the 40s F with just a 1200 watt electric space heater for the last couple of weeks, when lows were down to 22 below and highs below zero. INSULATION IS KEY!!!!. I'm sure my shop will be even warmer when I get the interior doors installed so I'm not heating the unoccupied attic room and the garage.
By the way, my 18k BTU minisplits in the house are on 20 amp breakers and usually draw about 5 to 8 amps, and have been putting out lots of heat even when it is below zero.

 

[Rc_Guy]

Our infloor gas boiler heat is keeping up just fine, -34° last week and the house stayed at 72° and the garage was 65°

 

[930dreamer]

The heat pump air will be a sorta warm air as it uses the ambient air also. With the record cold this week it's probably running in EM heat mode. We didn't go back with a heat pump just a furnace because we want HOT air as heat.

 

[racecougar]

Until all your insulation is up, everywhere, and you have your final wall finishes installed, you really can't tell how your heat pump will perform in your shop.

Bingo.

 

[Innovate1]

Until all your insulation is up, everywhere, and you have your final wall finishes installed, you really can't tell how your heat pump will perform in your shop.

Exactly! The insulation is there for a purpose. You don't have all your ceiling or wall insulation done and you expect the unit to do just fine during a record cold spell. If it was able to do that it would be greatly oversized.

I would turn down the thermostat until the insulation is finished and then see how things run.

 

[roc_on_the_rocks]

Aren't you guys in TX having record cold? How often does it really get that cold? BTW- my shop was 44 yesterday, all day. No heat, no insulation. I do have a 5000 watt heater, but it's no more effective than a mouse breathing on you. It's just an expensive hand warmer.

How big is your shop??

 

[metlmunchr]

When you regularly run the thermostat up and down on a heat pump that has resistance heat backup, you end up doing almost all of your heating with the resistance heat. In the typical setup, anything more than a 3 to 4 degree differential between the space temperature and the setpoint will bring on the resistance heat. Doing the pogo stick routine on the stat substantially negates the advantages of having a heat pump.

With the outdoor temp in the mid 30's you should expect at least 40K btu from any current 5 ton heat pump. Add another 52K btu for 15kW of resistance heat, and you're at 90K+ btu. On 1500 sq ft that even remotely resembles "insulated and sealed", 90K should easily raise the space temp by 15° or more per hour, and it should also keep on raising the temp to any setpoint you choose.

Real world example.... The workshop section of my detached garage is 750 sq ft. R19 insulation overhead. Concrete block walls with stucco exterior and no insulation. Two 70's vintage 9x7 wood panel overhead doors that I've insulated with R7 rigid foam. Heat is a 5kW electric unit heater (17K btu). 5kW will bring that space from the mid 30's to the mid 60's in less than 2 hours with the outdoor temp remaining in the mid 30's. Once it's up to temperature, the heater will maintain it at a comfortable working temp by running no more than 20-25 minutes per hour.

I plan to install a 1.5 ton mini split this spring, primarily to have a/c, but also to reduce the heating cost by half or more since I spend a lot more time out there now that I'm retired. But, the point is, my garage is half the size of the OP's and poorly insulated yet once it's initially up to temperature I can maintain the temp with about 1/10 of the btu's the OP is using to try to heat his almost fully insulated garage with substantially identical outdoor temps.

Something in this picture doesn't add up. A few pics showing the duct layout and the amount of insulation actually completed within the building might be useful in spotting the problems.

 

[Daniel Dudley]

If you have a sizable concrete slab, and you didn't insulate the bottom of the slab, it is always going to transmit ground temperature, which is about 55 degrees. Once your building is insulated, it will be fairly easy to heat it to 55 or 60, but the hotter you try to make it, the more you will be trying to heat the ground. OTOH, in the summer it will be pretty easy to get the cooling down to where you want it, because the ground temp will be helping you out.

The better your insulation, the more true this is. 55 or 60 in the winter is plenty warm enough for me to work, but it isn't t shirt temperature. Lack of insulation in your walls and ceiling expose your building to a heat or cooling source of infinite capacity, which will easily effect the temperature of your slab.

People don't talk about this much, I don't know why.

 

[MushCreek]

How big is your shop??

28X32, with a 12' ceiling and no insulation. The big sliding doors don't help, either. I'm going to have to find a way to seal them up during weather extremes.

 

[tonyciambrone]

I just about have all the insulation up on the roof.

This whole thing means essentially nothing. How much insulation, what r-value, what type, what pitch roof, ceiling or no, interior or exterior insulation, etc etc. Same for walls. There is no way to understand how well or poorly insulated and sealed your building is from your post.

 

[tonyciambrone]

28X32, with a 12' ceiling and no insulation. The big sliding doors don't help, either. I'm going to have to find a way to seal them up during weather extremes.

Put a coat on...why try to run a heater in there at all?

 

[racecougar]

This whole thing means essentially nothing. How much insulation, what r-value, what type, what pitch roof, ceiling or no, interior or exterior insulation, etc etc. Same for walls. There is no way to understand how well or poorly insulated and sealed your building is from your post.

Judging by what is posted, I'm going to lean heavily toward "poorly".

Put a coat on...why try to run a heater in there at all?

Exactly. Without any insulation whatsoever all you really have is a windbreak. A little 5kW heater isn't going to heat a large uninsulated space.

 

[Cryptic1911]

just ******* in the wind trying to heat with no insulation

 

[Kev442]

Missing any ceiling insulation renders the rest less than 50% effective. Picture a dam with one sluice gate open. Heat just pours out the one area.

 

[MushCreek]

Put a coat on...why try to run a heater in there at all?

Hard to do anything meaningful with winter gloves on. My hands get cold, and I've learned that you cannot warm up a 2000 lb. milling machine with your hands. I turn the heater on, and go over to it periodically to warm my hands. It actually does slowly warm it up; maybe ten degrees over a couple hours.

 

[niget2002]

My 26x50 insulated shop has a 5 ton heat pump in it. Even then you can feel the draft flowing through the doors.

I typically run the heat up to 65f when I'm working out there.

One thing I'll say is that right now it's 60+ in the shop with the outside air at 34f. The sun beating on the metal building does a good job of adding heat.

Sent from my LM-G820 using Tapatalk

 

[NUTTSGT]

Is this the first time you turned on the heat ? If not what was it set on ? Between the lack of insulation, you're (I'm guessing) trying to heat up a big chunk of cold concrete.

 

[ace10]

Cannot imagine why there is an electrical supply issue in the area.

 

[Bert_]

Get the thing sealed up and insulated, then turn the heat on and leave it to a reasonable temperature.

It will never keep up until the building is done. It's not designed to.

 

[Hobby_Man22]

This whole thing means essentially nothing. How much insulation, what r-value, what type, what pitch roof, ceiling or no, interior or exterior insulation, etc etc. Same for walls. There is no way to understand how well or poorly insulated and sealed your building is from your post.

No ceiling. R30 insulation on both roof and walls. 5 ton 60k heat pump no exterior insulation it's a metal building. Minimal roof pitch I'm not sure what it is. 30x50 12ft tall building. Using mineral wool 24x47 7.75" thick batts.

 

[Hobby_Man22]

Get the thing sealed up and insulated, then turn the heat on and leave it to a reasonable temperature.

It will never keep up until the building is done. It's not designed to.

I put a bunch more in today. It was 74 inside and 38 outside. It's getting better. I need to figure out a way to seal up the roll up doors. It has 2 10x10 roll up doors. It would be cool if I could make some kind of curtain to just slide across and seal up the air coming through the tracks on each side. That's the biggest air leak in the whole building

 

[Hobby_Man22]

So does the cold metal just **** the heat out? Is that where most of the heat loss comes from? Or is it the warm air constantly making contact with the cold walls?

 

[imjustdave]

if your from Texas and this question is real then.... I feel the rest of the world understands why Texas is having an issue.

For the uneducated, insulation only works when you have it. every location and hole that isn't sealed and insulated single pane windows is r1 at best.

not suprisef half insulation on the building, metal doors.... with zero insulation. heat is on full blast can't keep up even with 50+amps worth...

advice turn off the heat, help the community and your bill, insulate, get a FLIR camera to find and fix issues.


Sent from my SM-N986U using Tapatalk

 

[Hobby_Man22]

The gas lines froze, that's why we had power issues. There's nothing wrong with the lines. I haven't even seen a single center point energy truck. It's not because I want heat in my shop. Sorry but every other house in Texas with only electric pulls 55 amps too. Houses here are designed for 110 degree temps not 17 degree temps.

 

[metlmunchr]

Does the building have actual roll up doors that roll up into a coil at the top of the opening? Or does it have overhead doors that roll up along a pair of tracks and lay horizontally near the ceiling when open? I ask because classic interlocking leaf steel roll up doors are giant energy wasters in both winter and summer. Overhead doors can be just as bad if not insulated, but the majority of overhead doors installed in commercial type buildings in the last 30 years are internally insulated.

In either case, the door tracks are normally adjustable for clearance between door and opening via slots in their mounting brackets, and door installers are notorious for leaving the gaps way too wide since that's quick and easy and they aren't paying the utility bills.

FWIW, any building insulated for 110° is, by default, also insulated for 10°. Of course all that assumes the electricity keep on flowing as anything will eventually freeze with no heat source.

 

[drivesitfar]

TEX: if you can buy a monitor for heat loss or just temp gauge type gun you'll find your issues and you can address them one at a time or all at once.

one of our members lives in a 100 year old home in Canada and his temps last week were -35C or -31F and probably a lot colder than yours and he rarely complains cause he's done the work to insulate and eliminate heat loss and he keeps the cold out.

here's a link to his thread and sorry i can't tell you which posts have his thermal images that show where heat is escaping, but his entire thread is full of good information.

https://www.garagejournal.com/forum/showthread.php?t=263351&highlight=woody

good luck!!

 

[Bert_]

So does the cold metal just **** the heat out? Is that where most of the heat loss comes from? Or is it the warm air constantly making contact with the cold walls?

Insulation slows down the transfer of heat. The heat in your building wants to disperse. Without insulation there isn't much to stop it.

Metal panels have very little ability to stop heat transfer.

Air sealing is also a big deal. Insulation doesn't help much if there are places that air can blow right past it.

 

[Jazz1]

Is this the first time you turned on the heat ? If not what was it set on ? Between the lack of insulation, you're (I'm guessing) trying to heat up a big chunk of cold concrete.

If the building was properly insulated it could take 3 days to heat that concrete. I’m in cold climate and throw a fire on every day even if not working in garage just to keep that heat sink from getting stone cold.

 

[glentre]

A 5 ton unit for your 1500 sq ft is actually an overkill if your building and doors are properly insulated and you have addressed air infiltration around the doors and windows. The winter temps in our area go down to the teens and my 3 ton heat pump at 380 sq ft per ton is more than adequate to keep the garage at 70* and is really too much capacity for the summer in the high 90's. Yours at 300 sq ft per ton is a bit more capacity than mine.

Operating your unit when the building insulation is not finished sounds like you are running with the resistance heat coils on all the time, thus your high power consumption.

Glen

 

[drivesitfar]

I put 3/4 inch rubber horse mats on our 2 car garage floor that helped a bit when i was using it as a gym, but when we upgraded from wood to metal and insulated garage doors i bet it warmed up the garage 10 or more degrees. now to finish insulating and heating so i can work out there in comfort next winter. our temps don't get much below teens, but even 40 is cold to me at 65 years old now.

 

[Strouty]

I put a bunch more in today. It was 74 inside and 38 outside. It's getting better. I need to figure out a way to seal up the roll up doors. It has 2 10x10 roll up doors. It would be cool if I could make some kind of curtain to just slide across and seal up the air coming through the tracks on each side. That's the biggest air leak in the whole building

Are you doing naked hot yoga in there?