65 in the shop when it's 33 outside?

[boatshoes]

This whole thread seems tone-deaf. Don't try to truly heat your shop until it's insulated, set it for 45 or something. Save some power capacity for the rest of your state. Do your part.

 

[Renegade1LI]

I have probably the same unit, I agree with completing insulation and wall coverings, but that unit is only good as a heat pump to about 34 degrees.I use mine at 35 and above any lower it kicks on the emergency heat, you would need to get a 22 seer or higher to be efficient below 34, I've had mine 3 years and works great at 35 and above, it is however a good back up heat source if the boiler goes out. I wired mine for HP first, oil boiler as emergency, then the 15kw heat strip.

 

[DOUGD]

Glad you have all the electric you need in your part of Texas................

 

[Renegade1LI]

This is off a page for Goodman heat pumps.
A heat pump split system is an energy-efficient way to heat and cool your home year-round. Basically, a central air and heat pump system is an air conditioner that also works in reverse to heat your home in the winter.

If you live in a region with mild winters (mostly staying above 35 degrees), a heat pump system is the perfect way to save on your energy costs all year long. For those in colder regions, consider an AC/furnace system, since a heat pump will not be efficient during cold months.

 

[ace10]

....For those in colder regions, consider an AC/furnace system, since a heat pump will not be efficient during cold months.

The Mitsu Hyper heat units pull heat at temps below zero F.

Mine have no issues with 6B/7A winter climate here.

 

[Renegade1LI]

The Mitsu Hyper heat units pull heat at temps below zero F.

Mine have no issues with 6B/7A winter climate here.

I agree about the mitsu, it's the Goodman that is not efficient below 35.

 

[slowtwitch73]

My 7500 electric heater kept my garage/shop at 50 even when it was below zero for a number of days.. even with a sub optimal garage door. Heater only cycled couple times an hr for 2 minutes each time. R33 in ceiling, 16 in walls, one double car door, one man door. Op's heating sounds wonky.

 

[dg57]

This whole thread seems tone-deaf. Don't try to truly heat your shop until it's insulated, set it for 45 or something. Save some power capacity for the rest of your state. Do your part.

 

[manwithtools]

This whole thread seems tone-deaf. Don't try to truly heat your shop until it's insulated, set it for 45 or something. Save some power capacity for the rest of your state. Do your part.

Roger that, it's a lack of situational awareness from my prospective. My building is not fully insulated and my heat pump won't keep up. It must be some one's problem other than me...

 

[slowtwitch73]

Funny thing is around here the old houses often don't have any insulation, or very minimal low budget stuff like cardboard or sawdust from the mill, and they more or less have been around many decades and given shelter through some pretty crappy MT weather. Go figure.

 

[ace10]

Maybe file a complaint with United Rentals?

 

[u3b3rg33k]

This is off a page for Goodman heat pumps.
A heat pump split system is an energy-efficient way to heat and cool your home year-round. Basically, a central air and heat pump system is an air conditioner that also works in reverse to heat your home in the winter.

If you live in a region with mild winters (mostly staying above 35 degrees), a heat pump system is the perfect way to save on your energy costs all year long. For those in colder regions, consider an AC/furnace system, since a heat pump will not be efficient during cold months.

I agree about the mitsu, it's the Goodman that is not efficient below 35.

unless that unit is really old that info is out of date. even goodman's cheapest system 5 ton pulls 3.25kW @ -5F and puts out 19kBTU.

that comes to about 11kBTU in, 19kBTU out, for a COP of 1.72, which is 72% better than heat strips alone. no reason to ever shut it off if you're using electricity to heat.



@OP, once you finish insulating, consider a thermostat that is "heat pump aware", honeywell makes some good ones. they will allow you to lock out the aux heat strips above an outdoor temperature you choose, so if you use a setback, or turn it on when you go out there, you can capture your savings/get your ROI on the install and still have the backup heat available when you need it. your wallet and the grid both win.

if you have roll-up steel doors, those are not great, basically uninsulated. if you can swap them out for traditional panel doors, then that's a huge wall of bare metal that becomes insulated (my door is literally styrofoam wrapped with steel for looks). you can get nylon brushes for the edges that will help with the air leakage, but it's the wrong kind of door if you care about keeping the heat out/in.

 

[finn]

someone please pull up a link to this thread the next time someone chimes in bragging how inexpensive it is to build a shop in Texas.

No or incomplete insulation, flimsy uninsulated garage doors, and doesn’t have a clue why it won’t retain heat. Luckily, there’s no snow load to contend with.

 

[Renegade1LI]

unless that unit is really old that info is out of date. even goodman's cheapest system 5 ton pulls 3.25kW @ -5F and puts out 19kBTU.

that comes to about 11kBTU in, 19kBTU out, for a COP of 1.72, which is 72% better than heat strips alone. no reason to ever shut it off if you're using electricity to heat.



@OP, once you finish insulating, consider a thermostat that is "heat pump aware", honeywell makes some good ones. they will allow you to lock out the aux heat strips above an outdoor temperature you choose, so if you use a setback, or turn it on when you go out there, you can capture your savings/get your ROI on the install and still have the backup heat available when you need it. your wallet and the grid both win.

if you have roll-up steel doors, those are not great, basically uninsulated. if you can swap them out for traditional panel doors, then that's a huge wall of bare metal that becomes insulated (my door is literally styrofoam wrapped with steel for looks). you can get nylon brushes for the edges that will help with the air leakage, but it's the wrong kind of door if you care about keeping the heat out/in.

It sounds good but below 35 degrees it starts blowing out cool air, there's a difference between efficiency and comfort.

 

[GMCGarage]

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!!

Neat.

 

[Dustball]

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.

The insulation aspect has already been discussed in this thread.

What you also need to take into consideration is that everything in your shop has thermal mass. When you're raising the temperature in your shop, it takes time for everything to equalize in temperature. For example, a heater will cycle a lot more in the first 24 hours than it would the second 24 hours if everything else remains the same.

 

[Crazyjake8493]

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.

Sounds like you need more insulation. I have the 7500 watt heater, but I run it on 5000 watts most of the time and it heats my 20x30 shop to at least 68-70 without running constantly. R16 ceilings, R13 walls, air sealed well. Upstate NY, so it get -10 to -15F at times and it still keeps up.

 

[Ak Jim]

Really it sounds like not only Texas but the entire south needs to have the building codes redone. There is a tremendous waste of energy even in the summer. If it takes so much energy to warm a place up 40-50 degrees then it also takes a lot to cool it 40-50 degrees in the summer.

 

[u3b3rg33k]

It sounds good but below 35 degrees it starts blowing out cool air, there's a difference between efficiency and comfort.

cool is a relative term. what's the discharge temp? delta T across the coil? room temp?

have you considered diffusers so you're not standing in the jet wash of a duct?

 

[MushCreek]

Sounds like you need more insulation. I have the 7500 watt heater, but I run it on 5000 watts most of the time and it heats my 20x30 shop to at least 68-70 without running constantly. R16 ceilings, R13 walls, air sealed well. Upstate NY, so it get -10 to -15F at times and it still keeps up.

I don't have any insulation at all in the shop. It's on my to-do list. I'm hoping I can find some kind of wall covering that's actually affordable in the days of $30+ OSB. Then I'll insulate and finish the interior.

 

[raco232]

This is the brush seal that is used on my roll-up door. Works great and am glad I installed it.

https://www.northshorecommercialdoor.com/brush-seals.html