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Help with sizing and position of heating unit(s)

Bill in PA

Hot Rolled
Joined
Jan 25, 2011
Location
Fairfield, PA
Please see attached drawing of shop.

I would like to install suspended electric heating units in the lower shop. I plan to purchase the TPI 5100 series units:
TPI HF2B5110CA1L 10KW 240V 1/3P/7.5KW 208V 1/3P UNIT HTR | Gordon Electric Supply, Inc.

I am unsure if I should get one large unit or two smaller ones, and what would be the best placement.

The walls, ceiling, and slab are insulated, although I cannot provide the R Value. Shop was built around 2000. The wall between the upper and lower shop is insulated as well.

Any advice would be appreciated.

Thanks,

Bill

Shop Layout.jpg
 
Last edited:
Please see attached drawing of shop.

I would like to install suspended electric heating units in the lower shop. I plan to purchase the TPI 5100 series units:
TPI HF2B5110CA1L 10KW 240V 1/3P/7.5KW 208V 1/3P UNIT HTR | Gordon Electric Supply, Inc.

I am unsure if I should get one large unit or two smaller ones, and what would be the best placement.

The walls, ceiling, and slab are insulated, although I cannot provide the R Value. Shop was built around 2000. The wall between the upper and lower shop is insulated as well.

Any advice would be appreciated.

Thanks,

Bill

View attachment 242666

Two, not one. Maybe even THREE?

Improved distribution of heat can reduce electric bills, and more than just a little. "Lower" shop ceilng-level stratification will "attempt' to make its way to upper shop as well, not to forget. You CAn actualy ut that to advantage, too.

I take that advantage in a three-level split residence, comfy bedrooms & baths top level, active LR, DR, KIT ground level where cooler temps are no mind, then a BR/study, flexible room, full bath lower ground floor.

Heat is re-used, and the HVAC air-handler applied to smooth it out when need be.

The garage/shop/annex with storage attic is actually a sort of fourth level, 8 inches below the lower-ground floor.

I like passive, no-fan ceiling-cove radiants better, actually. Migration in work to move off the older baseboard units, even in the residence areas.

Easier to clean in a shop. Less likely to see damage from carrying stock or such about than anything hanging can be. I have a useful but bloody nuisance strike-hazard ceiling fan as must go.

You might look at costs and do a hybrid, passive radiant/convection, plus the one fan forced air as an blender / booster, morning warmer-upper, then coast, mostly on the passives?

Those are about as safe, unattended, as electrics ever get for sustaining a reduced ration of heat, nightimes, and holidays-way, too. The ceiling cove mount reduces risk of crap - sometimes flammable - getting atop them as the old always-in-the-way baseboard mounts are prone to [1].

For your ones, the major plus is you can run on but the one when that works for you, and have it where it is NEEDED, not trying to economize from where it is not as helpful, too many feet of don't care space away.

Hurts me to say all that. I own rather a lot of Equitable stock!

:)

[1] With a not-too-disimilar space and a more Southerly aspect. my core level shop heat is actually the fall changeover from an array of Edison-base LED floods to ignorant 150 Watt Incandescents, left on 24 X 7. OTOH, my insulation is approaching silly high R-values.

Or so I once thot, when juice was cheaper. Makes the summer A/C right cheap, too, though.
 
If its got nothing else now. Then, 1 of those electric heaters as back up heat, and a Ductless Heat Pump as main heat and AC. A 18kBtu unit can easily heat/cool a 25x32 shop, way more energy efficient and in the US you can buy and install them yourselves and save a lot of $ vs the ridiculous price installers charge to do a half ass job most of the time...
 
That L shape creates problems in the heating layout with air flow. I would probably put one in the corner west of the office door, blowing toward the garage door. The other I would place on the south east corner of the office wall blowing toward the north east corner of the room.
 
If its got nothing else now. Then, 1 of those electric heaters as back up heat, and a Ductless Heat Pump as main heat and AC. A 18kBtu unit can easily heat/cool a 25x32 shop, way more energy efficient and in the US you can buy and install them yourselves and save a lot of $ vs the ridiculous price installers charge to do a half ass job most of the time...

An air-to-air heat pump has a great deal of merit, Mid-Atlantic "coastal plain", his location. Or my own.

They have come a very long way to "JFDI" wire-and-forget since my first one, early 1970's, a highly problematic "Amana" that I grew short-tempered with and eventually had re-engineered by a friend who was our commercial large-retail building HVAC contractor. After Norm's team "breathed heavily on it" with better components and controls, it ran about 15 years, no further hassle until the female back of the thermostat was no longer tolerable!

:)

Lo these many years on, even Chinese factories are building more of them proper-like to begin with, the next-door neighbour's premium-end Lennox split/plumbed system a real gem and uncanny quiet as well.

The larger of the two sections on my own plate has an 18-foot wide vanilla panelled-roll-up "garage" door. Now and then there is the "recovery" challenge when the entire air charge is swapped-out for ambient outdoors.

Hence my preference for "radiant" heat. That heats the air as a byproduct of first heating the "things" IN the space. Slab, opposing walls, and all the massive "Old Iron" residents come up to temp and act as flywheels.

Forced air units, any heat source, do the reverse. Heat the air first, the "things" in the space warm gradually as a byproduct of the temperature of the air.

Swings and roundabouts over enough time to stabilize, but the radiant is more comfortable, SOONER, wintertimes, for he who has to work in the space, as it resembles sunshine sourced heat.

Conversely, summertimes, "radiant" not even an option, forced air cooling is more comfortable, SOONER anyway as the breeze off even a fan works with our own natural "cooling system" skin, even sweat.

Complicated or costly to gin up a hybrid system for relatively small spaces?

Not really.

This past summer, I experimented with two GE-branded, 5,500 BTU uber small and light 120 VAC window units. Only $120 or so each and mere minutes to install, since remove. At those prices? Why would I not do the trials?

Lesson Learned? They "peak" well-enough to improve per-room comfort when used at all, but "peak" they or follow-ons shall become. No surprise that their operating efficiency is rather poor.

Keeping my year-round costs down relies on an undersized central system run steadily at its peak efficiency, spot-augmented with less-efficient to run, but cheaper to acquire "boosters" put online only when there is a genuine need, ELSE NOT.

Insulation, and lots of it, plus control of air in/out, not accidental drafts, is still by far the most important money-saver of all, and the "enabler" of any and all of those other choices at the more affordable costs.

Works for me. No "black magic" to it.

All the info is online, plenty of sources. Mix and match can pay-off.

Add a ration of solar if you can do as well, and not necessarly photo-voltaic.

A bit of sensible heat - residential full or partial water heating, or "taking the chill off" a secondary-use space, for example, can be easier and less long-term hassle than electricity.

After all - cold frames and greenhouses worked even for Grandparent's farm, 1912-1954 with no electricity at all that didn't come off a battery. Natural gas wells, rather!

:)
 
Considering those emit the heat of five 1500 watt electric space heaters I think I would go with 3 of them. My shop is basically the same size I just park portable kerosene and electric heaters around mostly to keep the machines warm. If I had them all fired up they would probably add up to two of those you are looking at. If they were all evenly spaced not a chance it would be enough to get the whole place out of the high 50's on a cold winter day.
 
Considering those emit the heat of five 1500 watt electric space heaters I think I would go with 3 of them. My shop is basically the same size I just park portable kerosene and electric heaters around mostly to keep the machines warm. If I had them all fired up they would probably add up to two of those you are looking at. If they were all evenly spaced not a chance it would be enough to get the whole place out of the high 50's on a cold winter day.

They "emit the heat" at electical goods ga-ron-teed net 100% efficiency, but.. They also have to EAT out of your pocketbook to do that. Seventy Five Hundred Mike-Foxtrot Watts at full-gallop? I'm driving the entire place to less than half that as a goal, and nearly there, already

Ten or fewer degree "EFF" outdoors here? ONE 1000 W and ONE more 1200 Watt wheeled DeLonghi electric/oil wheely per side added to the overhead lights, and temps stay around 40 F. Another 13 inches of unfaced FG already dragged up there get laid in the attic, that will be warmer yet.

Insulate, Brethren. INSULATE. Done that, already? Do it again, even better.

It pays back "at once" in comfort, same hour and day it is installed, and all year 'round a century and more thereafter.

Then more slowly, but for-damned-SURE even in MONEY!

Everything else - I repeat EVERYTHING - is left to fight over SECOND place winner, at best.

SECOND place here, BTW is reducing the need of "pay for it" external energy altogether. It is a "back to the future" of GREAT G'Dad's day - before even we had the gas wells and chopping wood or even gathering "free" deadfall was meant to be minimized for lack of time to waste at it, plentiful supply notwithstanding.

Six near-as-dammit due South facing widows undraped to capture winter sunshine, heavily draped at night. Reverse the timing, summer heat of the sun.

Nightime / wee-hours air encouraged to cool at summertime cuts the air-con bill, and gives much nicer air as well.

Simple stuff, yah? Dead simple, actually.

Our ancestors lived rather well off basic common sense, no utility grid in existence, first several hundreds of thousands of years, arredy, yah?

All that "natural" s**t still works as well as ever.

We've just gone too damned bloody-minded indifferent for too damned long to even remember just how well it can work, and close to "for free", yet.

I'm healthier and more COMFORTABLE than ever, year-round.. and yet?

More than half of what USED to feed Dominion Virginia Power has been buying a lot of nice tools for my shop, several years running, now. Machinery and tools - even steak and nicer shoes and clothing - instead of DOM VA receipts?

That sort of "found money", and enduring, be motivation enough to get your attention?

Thought it might be...

Just apply some of the same high-level problem-solving skills, wise planning, and precision we each enjoy putting into our WORK onto the spaces in which we live and DO that work?

It pays off nicely. It can last a VERY long time. Sweet comfort in old age, "Security" even, and cheap SE grins and the odd BRAG, about it, too!

:)
 
I think you'll be fine with one. My shop is 1200 sq ft. I run at 10kw heater (actually part of my A/C unit) or a 5kW space heater. The bigger one will get the place up 10 degrees in a couple hours and my ceilings are 17'. I wonder how well sealed the 12' door is.
 
You don't specify what temperature you're looking to maintain and whether it's full time or part time. Maintaining 55-60 should be easy, 75 much more difficult with an overhead door. Make sure that door is as well sealed as you can get it.

If it's full time you'll definitely be money ahead after a couple years to put in a mini-split heat pump and a smaller electric unit. PA also gets hot and humid in the summer so AC would be a bonus there. If it's part time heat only I think one of those units would suffice for that space. I get by with less in Maine in a poorly insulated garage, but I'm heating to like 50 not 70 when I'm out there.
 
You don't specify what temperature you're looking to maintain and whether it's full time or part time. Maintaining 55-60 should be easy, 75 much more difficult with an overhead door. Make sure that door is as well sealed as you can get it.

If it's full time you'll definitely be money ahead after a couple years to put in a mini-split heat pump and a smaller electric unit. PA also gets hot and humid in the summer so AC would be a bonus there. If it's part time heat only I think one of those units would suffice for that space. I get by with less in Maine in a poorly insulated garage, but I'm heating to like 50 not 70 when I'm out there.

I have been using kerosene for the past six years and am sick of it. I am considering a mini-split as a future purchase as I cannot swing it at this time.

I currently keep the shop at 68-70 during the winter and summer (AC unit works fine).

Thanks,

Bill
 
I have been using kerosene for the past six years and am sick of it.

AC already covered? Give a thunk to just driving down the kerosene use one affordable increment at each go until DONE day arrives a year or three out:

Concept is here, they are not the only story worth a read as to shaking the shit off the claims, but they are not wrong, either, and a fan cannot fail if it doesn't even exist. Quiet, too, those non-existent fans!

:)

Electric Wall Heaters | Electric Radiant Heaters | Radiant Systems Inc | Radiant Systems

Prices here. They have competition, and plenty of it:

Cost Effective Heater | Comfort Cove | Radiant Systems

Not a lot of money, time, or awkwardness involved to run a circuit and hang the first one, wire it and see how it works for YOU.

Decently, even if sub-optimal for open high rafters and zero insulation up-top is my guess. Better yet you DO have a closed overhead and at least modest insulation arredy.

With the "other home" in Hong Kong?

I'm full-bore paranoid about safety, unattended dwelling. Mine are being zone-backed with sheet aluminium, Rock-On sand-cement, not vegetable fibre board to insure any overheat or sparky-drama remain contained in the metal, AND NOT, repeat NOT into the joists of the floor above.

House here was built, early '70's, with the bloody-nuisance "baseboard" heat, each room. Work better than they look, of course. Roughly half the units are still the originals, too. "Singer" tended to do stuff durable-like, anything they ever touched.

Getting similar goods TF off the floor will be a Godsend, all counts. Can't run potentially flammable draperies atop 'em, melt a plastic dustpan, smolder a paper towel or cleaning sponge forgotten in-place of a cooler month. BIG plus is that they will no longer interfere with where furniture can be placed.

Wall/ceiling cove is just as handy, typical shop vs need of clear space and flexibility of use, damned near everyhere else, yah?
 
I have been using kerosene for the past six years and am sick of it. I am considering a mini-split as a future purchase as I cannot swing it at this time.

I currently keep the shop at 68-70 during the winter and summer (AC unit works fine).

Thanks,

Bill

Bill, I'm not being a wiseacre...if you can't afford a minisplit you can't afford to heat a shop constantly to 68 degrees with electric heat. With that overhead door you're electric bill is going to be through the roof. Your proposed heater will likely cost you more than $1/hr to run depending on your electric rate, maybe as much as $1.5/hr. I'd predict a $400-600 per month electric bill.

You're also proposing an $800 electric heater, maybe two, so you're almost to a minisplit as it is. You can get an electric heater for much cheaper if you really want to go that route.

Anything over 60 degrees is too warm for a shop in my opinion, and you'll save a ton of money between 60 and 70.
 
Anything over 60 degrees is too warm for a shop in my opinion, and you'll save a ton of money between 60 and 70.

Surely so wintertimes. I detest sweating if I can avoid it because.. I have to consciously command it to HAPPEN!

Serious heat-stroke hit me hard long time ago and the body has had to be under "rudder amidship" and local steering by a damage-control party like a badly crippled warship ever since the automatics got fried.

Give me 55 to 65 EFF and a watch cap on or off the bald d**k-head for fine tuning of comfort and that's jest fine when active.

Sittin' room & sedentary? Good wool sweaters. Scots, Irish, or English style. China's own "Cashmere" Snow Leopard brand. ELSE Australian, most often.

Cooler homes cut down on respiratory bugs VERY dramatically, too. That learnt from a Mersyside-born G'mum as well.

Brits think yanks are insane for overheating homes at wintertimes, and they are not far wrong. Its the health. Not just the cost.

They don't bear even a fraction of the chronic colds and sniffles we average, lower 48. Never have, either, even same genes or same PERSON, transplanted, either direction - and a thermostat dial adjusted.

Learn from that, Brethren. Or keep making the NyQuil and kleenex kings richer, yet.
 
Bill, I'm not being a wiseacre...if you can't afford a minisplit you can't afford to heat a shop constantly to 68 degrees with electric heat. With that overhead door you're electric bill is going to be through the roof. Your proposed heater will likely cost you more than $1/hr to run depending on your electric rate, maybe as much as $1.5/hr. I'd predict a $400-600 per month electric bill.

You're also proposing an $800 electric heater, maybe two, so you're almost to a minisplit as it is. You can get an electric heater for much cheaper if you really want to go that route.

Anything over 60 degrees is too warm for a shop in my opinion, and you'll save a ton of money between 60 and 70.

Your thoughts are appreciated.

I expect the costs to be high, at least relative to what I have been spending for heat. I normally use an average of around 5-7 gallons of kerosene per week for heat from November through March.

I have seen that electric heaters can be had for considerably less money than what I have chosen. I am skeptical of the quality though. I like that the TPI models flow more CFM than the cheaper ones and they also come ready for low-volt thermostats.

I did evaluate propane heaters. Propane is over $3/gallon here. At $.085/kWh (total bill/kWh used), my calculations indicate that electric is a bit cheaper.

Thanks,

Bill
 
I did evaluate propane heaters. Propane is over $3/gallon here. At $.085/kWh (total bill/kWh used), my calculations indicate that electric is a bit cheaper.

A trend likely to continue, even as absolute costs for ALL fuels rise.

Dom VA Power is one of the older "proofs" that the most affordable "battery" is pumped water storage.

Smith Mountain Lake / Lee Lake and back-pumped by the nukes at Lake Anna in off-peak times, for long, long years, already.

Meanwhile, back at the reality of mobocracy influence on regulators - "Three Mile Island" close to home, Japan or Chernobyl nastier by far. DOM VA and other major powerco's are building out massive solar arrays, as they are probably not even going to TRY for licensing of follow-on nukes.

The grid is largely "there, already" and where and from WHAT the source of the energy put INTO it of less import than the historical incumbent's commercial advantage as to the DELIVERY of it, your patch, my one, or anywhere else "on grid".

Beside.. not hard to put yesteryear's kerosene into "fallback mode". Short-term power outage. Or mid-term MONEY shortage. Either one. And more.
 
One, your shop is not in Texas so different needs.
Two, air flow CFM means nothing, you can move air around with 12 dollar fans. The heat output (BTU) is the only factor.
Electric is the only way?
Gas infrared tube style overheads out of the question? Even on a propane tank I'd consider this option.
Anyhoo the conversion from electricity to heat is about the same across all heaters. Heat at the ceiling level does you not so much good so fans .
Bob
 
Please see attached drawing of shop.

I would like to install suspended electric heating units in the lower shop. I plan to purchase the TPI 5100 series units:
TPI HF2B5110CA1L 10KW 240V 1/3P/7.5KW 208V 1/3P UNIT HTR | Gordon Electric Supply, Inc.

I am unsure if I should get one large unit or two smaller ones, and what would be the best placement.

The walls, ceiling, and slab are insulated, although I cannot provide the R Value. Shop was built around 2000. The wall between the upper and lower shop is insulated as well.

Any advice would be appreciated.

Thanks,

Bill

View attachment 242666

Maybe doing stuff like that is different in the USA but here I'd ask 2 or 3 companies that specialize in that kind of thing to come and give the place a look over and come with a suggestion and price estimate.

From personal experience I know they might even come up with something you haven't even considered. Just heat but no cool?

I doubt if anyone can give you the best advice without seeing your place IRL.
 
One, your shop is not in Texas so different needs.

My last shop was in a garage in Iowa. Winters were worse than PA (I've lived there too). They cut all the trees down to grow corn, so the wind cuts like a knife. I had that 5kW heater and it kept me ok in 300 ft^2. I'd only leave it on at night when it was really bad and didn't feel like starting sub 40.
 








 
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