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At 7 minutes starts at COP
https://www.youtube.com/watch?v=kJnHeNpNU1E This may help https://www.youtube.com/watch?v=irD6Sj0KRrk |
For those curious of the COP values at different temps
This chart gives a good understanding of what COP value your getting at various temperature , the COP rating on a Heat Pumps label is not its Maximum COP https://originaltwist.files.wordpres.../cop-graph.jpg In warming weather the COP climbs , cooler it lowers but still makes decent COP numbers until its too cold then a new heat source needs to be employed. I have little idea how this applies to the Portable one hose heat pumps. I think it may keep a steadier COP and work a little bit longer to heat the colder intake / infiltration air |
Ok, let me clarify a bit. In a sense, both ormston and I are correct. The design looks horrible on paper. A traditional split system has all this latent heat flowing straight to where you want it. You can make a cool looking graph and calculate everything distinctly. The one pipe looks messy and super leaky and ineffective when you plot points and make diagrams.
The one pipe setup is a heat pump, just not a traditional or "proper" design. It isn't going to start from scratch and heat up a cold room quickly. The analysis on paper leads engineering types to believe that it won't do it's job very well. After all, there is no such thing as a free lunch. However, the rig does its job well for the price and size. It is meant to be a supplemental heat source (or sink) anyway. When you put it downstairs or in a cool, dank basement, and it is cool or cold outside, the make-up air tends to fall towards the unit. This cooler air is heated and then rises to the ceiling and finds its own way up. The utility of the unit comes from its ability to exhaust comfortable warm air inside the envelope in large quantities. Unlike a standard heat pump, this rig will keep pouring out the same temperature air when it gets frigid outside. Rather than using it's leverage to move raw Watts from one place to another, it extracts what you don't want (heat or anti-heat) from the indoor air and exhausts the waste outside. This is where the unit can fool you if the whole premise is not considered. As others have stated, when it gets cooler outdoors than the exhaust air, the unit loses effectiveness due to the incoming make-up air. When a standard air source split unit starts losing efficiency, the condenser temperature drops and so does current draw. The one pipe setup will continue to draw the same power and the same temperature air will be spit out indoors. In most situations, by the time the outdoor temperature dropped to this level, the one pipe system would not be able to keep the cold from creeping in, even if it was a split unit. Being under a ton of refrigeration capacity, it has its limits. As the Delta T between indoor and outdoor air temperature rises, the primary heat source will be called upon more and more anyway. If saving money is s major concern, a low ambient control could be rigged to cut power to the unit below a certain balance point. FWIW, the Sub-Zero hyper heating air source mini split units act the same way: they force a higher indoor discharge temperature by speeding up the compressor. This lays waste to the COP of the unit. Useful heating is still achieved, but at great expense. |
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This concept doesn't have the same measurement metrics as a traditional heat pump. Let's say you have the unit in a low spot in the home near a window. If you crack that window open just an inch, your make-up air will all come through that opening, and find the intake of the unit. The unit will find a new balance point at lower COP, but the warm air will rise up and away from the unit, and the rest of the home will (hopefully) hold more heat. Factor that one in on paper. |
Thanks for further input were getting this nut cracked.
The arrangement It will be exhausting cooler air out from the rec room floor via a low sucking cardboard vent attached to the side intake extended down near the floor to gather and expel the coolest room air and cycle the upper warmer room air for heat to drift upstairs. It will be set 3 feet off the floor so the indoor fan will cycle the upper warmer air threw the indoor fan. The temp The temp difference from floor to 5 feet above might only be a 5* or 7* difference ( yet to be tested) but should still help its economy. Every teak will help when its running 12 or 18 hrs a day on cold nights Its 31 inches tall so when placed on a table to vent straight out , the room fan will draw air from about 65 inches off the floor or 5 1/2 feet. ~~~~~~~~ Tests Today have been studying on fan speeds comparing the top name mini splits factory rating to a independent tests chambers results . The results were similar to advertised I found that with the compressor speed set on high the best COP at any temp was made with the Fans on high as well. Because this unit has non inverter compressor it runs at full speed so the highest Fan speeds will provide the highest COP. I should swap the 4 inch Vent plate for a 6 inch vent and gain the airflow COP it should provide. The stove vent outlet plates cost $40 so it makes fiscal sense to swap it out to get the units maximum COP rating. The last tweak I can think of a HRV but is too expensive at near 1000 dollars but I like the idea. The basement and front doors both leak air the stoves overhead fan vent leaks 24-7 so most of those drafts will be used as the intake air for the exhaust. With the unit running it will reverse the airflow instead of flowing out the cracks it will come in and out the AC although at a higher rate it at least will draw from the houses current losses. I think its going to work out pretty well in this case If you think of affordable tweaks let me know I'll try them out. |
More food for thought
The units 1200w of input power to the compressor stays in the house as heat after its done its work.From what I read that will provide a 20% bump in heat output A lot of the complaints with a indoor one hose AC's doesn't effect the units as much when in heater mode. As a one hose heater It works in its full COP cycle 24-7 It rarely will need a defrost cycle Its air input draws from current warm air leaks cutting incurred losses further The Compressor 1200w of power consumption heat stays in the house not outdoors like a mini split design. Last but not least natural convection will flow heat up where its required instead of trapping it in the room Its actually not as bad of a heater as it first appears |
My last mind bender is how they rate the Btu / COP output.
Could be its measured Btu output done at room temperature or 44*f It seems mini split manufactures use around a 7*c / 44*f outdoor temp to rate the COP values. Possibly to get the fixed COP value they factor in the infiltrated air I can't find info on how Honeywell or anyone Rates these units to a Btu output Could be the Btu value is a factored value taking into account the outdoor 7*c / 44*f infiltrated air temp Or its rated Btu output is for the indoor temps they are expected to be in. Its low priced so it may pull off a COP of 2.7 maximum at room temp. That also makes sense as its half the costs of the cheaper of the mini splits The model is Honeywell HL14CHESWW Its 14000 BTU cool output and 11000 Btu heating output suggests to me they have done factoring into its rating or it might just be the condenser size that changes the values between heat and cool. I dunno |
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I see why now , remember reading that they measure COP in heat pumps by the inlet and outlet temps / indoor heat gain vs outdoor air temps. So this units COP *should* be a accurate representation of its efficiency at around 7*c / 44*f or there about like with the outdoor splits COP measurement That makes sense or the Btu numbers are next to useless / a advertising stunt. It might not be 100% accurate but should be in the realm of its heat output COP @ 44*f outdoor air temps I'm not sure of that but it sounds reasonable Edit I read the last statement wrong " The system COP will follow outdoor air temperature minus exhaust air temperature " That throws a loop into my theory I thought I would measure outdoor air as the inlet and Btu heat as the outlet temperature its sounding like a reverse COP math I should be able to figure out Btu gain at 44* (or there about) with this system like with a mini split. New math plan I'll keep it simple and follow what was wrote above in the highlighted area Lets say its 7*c outside and the vent blows out 2*c , divided is 3.5 COP I'll try it again with more numbers 12*c divided by outlet temp of 2*c = COP of 6 Might be onto something I will have to take real numbers when its running and see what those are That math my well be totally wrong Im far from a HVAC guy Edit I need to convert it to Kelvin first 12*c to K = 285 7 to K= 280 2 to K= 275 COP @ 12*c outside and 2* from cold outlet = 12 - 2 = 10 COP 7 - 2= 5 COP I'll try that with real numbers when I have them and do more research in the meanwhile |
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Basically the Unit brings in outdoor air at say 72ºF and discharges it at 32ºF, so basically there are 40ºF worth of BTUs in that infiltrated air. If we want the indoor air to be 76ºF then 10% of those BTUs are used to heat up the infiltrated air and the rest of the BTUs are used to heat up the rest of the house. COP is the efficiency of the Unit itself not a measure of efficiency of the entire house. Basically the unit can cause a net loss of heat to the house (this happens when the recoverable BTUs are greater than the BTUs needed to warm the infiltrated air up to warm temperature) and the unit will still operate at its COP. |
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I agree , that fact took awhile to sink in but jeffmay finally got threw to me
Was hoping to use it in the coldest months of the year but I had it wrong ! Like you wrote Its the inlet vs outlet temps that ultimately determine the units net gain / loss. Its scheduled to be here on Friday / tomorrow by the end of the day so soon I'll have its outlet temp to compare. These portables are widely know to be crappy performing AC's, from consumer reports to everyone in between. ( beside anecdotal evidence from people who find they worked for them ) I have not found anything about its heating performance its likely the same as its cooling maybe its slightly better who knows until you try. If it works as in heats up the house it could be same as the wattage it consumes and I would never know. As it is I can run a ceramic heater downstairs on 500w and it heats the upstairs on most days. The unit runs on 1200w so it might look good to me but have no real savings. I can though compare the past 10 years of hydro data to its energy consumption. if it changes little that means there no net gain for me. The inlet / outlet temps will show me whats possible with the unit anyways and whats not. |
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The highlighted paragraph is what I was thinking from the start (I think as Ive been learning along the way) The math works and explains running the unit indoors will show gains. Reliant on the outlet temps vs outdoor temps of course. Thanks DEnd for the good clarification |
The ac unit was just delivered I'll leave it sit for an hour and run a outdoor vs outlet temp test using the 6 to 4 reducer and post its gains in mild weather , its currently 15*c / 59*f @ 10 am with indoor the electric heat set at 19c / 66*f
Side note may well leave it on the straight through tapered 6 to 4 reducer. All things considered it may cancel out differences in the infiltrated air vs Btu heat gain and can't be much worse then the 6 inch with two 45* bends most people set them up with ? Not really sure how that would come into play as far as net gain. Update its plugged in blowing in free space while I test its watt draw and air flow , it blows more air out the back then I would like using my hand as a gauge. I will test the outlet airflow and the differences between now. Watt draw was 610w at start up 10 minutes later settled between 1057w to 1060w with a starting room temp of 19*c / 66.4* that moves it from a 2.7 to a 3 COP |
Im trying this again
Wind speed out back of unit = 20 mph wind speed out the 6 to 4 inch reducer = 25 miles an hour Converted to CFM 6 inch duct = 345 cfm 4 inch duct = 191 cfm = 45% reduction Looks like the internet fooled me , its probably 241 cfm out the duct work not front circulation fan. I will test with ducts in place and take wind speed measurements from the outside vent when its plumbed. This math is looking weird and I used this online calculator here > Air Flow Conversion Calculator - ft/meter, m/s, miles/hr, ft3/min, m3/hr, L/s I will make a youtube Video and try to educate people about this thing once I have it tested , and Im wondering how /why would people as in the whole internet got the output flow WRONG ( me too) Mind you when people said it made a lot of negative pressure they were Right :) it will a beastly amount. It will reduce flow further by plumbing to the 4 inch back draft vent / dryer vent so it *may* fly yet. I'll test the plumbed ducts outlet flow and call it a close estimate as the numbers pretty much match so far with its 241 cfm rating. I feel a little burn off those numbers but will try this little beast anyways no sense quitting now ! |
Its plumbed and running , the outside exhaust outlet front edge reading was 21 to 25 mph the middle around 17 gives an average around 20 mph the same as the 6 to 4 adapter average 154 CFM (or there about)
The iPhone makes for a tricky post ! http://ecorenovator.org/forum/member...cfm-outlet.jpg 0.3*c outlet temp 16*c / 61*f inlet (outdoors) plumbed the hose and taped it tight http://ecorenovator.org/forum/member...aped-tight.jpg Exhaust is wrapped with a old mummy bag then plumbed it to drain condensate in a water cooler bottle. http://ecorenovator.org/forum/member...ghs-85-lbs.jpg Weighs 85 lbs Set to blow hot air up toward the doorway Tomorrow will make the cardboard vent and block the middle of the doorway to get flow separation.Have not noticed a back draft yet , there is no door hung Temp downstairs was 29*c or 84* upstairs 24*c 75*f Had it set a 87* to test. Upstairs can just hear it turn on/off , down in the room its a pretty loud low frequency sound with a added compressor note. Inlet ? outlet tests done at about 6 pm 61* / 16*c outdoors infiltrating air 32.5*f / 0.3*c house exhaust taken from the exhaust vent outside the house. Hot air vent was 145* to 140*f or 63* to 61.5*c Tonight's low prediction 8*c / 46.5*f the weeks average is 5.5*c Do single phase compressors make their highest COP at real warm temps too ? Read they made cop 5 from about 10*c to 12c not sure if it includes higher temps as the chart was unclear. I read 3 phase make theirs highest cop up at 35*f ? due to low compressor power draw. Thats what some pdf file says anyways , The pdf link https://r.search.yahoo.com/_ylt=AwrT...naWE__qpgicvk- |
I ran it for a for a few hours this morning it heated the downstairs room to 29*c but did not change the upstairs room temperature its Vacuum was too strong.
The only way it stands a chance of working is if the hot air is vented upstairs. There is a 15 x8 or something rectangular vent on the rooms ceiling used for when the pellet stove was there. that was vented to the kitchen floor. I patched it and covered it with wood flooring. Don't think this thing worth cutting a vent back in it. Short of throwing in the towel it could be hacked into a mini split. I'll take the cover it off and see what could to be done later tonight Or maybe just return it Here is inside a filthy ac https://nettts.com/wp-content/upload...36490624-1.jpg http://www.climax-air.com/dual-hose-...c-capacity.jpg |
I double checked using a box fan in the top of the doorway and even with it going the upper floor does not heat after a few hours while the basement room broils at 39*c
Moved the unit outside to run tests Test conditions 1 hour run time 5 readings taken in 10 minute intervals Outside temp started at 8*c at test end was 10*c Cold air vent -3*c on the fan wheel down to -10* from the center of the vent screen Hot air vent 40*c to 45*c depending on where in the vent the reading is taken Did not notice a defrost cycle The show is not over yet its mod time As the saying goes "If at first you don't succeed try try again" Round 2 Dual 6 inch ducts http://ecorenovator.org/forum/member...nch-intake.jpg Sealed two layers of cardboard to the vent and resealed it with a 3rd layer over top http://ecorenovator.org/forum/member...evaperator.jpg http://ecorenovator.org/forum/member...-cardboard.jpg It was easy enough to do used the filter cover for a template trimmed the cardboard with scissors cut 5 3/4" holes with a knife and taped it tight with tuck tape. |
Ran a overnight test using the auto temp control it maintained a house temp of 19c consuming a average of 470 watts per hour or just less then half its 1050w draw.
a 45% duty cycle , outside temp 6 to 7c / 44f So I will be cutting the vent back in the kitchen floor to vent warm air with a Air king 200cfm 1.4 sone fan mounted in the downstairs rooms ceiling. Right now a box fanis in the downstairs doorway to cycle air in and out , it works. Its pushing out the heat with vent temps high is 125 to 130F with a low of 115*F at 40 to 44f. Before the next few days are up will make a air filter box with vents to secure the hose ends. Thinking will use a can or two of spray foam to insulate the vent with. |
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Looks like i read in a post that you were using a space heater somewhere. May be cheaper to l let that unit your bought topickup that extra heating for this heating season. Until you can put it on the market. I looked and found my old post when i bought my cheapy mini split . (still chugging along) http://ecorenovator.org/forum/geothe...ini-split.html |
Ok, so the thing is blowing out Sub-Zero exhaust pipe air at room temperature supply air? Awesome! Good to know the rig puts out nice warm air. More useful heat and less power draw than a hair dryer heater is good news.
What I ended up doing with mine to keep the exhaust pipe air colder than outdoor temperature was to choke the evaporator supply air. I just put a filtrete air filter over the inlet grille. That little bit of restriction gave me about 5 degF outlet air. Like I said before, by the time it got that cold outside, the gas blast furnace was running anyway to keep the house warm. |
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Told myself to wait until the house repairs are finished before spending money on one of the eBay Senville heat pumps. About $1100 for a 12K plus install fees and assorted material expenses would not be surprised to pay $1700 total Curious what you payed all in for your Split ? , I will follow the link and see the install etc , thanks ! |
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So far with the intake hoses out the window its been working well still have not tested the outside vent temp the units in a off moment now or could test it. It should be the same as the readings was getting with the unit running outside. The heat output has been steady at 46c / 115*F front outlet temp with a 7c inlet temp and a 24c room temp that gets blown threw the hot side. The cold side is straight outside air in and out. Ive noticed it does a auto defrost when needed so far noticed thats in the morning when its still foggy out and in the evening after running for awhile but it drains much more often seems to drain water without loosing heat output most of the time with a few real defrost cycles thrown in here and there where the hot side cools. |
Might of figured out how to identify the Btu gains
The Btu gain conversion calls for the Fan CFM x 1.1 x difference in inlet vs outlet temperatures. Using the hot side temps to measure gains seems to work Room temp of 75f minus by the Hot side of 115f = 40*f gain Fan 240cfm x 1.1 =264 x gain of 40f =10,560 Btu The unit is rated to make 11,000 btu If the hot side in/out numbers are used as the the inlet /outlet temp the math works. Using the cold intake temp of 44f vs the 115f hot outlet with the above math shows a 19,800 Btu gain. I doubt that right. The only numbers left are the cold sides in/out of 44*f in / 14 out with a 240CFM fan that math shows a 7920 Btu gain which is closer to the hot sides result |
The Defrost Cycle
During the defrost cycle both front and rear fans reduce / ramp up / auto shut off as required. The front outlet temperature starts to lower as the defrost cycles kicks in eventually reach 95*f in the end reaching near room temperature at that point the unit starts to drain melted ice in a little stream of water for 3 - 5 minutes during that period the watt draw reduces to a low of 450 watt holds for a few minutes and ramps up to 550 watt the ice is still melting during this period and the front fan is off with a slight breeze leaving the rear vent. When it enters the later stages of the defrost it flashes the sleep mode indicator I figured out that anytime the unit is dripping water and blowing hot air is because a defrost cycle has just ended and its beck to making heat. Tested the defrosts after it finished a defrost cycle by switching the unit into cool mode reversing the valve and it did not melt anymore ice. Outside temp 3*f Humidity 70 -100% mostly 100% Be nice when the humidity drops it should improve it cold weather performance |
portable ac cold weather test
First cold weather test
Last night it maintained a house temp of 18.5*c with the outside temp a few degrees above freezing. Temp was between 34.7 and 35.6*f , 1.5 to 2*c the added workload increased the duty cycle by 10% (from 50 to 55% ) my assumption is the added time was spent defrosting as noticed its been defrosting more often. It heated with 35*F overnight temps ! |
portable ac heat pump
The ventilation fan arrived and was plumbed up in the spirit of portability despite its large 12 7/8" x 12 3/4" x 10" size and 17 lb weight its easy enough to move.
Model / Air King AK200LS 1.4 sones , 200cfm Its intake is facing the ceiling to vent the warmest air http://ecorenovator.org/forum/member...h-upstairs.jpg Speeds: 1 Design: squirrel cage Continuous running: yes Power rating: 60w Actual draw: 43w Fan noise s reported to be 1.4 sones that increases proportionately to the pressure or restriction put on it. I noticed the fans noise increased after being plumbed to 20 feet of flex duct with two 90* bends. Its still much quieter then the AC The AC was moved from the left side near the vent over to the right side with window access. http://ecorenovator.org/forum/member...lumbed-out.jpg Its the first day with the vent so far I can say the upstairs has warmed up 1* and its nearly silent upstairs except for the low whoosh of warm air leaving the flex pipe at the top of the stairs. The downstairs room is 17x11 x8' = 1400cu.ft the fan will be left running 24-7 to maintain thermal continuity between the upstairs and down. In closing The next weeks weather is wet and warmish with 10c average temperatures and 100% humidity along with fog. That weather makes for more defrost cycles but so far unit deals with it without issue. |
To improve the performance finally added a duct from the ac to the 200cfm fan and straightened out the duct run.
http://ecorenovator.org/forum/member...xhaust-fan.jpg Before the added duct upstairs was 80 degrees after 20 minutes now its reaching over 100 quickly and maintaining it for an hour. Will be readjusting the AC's thermostat to find its new balancing point http://ecorenovator.org/forum/member...80-degrees.jpg This is at the top of the stairs where a splitter was added to reduce the air speed. 100 degree air feels real nice much nicer then 80 degrees which is not bad Before the downstairs room would reach 24c /75F while the unit was running while the upstairs was 20c /68f , now the downstairs room has been staying at 20* http://ecorenovator.org/forum/member...ug-opening.jpg For winter heating bought a inkbird 308 temp controller it has a switch for heating and cooling. With it can set the exhaust fan to shut off when the vent temp drops / the ac goes off and have it turn on a ceramic heater upstairs at the same time. This way I will have heat going 24-7 if needed and at no more then 1000w and hour. Thats the goal , to heat the house on 1000 watts of energy this winter. So far Im using 500 watts an hour for heat. The kill-a-watt meter makes for easy record keeping the ac has been running on a hour on hour off cycle on auto some days running 4 hrs less some days running 4 hrs more. It always balances out at 50% off 50% on. The other night it ran for 6 straight hours it does what it can with the weather its got. its been wet and warm lately with a 10c average. For now its clear sailing won't see cold temperatures until the end of December |
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Im using the AC in dual hose mode now and its been running with night temps between 3 and 8c regularly. Its been on the kill watt meter for 505 hours , its working out to run 50% of the time 50% off for a average of 500w an hour.
That costs me $35 a month I want to use $70 to $75 on heat and $25 to $30 on utilities for $100 total electric costs not $100 on heat as I typed earlier. So I can double the current heat out put Im using now to heat with a average outside temp of 10c the winter lows are usually 0 to -1 or 2c Be nice if it squeezes heat out of the air still when its below zero Im hoping it does as that's the time it can reduce electrical consumption the most http://ecorenovator.org/forum/member...nch-intake.jpg |
If you have the means, please try to log your energy usage over time. There are still people who believe that what you are running doesn't save anything. I know this rig isn't a full size heater compared to a whole home blast furnace, but not everyone has a large home to heat. These units were made for supplemental applications anyway.
Take a look at some of xringer's threads. He does an awesome job at keeping track of the power usage of all kinds of equipment over time. He piggybacks his climate data with weather underground and details the operation of specific rigs to give others more insight into how the things handle bad weather. |
Its natural for me to watch the numbers like a hawk.
Have 3 years of graphs on hand to draw from to upload with daily power consumption vs the average outside temperature to compare to this upcoming years numbers. The kill a watt meter numbers are priceless they show elapsed time vs power consumption. Have been and will be keeping the house at 21 to 22c so can enjoy some savings in the form of heat , enough of 18 and 19c. I have grown weary of it. Its been 20 days with the portable but the heating season does not really begin until November. So far the consumption about the same as its always been about $57 bucks in electricity a month with utilities about $33 of that is for heat The unit was cycling on and off every 10 minutes after the duct was added so I put it on a timer at 1hr off 1/2 hour on cycle for a 33% run time. Tonight will be a test its been good with that setting for the last 4 hours or so. In closing we have a few nights with 2 an 1*c night time temps coming up I will be sure to watch it Kwh consumption closely and will post its day time Kwh usage vs night time results / numbers. I will be sure to log them and post the numbers maybe with a few charts for accuracy . |
To start with here is next weeks weather
https://screenshots.firefoxuserconte...dbc5f03a86.png This is what the AC is dealing with atm This is the *houses* daily KWH vs outside average temp since the machine has been hooked up https://screenshots.firefoxuserconte...06c98a0e5b.png Thought its a good time to show the power consumption before the added duct and new on/off schedule change the numbers http://ecorenovator.org/forum/member...5-img-1336.jpg http://ecorenovator.org/forum/member...6-img-1334.jpg Elapsed time since the AC was hooked up followed by the KWH consumption , atm its 3 kwh off a 50% run time cycle over the last 20 days. |
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As long as you are only de-powering the stack effect you shouldn't see an increase in gas usage, even in below freezing temperatures. Think of it like this, when it is cold outside the stack effect drives a certain amount of ventilation in the home. Heated air inside the home rises creating a higher air pressure at the ceiling than at the floor. This is because we are adding energy to the air. This is also the reverse of natural air pressures. outside the air has a higher pressure at the ground than it does 20' up (generally anyway). This creates some fairly major pressure differentials that drives air flow through the building. We can use mechanical fans and change how the pressures are inside the house. By negatively pressurizing the house with mechanical ventilation we are in effect doing the same thing the stack effect does, only we are controlling where the air exits from. With your unit as long as the CFM is less than or equal to what the stack effect would be, then it actually acts like a HRV that is probably around 90+% efficient. *that has nothing to do with energy use only the amount of "available" energy the unit is able to harvest from the ventilation air. Of course to do that we need to be cognizant of how we are adding the heat back into the house and where we are pulling air from, it is possible that we could just end up pulling more air through the house and not doing anything about the stack effect. |
Hey Dend I was not thinking about the stack effect but can see how this plays a role. Mixing the air temperatures differences via a return duct or equivalent would help to elevate the pressure differences.
I gave up the hope of heating with the single hose set up , its negative pressure was MUCH stronger then I was lead to believe by the online quoted numbers. I was reading the portable ac would exhaust 1/3 its front sides output our the rear that was wrong it turned out it expels 240 CFM out both the vents. making for much too strong negative pressure to allow heat to warm the upstairs. I tried it out on two days it did nothing but super heat the downstairs room room to 35c The intake hoses in the photo are strung out the window the unit breaths 100% outside air now. It no longer creates negative pressure. Its basically acts as a non inverter mini split at this point with me controlling its on / off cycles via a timer. to be clear this unit uses two fans one for the front heat and one for the exhaust so the two air streams never meet. |
https://screenshots.firefoxuserconte...7a61d3c28c.png
Temp went down to and is currently at 1c with viability at 75 feet due to Fog. The house was at 17c this morning the ac air temp at the top of the stairs was 84*f I want to wake up to a warm house so this will not do The ac was moved to a 1hr on/off cycle yesterday this was not enough time for the unit to heat the house during the cold foggy night so i switched it to run solid for the next 4 hours to warm the house up. Im not liking the timer before the unit maintained the temperature and would run more or less according to conditions. I put it on the timer as it was short cycling with about 3 on/off cycles a hour after the vent/duct was was added. Before the duct it was running on a long 1 hour on/off cycle at top heat. To overcome this poor thermostat control using the timer will take it off the timer and let it run and short cycle as it wants too. Had good luck using its built in thermostat before the duct was added it maintained the upstairs temp very well. All in the ac did all right given the conditions and low run time hours last night , I hope it does better without the timer in the same conditions |
Short cycling these smaller units doesn't really hurt your energy efficiency. They don't take long at all to ramp up, and the jolt to get started doesn't consume a considerable amount of power. However, the unit I had ran both fans the moment the compressor started. In either mode, if the condenser side fan was delayed a few seconds, the unit would ramp up faster and consume a little less energy.
Unless the unit is overrated for the space, most heat pump systems don't deal with temperature setback very well. Completely opposite of gas heaters and furnaces. Then again, it's actually difficult to find a permanent gas furnace rated less than 50kbtu. I replaced my "right sized" gas furnace in the trailer (14x70 champion steel box) with one from a double wide because it cost so much to run in frigid weather. The overrated furnace paid for itself the first winter. |
The short cycling has been warm cycles each cycle gets that pre warmed compressor and condenser heat.
What bothers me is those last 4 or 5 degrees come on slower closer to the end of a 10 / 15 minute on cycle. The short cycling issue has been fixed Cause was it uses a internal thermostat to control its on/off cycles that was being cooled too quickly by the exhaust fan http://ecorenovator.org/forum/member...xhaust-fan.jpg Was leaving the fan on 24-7 this caused the vent to draw cool air over the ac's thermostat cooling it. Before the ac duct the exhaust fan cycled the rooms air 24-7 without issue it helped to maintain a even temp between floors. The fix was this Inkird 308 temp controller which arrived yesterday http://ecorenovator.org/forum/member...-turns-off.jpg One plug controls a heating circuit the other cooling It allows me to turn off the fan after the AC shuts down , prevented it from cooling the AC's internal thermostat. The temp probe is placed in free air above the Fan box where some of the AC's warm air hits it. Can fine tune the start up delay by changing the relays cooling setting. At a 75*setting the fan stays off for 15 minutes , at a 77* setting turning the fan off quicker it leaves the AC thermostat warmer allowing it to cycle on a 40 to 60 minute cycle. It worked out well with last nights test the house was 19c this morning without short cycling. |
Been a looong time since a login/comment, I look time to time, got the heads up this am on email,,,this thread I have been through myself.
Single hose no good, too much infiltration. I even tried exhaust into the basement, maybe pick back up some heat in daytime. Nope. Just lowered the temp too much, pushed cold back to 1st floor. Returned them, 2 Haier 12k units, approx. $350ea. Got a new 14kbtu two-hose at HD bargain bin,,,$150-no hoses/manual/box. It is IN my basement, intake/exhaust out the window, heat ducted to the first floor thru a floor register. Some balance of pressure/flow between. Works good down to 25f, about 85-90f outlet temp. Backed with portable resistance oil heaters($10 at Walmart closeout). All on timers. This worked as primary heat 2010-2012, 66-68f, small heaters in bath, bedroom on a timer, down comforter/elec.blanky haha. Natural convection worked like a dream, 2nd floor. This setup ran 30-35kwh/day average, some 50kwh days. Under $100mo mostly. $.07kw/h. Northern Nevada, 6k feet asl, sub-zero ALOT. When propane was@ $3/gal, bill was $150-300mo, when the whole family was there. 30kbtu cast iron Vermont D/V stove. 900sf all 3 floors, base/1st/2nd. Basement stays 50-55f until it goes sub 0 for days. I did use the stove some, maybe 10 times/2-4hrs a winter. I was home maybe 10hrs 6days a week, back then I had a good pay/crappy lifestyle job. :lol: 2 homes/long distance marriage. By comparison (call it what you will), my home in Idaho ran $100/mo on nat. gas. But back then my wife was running the thermostat...so ?? Don't know if this helps, but you are not alone! I was trying to save $$, running 2 homes/heating. I rolled R19 on top of R30 in the attic, sealed stuff, a lot done. It was a heat gain/loss effort to learn/improve. Actual heat loss was 10-15k btu/h at night, average. What I found was a lot of mis-info, plenty of 'tribal knowledge' out there in the world of heating. I should post the solar air/air window heater@160f outlet, some other fun stuff Good Luck! |
Thanks AirSepTech and it is good to hear of your heating outcome using the dual hose.
25*f / -3.9 c is a low temp for these portables to be making heat , will be set if this model performs the same. These newer Ac's are designed different then the older portables A few years back First single hoses they used a fan that split its air between the front heat and rear exhaust port wasting cooled or warmed air via the exhaust duct. Next they made a dual hose with 3 fans it used one front fan one exhaust fan and one slightly smaller intake fan. this arrangement lowered air infiltration down but due to the differences in fan cfm it still made some negative pressure. this was done to insure a air exchange took place for good air quality I read. Then the dual hose came out with one front fan and one exhaust fan used to intake with as well as exhaust , eliminating any negative pressure. For the best Mod use a single hose ac with dual fans not a triple or single , with heater. These portable ac heaters seem to have a good defrost system |
Was a cold night last night its noon and still @ 1*c
Woke up to warm house at 19.8c the AC moved from a 50% run cycle up 20% to a 70% on duration. https://screenshots.firefoxuserconte...ea7a33ab3b.png This upcoming week is a chilly one Winter has arrived early by the looks of it. temp at the top of the stairs 30 feet down the duct has been in the high 80's low 90's. The downstairs room is at 61* this lowers the heat gain I see upstairs , if the downstairs was at 70 degrees I would be reading the upstairs vent in the high 90's. The temp at the AC"s vent taken with a IR gauge is 115*f at 240 CFM = 13,9996.8 BTU using the temp difference vs air flow method , with a 54* difference. The Air temp is 61 downstairs at the condensers intake and 115 at its outlet. The vent normally sits between 115 and 125*f with 135* found if I point the IR temp gauge deep into the vent. The 115* is taken from the top outside of the vent a few inches away from the opening. I used to take the Vents temp off the vent door but it was removed to fit the Duct. The door removed with a slight pry with a screw driver to dislodge one of the press fit hinges from there it slipped off without issue. |
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