Portable ac in winter weather
 

Woke up to a house temp of 17.3 degrees with the vent at the top of the stairs @ 84 degrees. Not bad for -4 temperatures.

https://screenshots.firefoxuserconte...f9572b3735.png

The AC consumed 6 extra kwh past 50% yesterday this moves its duty cycle to 83% power vs full power 100% of the time.


The unit at times has been running on reduced watts in this cold weather it was using 800 to 850w when I checked the power meter at 7 am. It normally runs on between 950 and 1050 watts until it nears and enters defrost mode where its watts drop to a low of 500w for a few minutes.

Its been doing quick defrosts as needed throughout the night and morning

To warm the house up quick this morning i turned on the baseboard heat in the living room for 60 minutes to bring the house temp up to 20c and turned it back off.

So I cheated but it only makes sense as Im trying to save energy and not be cold doing it.

had a technical issue uploading this pic

http://ecorenovator.org/forum/member...-f-outside.jpg

The temp was taken from the ACs outer vent area @ -4 outside temp with a room temp of 17c

It was a cold night again last night with a -5 temp at 10 pm

http://ecorenovator.org/forum/member...emperature.png

Its currently -2c at 8 am with a 17c inside / house temperature

I turned the living room baseboard heat on again at 8 am this morning and will leave it on for an hour again to raise the house temp back up to a comfortable 20c

Yesterday morning after heating the house up to 20c the AC maintained the temp at 18.8c for hours eventually it climbed up to 20.5c and held until about 9 pm when it lowered to 19.5c at 1:00 am the temp was 18.4c

7 hours later it was 17c at 8am

With the cold weather the AC has been making at least 1/2 as much defrost water , its been running constant


Tomorrows weather prediction is said to be wet and mild with the following day forecast set at -5


Its usually not until the end of December that we see the cold of temperatures. The rest of the week forecast predicts wet and mild weather , its going back to normal.

The cold snap has finished and the heater actually worked right threw it.

The kill-a-watt meter now reads 763 on hours with 431 Kwh consumed
It consumed 50 kwh over a 50% run time using its 1000w power draw.
Is sitting at a 66% run time with a average power draw of 640 watts

Those numbers will climb as winter continues the percentage will rise
until ( I estimate ) bottoming out at about at 80 or 85% run time due to its lower power draw moments it has when it frost up and enters defrost mode.

After finding the house too cool in the morning added in a ceramic heater set on 500w draw mode , that draws 600 watts set on a hour on hour off cycle for 12 hour on every 24hrs
It worked out perfect for keeping the house at 20c

A few charts I downloaded the data from B.C Hydro our electricity supplier website

http://ecorenovator.org/forum/member...ion-data-4.png

Im the light blue bars the dark blue are neighbors , you can see the increase in power draw at the end of the chart

http://ecorenovator.org/forum/member...-cold-snap.png

http://ecorenovator.org/forum/member...ption-data.png

Its been smooth sailing since the last post with no issues whatsoever. I have not needed to adjust its thermostat the temp has been reliably steady at 20c with its current setting.

Having the ac downstairs is working out well the air circulates much like a proper duct system with the stairway acting as a large easy to flow through return duct.

A snap shot showing the temperature and heating trend for the last 30 days
https://screenshots.firefoxuserconte...5c1201d0ab.png

Success

First a Tip , If you try this yourself , pick a portable ac with heater as its defrost is tweaked to deal with frequent ice ups quickly and efficiently. Defrost last about 5 minutes and happens about every hour before Defrost heat output starts to reduce slowly.

The defrost has been working well , I have been checking on the condenser during bad weather and its been clear every time after a defrost.

Dec 2015 average temp 5.4*c =1600 KWh = $175
Dec 2016 average temp 2.3*c = 1900 KWh = $220
Dec 2017 average temp 3.2* = 1165 KWh = $125

https://screenshots.firefoxuserconte...35b99d668d.png


As it works out this Dec the heat pump reduced power consumption by 43% vs. 2016 and 27% less then Dec 2015 .

The heat pump fan and duct cost $420 - first month savings of $95 so about 1/4 of the way to pay back already :eek:

I am finding 12000 Btu's to about perfect for the house I have been using a 600w heater on colder days/ nights set on a hour on / off schedule to supplement the heating.

The ac has been running 24 hrs a day 24-7

It has consumed 1398 KWh over 2057 hrs. this equals a average draw of 690 watts

I am expected to save around $100 in January the way its going that will move me to about a 50% pay back in the first few months

At this rate it should be payed off this year.

Oh no, there's no way what you're talking about can save you money. It just has to be some confusion or placebo effect or sumthin...

NOT

Good for you, man! Your little project that shouldn't do what it does could very well pay for itself in only a single heating season! I'm sure your tweaking the performance early on are making a lot of difference. As long as it works for you, that's all that really matters.

It pulled it off in dual hose mode like a champ I have strong confidence in it now. This week has been warmer and have not been using the portable heater and still the house is 19.5* at 2:00 am.

Im astounded by its performance heating in -5* temperatures the gamble payed off ,, thanks to the dual hose mod :)

Hi! I have tried using a portable heat pump to heat up a 46 foot boat this winter, but my experiance hasn't been as good as yours. Here it uses way too much air, even in 2-hose mode. I guess that has a lot to do with the amount of air being much smaller in a boat. Even in 2-hose mode it blows out the double of what it sucks in, so my floors are getting icecold. I even opened it and tried to force it to suck all air from outside, by stuffing rubber foam here and there. But that only made it blow much colder inside. I have given it up for now, but I have a dream of chopping it in two and make a micro-split. :)

Don't give up on it instead Mod it.

Single hose units work best for this Mod but its doable with a dual hose
The problem with dual hose units is they use 2 different CFM fans with the exhaust being larger as a result it draws air in from the cracks and cycles the indoor air with fresh. *I read* its done so the air stays fresh in the room ie: stale air out with some fresh air in to keep the house from breathing.
Personally i think the design is in place to cripple the portable market but read the design is there to ensure the houses will get adequate oxygen exchange.

First Mod I would do is add a 2nd intake port and add a six inch flex hose to the outside.
If that did not work I would make sure the exhaust vent system is sealed to the intake side so the airflow is in and out.
I imagine adding a 2nd 6 inch intake vent to the side of the unit would be enough of a mod to fix the issue.

Energy update

I switched from the equal payment plan ( yearly use split into a monthly bill ) to monthly billing as the yearly equal payments were more then this winters monthly electric bill. Was $120 a month x 12 now its less then $120 for the winter months only. Spring and summer bills are going to be light on the wallet. I will start to see the savings in the wallet in about 1 month :)


When I stopped the equal payment plan it switched me to the two month billing cycle. I pay half very month tp stay on top of it.

http://ecorenovator.org/forum/member...ption-data.png

The kill a watt meter died about two weeks ago the last reading I have off it puts its energy consumption average at 735 watts with defrost cycles. etc. causing reduced consumption. Normally it runs on about 900- 950 watts.

For a single hose ac add two hoses for a dual add a 2nd hose

http://ecorenovator.org/forum/member...nch-intake.jpg

Mount the unit so the exhaust is pointed straight out *do not use a reducer*


To move heat from the AC to the other end you will need fan and related duct.

Arrange it to suit your environment

That's a 200 cfm fan
http://ecorenovator.org/forum/member...xhaust-fan.jpg


Then sit back and enjoy heat :)

http://ecorenovator.org/forum/member...80-degrees.jpg

We need more information on what you have, what you are looking to make it do, and how the machine is set up and/or modified to achieve your goals. It's difficult to speculate on which way to go if we don't know where you are. As always, pictures help out immediately and immensely. If you don't have enough posts to upload pictures, just blog up some stuff in your introduction. If you don't have an introduction, post one.

The masses await your response.

Sorry guys, I didn't mean to hold back on information, I just tried not to ruin other peoples treads with too much other stuff than the tread is about. I just wanted to say that my experiance was not as good as his.

Here is a link to a manual for the machine I have. Mine is called Matsui MPA12KH, and is 12000 BTU (10400 BTU on heating), but otherwise its the exact same machine in that manual.

https://www.homedepot.com/catalog/pd...bbf71f0487.pdf

The manual says that it discharges 360 m3 pr hour, and takes in 180 m3 pr hour in 2 hose mode. The 180 m3 not coming from the intake hose, is taken from the filter, the manual says. (I understand this as that the last 180 m3 comes from the top fan.) It also says that the intake hose should not be used and the intake should be blocked if the temperature outside is lower than inside temp. I tried this first, but this way it stole way to much air from the boat and the floors got really ice cold. I have the engine room just below my living room and there are 6 intakes there to handle the air the engines need. I guess thats why my floors get so cold. This way the heater worked good (gave about 45 c air) but as I said the ice cold floors ruined it.

Then I tried to use the intake hose anyway, even if the outside temperature was -5 c. That gave me about 40 c hot air, but the machine still stole too much air and the floors were still getting too cold.

Then I opened the unit and did my best to seal around the lower HX (evaporator in heat mode) to make it not take any air from the filter, but take all the air from the intake hose. This was sort of successfull, so now the machine did no longer steal too much air from the boat, but the result was that now it only managed to heat the inside air to 32 c witch is not enough to keep my boat warm. In fact this way it did not work any better than a 1000w fan heater does, maby even worse.

Both my hoses are 5". I measure temperatures by putting the outside sensor of a temp meter inside the hot air discharge. The machine plate says max power usage is around 1100 watts, but it never used more than 8-900 watts while I was testing.

I didn't take photos while doing my work, but I attached a photo now that shows how I tried to seal of the lower HX.

As I said in my first post in this tread, I am now planning to try to split the unit in 2 parts, and thereby convert it into a "micro-split" unit.

Thanks for the advise to make another intake hose, maby I would have tried this if it wasn't too late, becausae now I have allready emptied the unit of cooling media to be able to start the splitting job.

Cool your going to make a mini split from it. It will be nice having the compressor outdoors rather then in the boat. If I was to make a mini split from this portable I would mount the indoor unit in a vented box and duct the heat or cold to where its required

Ok, so if you are going to split the unit, make sure you put the larger heat exchanger outside. If it were mine, I might even find a larger size heat exchanger to do the job. A larger outdoor heat exchanger will raise your efficiency as long as it has enough airflow. Either way, I would definitely fit a txv to the outdoor heat exchanger if I changed it. I don't know if I would locate it in the engine room, since it would work against the indoor space through the floor.

Leave the cap tube on the indoor hx and decide where to locate the compressor. It all matters what mode the unit will be operating in more. If you need more heating duty than cooling, locate the compressor inside the envelope and the compressor waste heat will help warm the space. If you will be using it more for cooling, locate the compressor outdoors and the waste heat will dissipate into the outdoor air.

If you want help and/or guidance to pull off a successful custom design, start a thread about your adventures so far. This forum is full of people who can provide you with the information you need, when you need it. There is a lot to know and many decisions to consider before you get too far along in your project.

Portable ac outsidethe house vented in
 

Av easy mod

Keep a single hose or dual ac (with heater ) out on the porch and vent it in :)
Who knows might work for years if its kept dry. Be good to try with a cheap / free one ..

edit , more thought required ..
The pressure may be too much for the fan ...

The heating season is over the numbers are in it appears the ac has payed for itself in these last 5 months of use. The duct and fan played a big part in the savings spreading the AC's heat to the house , highly recommend its use with a portable AC.

Its likely the key to the Ac's successful season.

Below the chart has last years consumption vs this years.

http://ecorenovator.org/forum/member...ption-data.png


The two tier billing made for some good savings

First tier = 22.2kwh per day $0.0858 cents Kwh (30 days 665 kwh)

Second tier = anything over 665 Kwh per month cost $0.1287 (50% more)

2017 monthly Kwh

Dec 1900
Jan 1840
Feb 1600
March 1570
April 900

Season total = 7810 kwh minus first tier 3330 kwh = 4480 kwh 2nd tier rate

1st tier 3330 x 0.0858 cents = $285
2nd tier 4480 x 0.1287 cents = $576

Total $861 (minus taxes & fees)

2018 kwh

Dec. 1165
Jan. 960
Feb. 900
March. 738
April. 534

Season total = 4297 Kwh minus 3330 kwh = 967 kwh for tier two pricing

3330 kwh = $285
967 x $0.1287 cents =$ 125 Total = $410

$860 minus $410 = $450 saved on heating

Portable AC was $350 Fan was $80 10 inch aluminum duct cost $20 forget what I payed for the 6 inch duct I had it already.

In closing , I will likely use the ac on the hottest days of summer which will add to the yearly total. I really enjoyed using the heat pump , this winter the house was kept warmer then I would of with the electric baseboard heat.

Will post back Dec 2019 with the full years consumption Data to complete the test run.

keep happy