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#381 |
Helper EcoRenovator
Join Date: Oct 2009
Location: Portland, OR
Posts: 56
Thanks: 13
Thanked 1 Time in 1 Post
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![]() Thanks Rich! Yeah I don't think I'm getting too crazy with the oversize of the system. We have 4 rooms connected together in a row. I think that if I get a bigger size unit I'll get a little more heat further down the hall.
I must say you all have been amazing with your responses here. I don't think I would have the guts to try this without your encouragement. I placed the order this morning ![]() I'll check into the permit thing. That does seem awful suspicious. Thanks, Chris |
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#382 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
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![]() Okay Chris! Good luck with your install. When I placed my order,
I was a bit nervous about being able get it done. I knew DIY was a gamble, but I wasn't spending beyond my means. I also knew it was something that would be helpful to our comfort and our budget, if I could get it working. I had read where other guys had done it, so why not? ![]() IMHO, investing in a modern mini-split is going to give you a better return than buying a 3D HDTV or 2 or 3 ounces of gold. I've starting playing with the idea of running the Sanyo off-the-grid, using solar during sunny day time hours. I know it would take years to break-even on the hardware, but I just like the idea of being able to heat or cool my home for "free" or when the grid fails. I have already accumulated most of the parts I'll need. Just have to find out if my Sanyo will work with MSW or does it need true sine waves.. ![]() Life is short, so make mine an Adventure. ![]() Cheers, Rich |
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#383 | |
Supreme EcoRenovator
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
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![]() Quote:
However, from all the way over here in Portland, Oregon, I did some Googling around and came up with an outside design temperature of 14 degrees F for Philadelphia. There's probably something in Philadelphia like an office of the State Department of Energy, or something similar. They are very likely to have statistical information on winter time temperatures where you live. They can probably tell you exactly what the proper outside winter design temperature is for your location. Fifteen minutes and a few phone calls and you will know for sure. ...but it's likely to be pretty close to 14 degrees F. I found another bell curve picture: ...ignore the number on the bottom of the diagram, they are standard deviation numbers, nothing to do with what we are talking about. So you said that the average temperature where you live is 25 F. On the bell curve picture, that would fall right in the middle of the bell curve, right where the black line is. If you sized your heating system for that temperature, your heating system would be able to provide heat for half of the days during the winter. The other half of the days, your heating system would be insufficient, so you'd be cold. The design temp point is to be somewhere close to the red line I have drawn in the chart (imagine that the red line is around 16 degrees F). That way, your heating system will produced heat sufficient to keep your house warm on all but a small number of winter days. On those few days, your heat pump will not be able to provide heat as fast as your house is losing it. With a heat pump, you want it sized a little smaller than your maximum demand, and on those really cold days ("blue northers" we call them) you would utilize a secondary heat source. Xringer uses his oil furnace. I close off parts of my house I don't absolutely need to heat, and if it gets really bad, I use an electric heater. Some heat pumps have resistance heating wires built in. To my knowledge, no mini-splits have built in resistance heating wires... you'll have to provide the axillary heating with a wood stove, gas heater, electric heater, etc. That should pretty much do it... -AC_Hacker
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The Following User Says Thank You to AC_Hacker For This Useful Post: | cholcombe (04-04-11) |
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#384 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
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![]() "Some heat pumps have resistance heating wires built in. To my knowledge, no mini-splits have built in resistance heating wires..."
I found out just a while ago.. There are a few of them on the market now.. I guess that's not a bad thing.. ![]() |
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#385 |
Helper EcoRenovator
Join Date: Oct 2009
Location: Portland, OR
Posts: 56
Thanks: 13
Thanked 1 Time in 1 Post
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![]() I've really learned a lot reading this thread. Oh I had another question. With the condensation line how does it work when you have the lines for the indoor air handling unit drop down from the ceiling? I didn't think it would drain properly.
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#386 | |
Supreme EcoRenovator
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 724 Times in 534 Posts
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![]() Quote:
-AC_Hacker
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The Following User Says Thank You to AC_Hacker For This Useful Post: | cholcombe (04-05-11) |
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#387 |
Supreme EcoRenovator
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 724 Times in 534 Posts
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![]() Another consideration when sizing your ASHP, when the outside temperature goes down, the amount of heat output that an ASHP can deliver also, unfortunately, goes down. This is different from a fossil fueled heat source or a ground source heat pump.
I generated a chart, based on some data that Xringer dug up, that should suggest this situation: ...so when the weather gets colder (and you need more heat), the ASHP has less heat to give. So if your design temperature was for instance 16 degrees F, and you did a heat loss calculation and therefore knew you needed say, 12000 BTU to do the job, you wouldn't go for a 12,000 BTU unit, you'd need to go for an 18,000 BTU unit, because that would be the closest to do the job at 16 degrees F. This would be adjusted for the reduction in efficiency as the outside temperature gets lower. Regards, -AC_Hacker
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I'm not an HVAC technician. In fact, I'm barely even a hacker... Last edited by AC_Hacker; 04-04-11 at 06:16 PM.. |
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#388 | |
Apprentice EcoRenovator
Join Date: Dec 2010
Location: Arizona
Posts: 145
Thanks: 0
Thanked 2 Times in 2 Posts
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![]() Quote:
I have the opposite problem. I need to combat the heat. In image below the green square is the proposed cooling area. I'm thinking 80 in the summer and 70 in the winter. The summers are my main problem. Shop can reach 130 degrees inside and 115 outside. All walls, garage doors and ceilings are insulated. Looking at Sanyo 24,200 BTU Wall Mount Heat Pump Air Conditioner Kit. Is this doable or over kill? Vern ![]()
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#389 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
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![]() Vern, can you use a Swamp Cooler? Maybe one you can drag into the area where you are working?
PAC2KCYC01 Port A Cool Commercial Swamp Cooler With Centrifugal Air Delivery System - ![]() |
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#390 |
Supreme EcoRenovator
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 724 Times in 534 Posts
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![]() It all starts with a heat loss analysis, only in your case, a heat gain analysis... Without that, it's just guesswork. But the basics are the same:
-AC_Hacker
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Tags |
air conditioner, diy, heat pump |
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