EcoRenovator  

Go Back   EcoRenovator > Improvements > Geothermal & Heat Pumps
Advanced Search
 


Blog Register 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 05-09-13, 03:39 PM   #1
Nonhog
Knows enough to be danger
 
Nonhog's Avatar
 
Join Date: Dec 2011
Location: Washington state
Posts: 24
Thanks: 5
Thanked 1 Time in 1 Post
Default Heat pump thoughts

3 bids for heat pumps. 3 different suggestions.

A little background. 1700 sq. ft. home with a 15x15 unconditioned atrium in the center. The entire roof is glass and the back wall is near 18' tall.
(lots of volume)

Currently we have propane furnace and water heater.

Our goals are lower utility costs. Stop burning wood. (I know 2 directions right there)
Make the atrium warmer in winter and cooler in summer.(not perfect-just better)
Probably by adding registers to the atrium walls.

Back to the bids.
1st company suggests adding a ductless wall mount in the atrium. and opening the windows to the main room(s) allowing heat to filter.
(I'm no expert but that co. will not get the job)

2nd company, suggest adding 3 ton heat pump to current Propane furnace.
Sounds logical to me.

3rd company says get rid of propane furnace as well as our instant hot water heater (also propane)and add there 4 ton system.
He didn't suggest a new water heater so I can only assume he means get an electric instant water heater which is off topic. Deal with that later.

I always thought electric heat pumps don't perform well in very cold weather.
Seattle area gets a few days a year below 30.
My co-worker has a electric heat pump and said its fine in the winter.

Our propane furnace is only a few years old. Should I retain it as a hybrid
system for our home or move it to my shop?
Not giving it to anyone to recycle.(as suggested)

Thoughts?
More info needed? If so what?
Thanks!


Last edited by Nonhog; 05-09-13 at 03:42 PM..
Nonhog is offline   Reply With Quote
Old 05-09-13, 05:28 PM   #2
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,002
Thanks: 303
Thanked 712 Times in 532 Posts
Default

Quote:
Originally Posted by Nonhog View Post
Back to the bids.
1st company suggests adding a ductless wall mount in the atrium. and opening the windows to the main room(s) allowing heat to filter.
(I'm no expert but that co. will not get the job)

2nd company, suggest adding 3 ton heat pump to current Propane furnace.
Sounds logical to me.

3rd company says get rid of propane furnace as well as our instant hot water heater (also propane)and add there 4 ton system.
He didn't suggest a new water heater so I can only assume he means get an electric instant water heater which is off topic. Deal with that later.
Your best bet would be to retain your propane heat as backup and get a heat pump that was just a bit too small.

The rule of thumb (thumb rhymes with dumb) is 1 Ton per 1000 square feet.

The rule of thumb knows nothing about your insulation, and neither do we.

By the rule of thumb, a 1.5 Ton would do it.

But if you had great insulation. a tight house and good windows, 1 Ton or less would be fine.

If your insulation was awful, 3 Tons or more might be required.

I'm beginning that professionals will oversize so they don't have to do call backs. It might also be that they don't actually know how to do an accurate heat load analysis, therefore they can't 'cut it close' because they don't really know what the heat load is. At any rate, when they oversize, the consumer doesn't get the maximum performance for the money they spend on monthly utilities.

Aslo, when it comes to heating their house, most homeowners think first about how to heat, with insulation as an afterthought.

Too bad, it should be the other way around... you should go to every length to keep the heat in the house.

With heat pumps, bigger is not better. Just a bit too small is best, and use some form of backup (wood, propane, electric) to fill in.

You have all summer... insulate your house like it was going out of style.

-AC
__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...

Last edited by AC_Hacker; 05-09-13 at 06:55 PM..
AC_Hacker is offline   Reply With Quote
Old 05-09-13, 07:38 PM   #3
jlaw
Learning to save
 
Join Date: Dec 2012
Location: Eastern North Carolina
Posts: 19
Thanks: 1
Thanked 3 Times in 3 Posts
Default

I am living in a 1650 sq' ranch home. I have a 3 ton 15 seer heat pump witha propane furnace as back up. I live in eastern NC. Winter temps average probably about 30f. Sometimes it gets to 20f at night but almost always gets to 40f in the day time. I assume from your statements that you have something similar. I have 9 to 10" insulation in attic most of the house has 3.5 in walls, vinyl replacement windows, insulated entance doors and a double french door . House faces south so good sun exposure in the winter. It also has a crawl space and I insulated the floor beneath the house to 6.25".

Our electric rate is 7.5 cents per KWH and my all electric house has had a high electric bill of $190.00. I forgot to mention I use a Honeywell IAQ thermostat with an outdoor temp sensor to control the system. I rarely have to invoke backup heat. I have been using the same 200 gallon propane tank for 3 years. I also have a 4" high efficiency air filter.

If you get a heat pump, which I would recommend, get the Honeywell stat as well. It is very flexible and capable and worth the money. It controls every device that can be connected to the unit.
Thermostats | Programmable Thermostats | Digital Thermostat | Thermostat | Honeywell Thermostats
VisionPRO IAQ 7-Day Programmable Comfort System

Controls temperature and indoor air quality products from one control
Easy-to-follow menu driven programming
Smart change/check reminders on air filters, UV bulbs and humidifier pads

Make sure your contractor shows you his sizing method and explains how he came up with his figures. Make sure he will be sealing the duct work, you can lose 30 or more heat and cooling through duct leaks. Make sure they are quoting insulated duct work. Many contractors I contacted wanted to argue about how I wanted it done because it was more cost effective for them to do it their way.

Last edited by jlaw; 05-09-13 at 07:42 PM..
jlaw is offline   Reply With Quote
Old 05-10-13, 01:47 AM   #4
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,002
Thanks: 303
Thanked 712 Times in 532 Posts
Default

Quote:
Originally Posted by jlaw View Post
...I have a 3 ton 15 seer heat pump...
Do you know what the HSPF rating is on your heat pump?

The SEER rating better describes the cooling efficiency, while the HSPF better describes the Heating Seasonal Performance Factor.

Sometimes units with the same SEER ratings may have significantly different HSPF ratings.

-AC
__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote
Old 05-10-13, 05:00 AM   #5
jlaw
Learning to save
 
Join Date: Dec 2012
Location: Eastern North Carolina
Posts: 19
Thanks: 1
Thanked 3 Times in 3 Posts
Default

AC the information you request--9.0 HSPF.
jlaw is offline   Reply With Quote
Old 05-10-13, 05:28 PM   #6
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,002
Thanks: 303
Thanked 712 Times in 532 Posts
Default

Quote:
Originally Posted by jlaw View Post
AC the information you request--9.0 HSPF.
jlaw,

Thanks.

The HSPF is a performance rating that is based on how efficiently your unit will perform over the course of an 'average' winter. I think that there is some statistical determination of an average winter.

The number is the COP (AKA: Coefficient Of Performance) times the watt-to-BTU conversion factor which is 3.412.

So if you wanted to know the COP, you divide the HSPF by 3.412 and you get COP.

COP = HSPF / 3.412 = 9 / 3.412 = 2.64

Personally, I'm more comfortable thinking in terms of COP because it is unitless, and applies equally to the metric system and to our system in the US, so you can compare over a wider range.

I believe that you're in more of a mixed climate and would require both heating & cooling in approximately equal quantities.

where I live I only need cooling for about two weeks of the year, so my focus is almost exclusively on heating, so the HSPF is the most important for me.

When I bought my mini-split, I shopped for SEER because I didn't know that HSPF would be so important in my case. My unit, which I'm pleased with, has an HSPF rating of 7.7, so my COP is 2.25. Not as good as your and not so good in light of the impact that those numbers have had on my electrical bill. But it was a big improvement over what I had before.

For comparison purposes, the Fujitsu 12RLS2 is a 12,000 BTU (1-Ton) mini-split that has a SEER rating of 25 and a HSPF rating of 12 which would mean a COP of 3.52, which is pretty outstanding.

Let's hear it for improvements!

-AC
__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote
Old 05-10-13, 07:06 PM   #7
jlaw
Learning to save
 
Join Date: Dec 2012
Location: Eastern North Carolina
Posts: 19
Thanks: 1
Thanked 3 Times in 3 Posts
Default

AC
A while back I posted that I was interested in adding a water heat exchanger to my unit as I have a creek 100' away that never freezes. I had considered running tubing beneath the creek bed which is all sand and circulating glycol to increase the efficiency even more. I have been kicking this idea around now for about 6 months. Not sure that the cost of the equipment, heat exchanger, pump and controls and additional power to run pump would be offset with power savings. The heat exchanger for my size would be around 300.00 and the pump about 100.00 plus tubing, digging and other work.

In any case this is what I want to do. Not sure how I will mount and place the heat exchanger and pump without it looking ugly and cobbled.
jlaw is offline   Reply With Quote
Old 05-11-13, 12:45 AM   #8
jeff5may
Supreme EcoRenovator
 
Join Date: Jan 2010
Location: elizabethtown, ky, USA
Posts: 2,384
Thanks: 405
Thanked 604 Times in 506 Posts
Send a message via Yahoo to jeff5may
Default

Nonhog,

How much of the work are you planning on doing yourself? Are you looking for a quick turnkey solution, or are you willing to invest some sweat equity to save a considerable amount of cash?

It sounds as if you want to keep your existing ductwork and at least some of your existing equipment. Although it may be less expensive up front to just throw something in, you really want to get what you already have evaluated by an expert or at least do a decent energy audit/heat load analysis of your home before improving upon it. Most utility companies will do this sort of thing for next to nothing to point you in the right direction. You may find that your home leaks air or heat somewhere badly, and fixing the energy drain may change the economics of what you already have for the better.
jeff5may is offline   Reply With Quote
The Following User Says Thank You to jeff5may For This Useful Post:
AC_Hacker (05-12-13)
Old 05-12-13, 02:01 PM   #9
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,002
Thanks: 303
Thanked 712 Times in 532 Posts
Default

Quote:
Originally Posted by jlaw View Post
AC
A while back I posted that I was interested in adding a water heat exchanger to my unit as I have a creek 100' away that never freezes. I had considered running tubing beneath the creek bed which is all sand and circulating glycol to increase the efficiency even more. I have been kicking this idea around now for about 6 months. Not sure that the cost of the equipment, heat exchanger, pump and controls and additional power to run pump would be offset with power savings. The heat exchanger for my size would be around 300.00 and the pump about 100.00 plus tubing, digging and other work.

In any case this is what I want to do. Not sure how I will mount and place the heat exchanger and pump without it looking ugly and cobbled.
It would be very helpful if you gave us some more info on the building you want to heat, like how much heat is it going to need?

How did you determine the HX you require? How did you determine the pump you need?

The more information & photos you can share, the better the quality of the advice that will come your way.

Also, keep in mind that the more you are able to take measures to prevent heat loss, like sealing the house really well, and insulating beyond what is 'reasonable', the less you'll need to invest in the components to build your water source heat pump... and the less you'll need to spend every month to run it.

Best,

-AC
__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote
Old 05-14-13, 10:18 AM   #10
mejunkhound
Apprentice EcoRenovator
 
Join Date: Apr 2011
Location: PNW
Posts: 196
Thanks: 0
Thanked 47 Times in 31 Posts
Default

Nonhog:

#2 is the only one I'd consider (of the 3 you mention) if you are not going to do most of the work yourself. I added a 3T to son's hose and kept his nat gas furnace in place (near you, Kent, WA, so climate the same, his is 5000 sq ft house, the 3T work fine all year)

#1 is stupid, #3 is about getting you to spend the most possible.


How about #4, something you can DIY with minimal effort:

Buy 2 ea 1T or 1.5T inverter driven mini-splits online (19+ seer, about $1100 each including shippipng, saves you $200 sales tax right off) Install these at opposite ends of the house. Recently installed one in son's 800 sq ft office, very quiet, cannot even hear the outside unit running 20 feet away.

As for DIY, buy a good vacuum pump off ebay or similar (about $150 for a good one for your purpose) and a micron gauge - another $80 or so. The mini-splits have pre-formed flare fittings.
Install all the mechanical, torque the fittings to spec using oil on all surfaces (POE oil best, get some on line also, you only need a few ounces at most).
Pull a <500 micron vacuum for a few hours and verify no leaks. Open the outdoor unit valves and you are good to go!

If you decide to DIY the mini-splits, plenty of folks here can guide you thru details of the steps above.

Not an ad (I have no interest in the brand), but the last mini-split I bought on-line was a Klimaire for son's office - I figured I was taking a big chance on getting a piece of chinese junk for the low price I paid, but was VERY surprised at the quality and it has worked well for the 6 mo it has been installed. Was actually amazed at how quiet, esp. for someone used to the 80 dB monsters of yesteryear.

PS: leave your propane in place as a backup. ?? are you an seattle city light power or PSE? Probably PSE and off the nat gas grid if you are on propane now.


Last edited by mejunkhound; 05-14-13 at 10:22 AM.. Reason: added PS
mejunkhound is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 02:04 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design