Help me get the most out of heatpump water heater

Brandon727 · 01-30-15, 08:33 AM

long time lurker first time poster. i will be adding a heatpump water heater within the next few months. i'm looking to maximize the energy savings so i'm looking for tips on location, if i need to add intake or exhaust fans, heattraps, etc,

I just bought my house last year, first thing i did was install led bulbs(7w and 9w) in every fixture and rewired 2 florescent tubes to led(13w and 18w), i then installed a 1.5gpm and 1.75gpm shower head in out two showers, 1.0gpm aerators in the 2 bathroom vanitys and a 1.8gpm(vs the 2.2gpm) kitchen faucet. replaced 2 old crank out windows that wouldn't shut(1" gap). plugged various holes in the roof, and added a programmable t-stat, the house came with a water heater timer I use. My plans this year are to replace the remaining 5 crank out windows, add insulation, and switch to a heat pump hot water heater.

Home specs
Avg useage over the first 10months 827kwh(27khw daily)
1250sq ft a/c space.
Location Coast of central Florida so very humid and hot most of the year.
2 people with plans to add a third(kid). so usage will only go up.

Living in coastal Florida i think i would benefit greatly by installing a hybrid water heater as i should be able to run it 300+days a year in heatpump only mode.

I will be installing it in my garage 11"x24"x8"(2100cuft) but the attic is open into the garage so i have plenty of space to draw from.

i have freedom to mount it where i need to so what is a better choice close to the interior wall or the exterior wall, would I benefit from any intake or exhaust fans/vents and would setting up heat traps be helpful, any other tips are appreciated.

hamsterpower · 01-30-15, 09:23 AM

Considering your location, I would try to find a spot inside the conditioned space to install your water heater. Reason being, to get the benifits of the cooling/dehumidifying inside the house.

Brandon727 · 01-30-15, 11:08 AM

Quote:

Originally Posted by hamsterpower

Considering your location, I would try to find a spot inside the conditioned space to install your water heater. Reason being, to get the benifits of the cooling/dehumidifying inside the house.

the current water heater is in the garage so keeping it in there is easiest(cheapest), and the only closet i could put it in inside is across the house, I have a very small attic not crawl friendly, so reruning piping would be a bear and costly that is a more last resort. I would be willing to run a duct from the house to the water heater to get the cooling/dehumidifying effect, any write-ups on here i can look at?

Geo NR Gee · 01-30-15, 11:49 AM

Where is the current water heater in regards to the Cooling/Heating unit? In WA the practice for new construction is to have the hot water heater and heating/cooling units next to each other, so it would be easy to vent the conditioned air to the supply line during the cooling season.
If I remember right the last time I was in Florida, some are on the roof away from the hot water heater.........

Brandon727 · 01-30-15, 12:19 PM

Quote:

Originally Posted by Geo NR Gee

Where is the current water heater in regards to the Cooling/Heating unit? In WA the practice for new construction is to have the hot water heater and heating/cooling units next to each other, so it would be easy to vent the conditioned air to the supply line during the cooling season.
If I remember right the last time I was in Florida, some are on the roof away from the hot water heater.........

in the crude picture attached the water heater is the red X, the Cooling/heating air handler is the Black X, to the left of the A/c is a door into the house so i can't install there but i can put it on the right side and run any vents.

hamsterpower · 02-01-15, 06:07 AM

Quote:

Originally Posted by Brandon727

the current water heater is in the garage so keeping it in there is easiest(cheapest), and the only closet i could put it in inside is across the house, I have a very small attic not crawl friendly, so reruning piping would be a bear and costly that is a more last resort. I would be willing to run a duct from the house to the water heater to get the cooling/dehumidifying effect, any write-ups on here i can look at?

It would be unwise and against code to duct garage air into the house. A HP water heater also can not be hidden in a closet as it needs lots of air movement to work correctly. If you are not willing to place the unit inside conditioned space (to help with cooling load) then you are likely better off with an on-demand water heater. The cheaper efficient option.

Geo NR Gee · 02-03-15, 12:52 AM

Could you have the heat pump water heater unit in the garage still and pull in air from the return and dump the conditioned air into the supply? There would be no garage air involved.

hamsterpower · 02-03-15, 05:50 AM

Quote:

Originally Posted by Geo NR Gee

Could you have the heat pump water heater unit in the garage still and pull in air from the return and dump the conditioned air into the supply? There would be no garage air involved.

I'm sure my GeoSpring is not air tight even with the add on duct kit. I doubt any commercially availible units are, but it could be possible with a DIY project.

Semipro · 01-30-15, 12:24 PM

You could mount it in the garage and vent the output to the house.
Of course, if you actually park vehicles there or store potentially dangerous chemicals you won't want to do this. Maybe you could duct air in directly to the unit through an outer wall and direct air out to the house.
Keep in mind you'll have condensation to deal with so you'll need a place to drain water.
If you go with a Geospring the other post here regarding the availability of a duct kit may interest you.

Brandon727 · 01-30-15, 12:30 PM

The geospring wasn't on my list as it was a 2.4ef and for the same price i could get the whirlpool that has a 2.75ef, but i was just looking and i see GE is rolling out there updated Geospring line that is ~3.1ef in the next few months so if it is within $100 of the whirlpool i will pick it up.

How much will the ducting help? yes i know it's a case by case basis but where is a avg price that makes it worth it, if the kit is $25 i will do it, but at 100-150 is it worth it long term?

01-30-15, 08:33 AM	#1
Brandon727 Lurking Renovator Join Date: Jan 2015 Location: Tampa Posts: 11 Thanks: 0 Thanked 1 Time in 1 Post	Help me get the most out of heatpump water heater long time lurker first time poster. i will be adding a heatpump water heater within the next few months. i'm looking to maximize the energy savings so i'm looking for tips on location, if i need to add intake or exhaust fans, heattraps, etc, I just bought my house last year, first thing i did was install led bulbs(7w and 9w) in every fixture and rewired 2 florescent tubes to led(13w and 18w), i then installed a 1.5gpm and 1.75gpm shower head in out two showers, 1.0gpm aerators in the 2 bathroom vanitys and a 1.8gpm(vs the 2.2gpm) kitchen faucet. replaced 2 old crank out windows that wouldn't shut(1" gap). plugged various holes in the roof, and added a programmable t-stat, the house came with a water heater timer I use. My plans this year are to replace the remaining 5 crank out windows, add insulation, and switch to a heat pump hot water heater. Home specs Avg useage over the first 10months 827kwh(27khw daily) 1250sq ft a/c space. Location Coast of central Florida so very humid and hot most of the year. 2 people with plans to add a third(kid). so usage will only go up. Living in coastal Florida i think i would benefit greatly by installing a hybrid water heater as i should be able to run it 300+days a year in heatpump only mode. I will be installing it in my garage 11"x24"x8"(2100cuft) but the attic is open into the garage so i have plenty of space to draw from. i have freedom to mount it where i need to so what is a better choice close to the interior wall or the exterior wall, would I benefit from any intake or exhaust fans/vents and would setting up heat traps be helpful, any other tips are appreciated.

01-30-15, 09:23 AM	#2
hamsterpower Apprentice EcoRenovator Join Date: Oct 2009 Posts: 142 Thanks: 0 Thanked 11 Times in 11 Posts	Considering your location, I would try to find a spot inside the conditioned space to install your water heater. Reason being, to get the benifits of the cooling/dehumidifying inside the house.

01-30-15, 11:49 AM	#4
Geo NR Gee Journeyman EcoRenovator Join Date: Jan 2011 Location: Seattle Posts: 326 Thanks: 109 Thanked 23 Times in 18 Posts	Where is the current water heater in regards to the Cooling/Heating unit? In WA the practice for new construction is to have the hot water heater and heating/cooling units next to each other, so it would be easy to vent the conditioned air to the supply line during the cooling season. If I remember right the last time I was in Florida, some are on the roof away from the hot water heater.........

02-03-15, 12:52 AM	#7
Geo NR Gee Journeyman EcoRenovator Join Date: Jan 2011 Location: Seattle Posts: 326 Thanks: 109 Thanked 23 Times in 18 Posts	Could you have the heat pump water heater unit in the garage still and pull in air from the return and dump the conditioned air into the supply? There would be no garage air involved.

01-30-15, 12:24 PM	#9
Semipro Andy Join Date: Jun 2014 Location: SW VA Posts: 45 Thanks: 6 Thanked 13 Times in 10 Posts	You could mount it in the garage and vent the output to the house. Of course, if you actually park vehicles there or store potentially dangerous chemicals you won't want to do this. Maybe you could duct air in directly to the unit through an outer wall and direct air out to the house. Keep in mind you'll have condensation to deal with so you'll need a place to drain water. If you go with a Geospring the other post here regarding the availability of a duct kit may interest you.

01-30-15, 12:30 PM	#10
Brandon727 Lurking Renovator Join Date: Jan 2015 Location: Tampa Posts: 11 Thanks: 0 Thanked 1 Time in 1 Post	The geospring wasn't on my list as it was a 2.4ef and for the same price i could get the whirlpool that has a 2.75ef, but i was just looking and i see GE is rolling out there updated Geospring line that is ~3.1ef in the next few months so if it is within $100 of the whirlpool i will pick it up. How much will the ducting help? yes i know it's a case by case basis but where is a avg price that makes it worth it, if the kit is $25 i will do it, but at 100-150 is it worth it long term?