Heat Pump WH to dehumidify + existing indirect ??

Lee_8

I live in Sothern NH and have a dampness / midew issue in the full concrete basement of our 45 year old home.  It wasn't an issue until we replaced gas atmospheric boiler and traditional HW heater a few years ago.  Apparently  their, pilots and flue were providing adeqaute ventilation even in the summer. 

We run a dehumidifier and fans most of the year which is likely eating up much of the savings from the direct vent boiler.  Ventilation and air to air heat exchanger don't solve the problem since they would draw hot moist air in to cool space in the summer.  

At a recent home show someone suggested using a heat pump HW heater in the basement, it would dehumidify and use the heat it produces to heat water.  Can this be used with our 40 Gallon indirect in a code compliant manner?  Could we use it as a pre-heated source to the indirect?  If yes what is the advised preheat temp to address legionella in a 2 person household, 145 F?    

pipeking

soo what do u have

an gas water heater or a boiler with an indirect? i am not quite getting what u have or r trying to accomplish, other than u have a moisture problem. yes, a heat pump water heater will dehumidify, and has tax rebate!

kcopp

Heat pump ...

water heaters are not all they are cracked up to be... especially in NH.(I'm in Dover) They are pretty noisy, will make the room they are in, cold and the electric rates are much higher as a general rule here. PSNH does not have a rebate for water heating...

 Why is you basement wet? Do you need to regrade outside and get the runoff away from your foundation? would a sump pump help? Would a more efficient dehumidifier help?

Lee_8

answers

sorry for double post..

Sooo.. We have a gas boiler for hydronic heat and Superstor HW.  Replaced oversized and old atmosherc boiler and free standing HWH.

HP ... Liquid water isn't an issue nor is grading.  I suspect that the poured concrete foundation has little or poor sealing and water vapor is getting through walls and floor.  Perimiter excavation and sealing is likely expensive.    I don't think the "Wave Ventilation is the answer , it is essentially a fan and humidistat.: http://www.wavehomesolutions.com  and cost about as much as heat pump water heater. 

Re: noise and cost we run a dehumidifier built to run at basement temps, in summer it is essentially non stop. I figure if I am paying P$NH then the heat pump by virtue of the HW generation would provide dehumidification and as a preheater reduce, slightly , my gas consumption.

A heating pro said that air to air isn't the answer because I would be bringing in moist warm air in the summer .

Any suggestions???



 

JeffM

electric supply

In southern NH, have you at least switched your electric supply company to someone cheaper than PSNH? I save about $10/month on my Manchester electric bill since the switching last year (and use electric just for lights, no heat or hot water). Not a lot, but it helps. PSNH supply rates are high because they own some power plants that are expensive to run, and switching to alternate suppliers with other types of plants nets a decent savings. We have 2 or 3 choices in NH now.

kcopp

Can you paint....

the walls w/ UGL drylock? How dry are you making is in the basement? Do not open the windows in the summer.... the humid air from outside will certainly condense on the cold concrete.

jumper

summer & winter

Dehumidifiers are more efficient than they used to be. I'd stick with dehumidifier. Buy an efficient small one.

kcopp

Another question...

hopefully not a stupid one....where are you dumping the water or where does it dump to?

pipeking

WHAT U NEED TO DO

is take all the info from the dehumidafier,hybrid wh, boiler, electric bill, gas bill, and do some calculations. weigh all the pros and cons.