Monday, August 31, 2009

Great savings with extra water heater insulation

We have under the kitchen bench a 120 liter / 2000W electric water heater from Several spots outside this was warm to the touch, as indicated on the picture. I called technical support at Oso and they could confirm that it was OK to add extra insulation anywhere, also including the plastic lid that cover the ectrical wiring inside. So I used some spare insulation material and wrapped some plastice aound it all, and taped it up. For the pipes I got special insulation to wrap around the pipes. I have previously measured the standby energi consumption to be 1,8kWh/day. With the added insulation it as dropped to 1,2kWh/day. (You can measure the standby losses by measuring the energy used for a weekend when you are not at home using hot water. Use a plug in meter and just read off how many kWh that has been used to keep the water hot when you where gone).

We have the heater set at 65 C. Our family of five use about 7-8kWh a day for heating water.

I noticed how the power cord to the heater got warm when it was on. I cut off 1,2m of it for an additonal saving og about 4W ( 2,4m wire, 1mm2 copper, and about 8A) when in use :-)

Summary in Norwegian: Kjenn på utsiden av din varmtvannstank. Er den varm kan du med enkle midler spare mye energi. Bruk det du måtte ha av isolasjonsmateriale (Glava e.l.) og pakke det inn i plast til slutt. Alle varmtvannsrør bør også isoleres. Besparelsen hos oss var 0,6kWh/dag. Du kan også spare noe ved å forkorte tilførsledningen til et minimum.

Sunday, August 30, 2009

Cleaning and checking the heat pump

We got an offer from Lier Everk to get a service agreement for our Panasonic CS-CE7GK air-to-air heat pump. For NOK 1200,- (about $200) they would come and clean our heat pump every 2nd year. I did some research and it looks like you easy can do this yourself.

The first part is to clean the coils of the unit. Turn off the power of the unit. Remove the filter. Vacuum any dust that can be seen. Use luke varm water and dishwasher liquid (Zalo) and just spray your indoor coils. Use a towel to collect excess water dripping from the unit. The outdoor unit is cleaned the same way. Spray on. Wait for a while for the dish washer liquid to disolve dirt. Then use a garden hose with low pressure and apply water in the opposit direction of the normal airflow. Be careful not to bend any coil fins. Let the unit sit for some hours to dry before turning on power.

The second part is to check that it still delivers the heat (or cold) that it should. According to the Pabasonic service manual the difference should be at least 14 C in heat mode and at least 8 C in cooling mode. I checked ours by setting the temp to 27 C. Inlet temp showed 23C and outlet 42C. A difference of 19C (The unit using 484W). Then for fun I set the additional "Powerful" mode. Inlet temp is then 23 C and out take 48 C. (The unit using 985W). A differance of 25 C. Outdoor temperature was 13 C. If the temperature difference is less than 14C you should check that all coils are clean. If cleaning does not help, it is time to call for service.

Summary in Norwegian:

Du kan enkelt rengjøre din varmepumpe selv. Vask ved å spraye på med lunkent Zalo-vann. Utdelen kan i tillegg spyles med hageslange med lavt trykk, aluminiums finnene må ikke bøyes. Det skal være en temperatur forskjell på minst 14 grader mellom luft som går inn i inndelen og luft som kommer ut av den ved normal drift.

Insulate your unused chimney

Some years ago we had a fireplace, but we never used it that often, and there was always a cold draft from it when it was not in use. So we sold the fireplace (and got space for a home movie theater instead..) and sealed off the chimney. Much of the draft was gone, but last winter I noticed that the chimney was still very cold when touching it. Both on the ground floor, but even more on the first floor. No wonder when all that cold outside air fills the entire chimney.
So in preperation for this winter I made a simple unused chimney insulation. I used a total of seven plastic bags, each filled with some insulation material. After tieing the top of each plasticbag, I connected them all together with a string. Using a long stick a pushed the first one about 4 m ( 12 ft) down the chimney.

Then I pushed the next one a little bit shorter, and the next even shorter, and so on until the last one finshed it off right at the top of the chimney. This should defenitely slow down any cold air trying to go down the chimney this winter. Should we decide to get a fireplace in the future I can easy pull all the insulation bags out of the chimney using the string that interconnect them all.

Summary in Norwegian: En ubrukt pipe er en kald pipe. Du kan isolere pipa ved å trykke plastposer med isolasjon ned i pipa. Hvis du forbinder dem alle med et tau, så går det greit å få dem opp igjen hvis du skal bruke pipa igjen.