Wednesday, December 17, 2008

Happy Holidays and blog address change

Due to some blog set up issues we have recently moved all the old blogs to this new address. Thats why you may noticed the dates have all changed. All new entries will appear at this new address.

Happy Holidays

Friday, December 12, 2008

Heat Pump - part two

Continue from last post...

Some manufacturers have recently marketed what they dubbed as "Hybrid System". Essentially it is a heat pump system that is matched up with a conventional gas furnace. It is designed to be installed with a special controller with an outdoor temperature sensor. As we mentioned last time heat pump loses its effectiveness when temperature drops below roughly 45F. A "Hybrid System" simply switches to gas whenever that occurs. Keeping the heat capacity when it is needed most. It is more expensive but probably the best solution from a comfort standpoint.

A lower cost solution for most heat pump installations is the use of electric strip heat as back up heat source. It does draw quite a bit of power to heat up the space and most are set up for 220V power supply. Those are the main reasons why heat pump is not as common in the Northern California. However when the system is matched up with a solar electric system then consumption is not an issue.

Is a Heat Pump system suitable for your home?

We receive inquiries for heat pump on a regular basis and I think it is a good idea to cover the topic. Heat pump is essentially an air conditioner that is capable of running in a reverse cycle. There are a few types of heat pump: Air source, ground source, and water source. Due to the need and high cost for trenching or access to large bodies of water for the latter types, air source heat pump is the only common type used in urban residential area such as the Bay Area. Instead of rejecting the heat outside like an AC does in the summer, it rejects the heat inside in the winter. It is an alternative to the conventional gas or LP heating furnace.

The benefit of a heat pump system is that it uses electricity for its heat generation which reduces it carbon footprint when compared with a gas furnace. It also allows heating for areas that do not have ready gas supplies. However, the downside is that heat pump tends to lose its effectiveness when outdoor temperature drops below 45F. And from a operating cost it is more expensive to operate a heat pump in the Bay Area climate unless you have access to low cost electricity. And recently that option comes from solar panels that some homeowners have started to install on their roof.

Next time we will cover hybrid system and supplemental heat.

Back from Summer

It has been a few months since the last post. Summer has always been our busiest time and this last one was no exception. I am embarrassed to say my blog hasn't been kept up as I would like. Fall should be a good time for me to start back up and write about some relevant topics on the home comfort system.

If you have any topics suggestion feel free to leave a comment or email to

Friday, December 5, 2008

Save Yourself a AC Service Call

We had a heat wave here in the Bay Area two weeks ago with temperature up in the 90's for 2-3 days. It is unusual for this early in the season and caught a lot of homeowners by surprise. A lot of them haven't run their system since last year and found that their AC may not be in proper working condition for various reasons. Our service department probably got over two hundred service calls in the 1-2 day period. Needless to say our service technicians were overwhelmed and had some crazy hours. But with that many calls there is no way we can take care of everyone. And so here are some simple things to check that just might get you going again...

- Check your circuit breakers and fuses. The breakers are in the electrical panel. Make sure they are not tripped. It is not uncommon that during the really hot days the system may overstressed and tripped. If the breakers are still in the on position check the fuses at the disconnect by the unit. Usually it is a solid fuse. If you have an electrical meter you can check to see if the fuse is still good. You can pick up spare ones from any home stores to replace them. Make sure you buy the ones with the same amperage ratings.

- Check your air filter and make sure it is relatively clean. A dirty filter can restrict air flow to a point that it ices up the AC coil and stops the system.

- Check your thermostat and make sure it is in "Cooling" mode and the fan is set to "Auto". Also make sure your set point is lower than the room temperature.

If you have checked all of the above and they all are ok. Then a professional need to be called.

The best way to avoid all those problem is to run test your system before the next heat wave. We offer AC tune up service that does just that and more. Call us at 408-894-9072 to set one up!!

What SEER do you need for your Air Conditioner?

It is unusual that we get up to over 90F in the San Jose Bay Area. But it looks like that will be the case this week according to the forecast and most interestingly it is only May. So this is perhaps another proof that global warming is real. If you are reading this you are probably in the market for a residential air conditioner. Similar to furnaces, there are a few factors besides brand you should consider when you pick out that perfect system for your home. They are efficiency, capacity, staging, and refrigerant. We will go over efficiency in this article.

Just like you measure automobile mileage by miles per gallon, you measure residential AC efficiency by SEER (Seasonal Energy Efficiency Ratios). In short, it measures how much cooling effect in Btu/h your cooling system provides per watt of electrical consumption. The higher this SEER ratio, the more efficient your system is. As of January 2006, the US minimum standard for residential AC equipment is 13 SEER. This is an increase from a minimum of 10 SEER prior to 2006. The difference of a 13 SEER unit and a 10 SEER unit as you may tell is a 30% improvement in efficiency.

Most manufacturers make equipment with efficiency ranging from 13 SEER to about 20 SEER. It is important to note that the more efficient the system is, the larger the outdoor condenser AND the indoor coil are. So part of the considerations is the space available at your furnace or air handler AND your backyard location where the outdoor unit goes. And when a contractor tells you they are installing a high efficiency system, make sure they are using a matching coil that provides the advertised efficiency. Otherwise, you may be paying for extras that you don’t benefit. For example if your furnace is in a tight closet 13 SEER may be all you can squeeze out because of the indoor coil size constraint. Have an HVAC professional evaluate your situation and ask for the official ARI test rating for the condenser coil combination if you are in doubt.

We will continue the topic next time on capacity.

AC Spring Tune Up

We had an early summer last week that sent our service technician scrambling. Temperature got up to the mid eighties in San Jose that had a lot of the home owners running their AC system first time for the season. Needless to say, some of them found that their old system is not working anymore. That’s where we come in. To avoid these surprises, you should have a regular check up on your comfort system just like you would do for your cars. For $79 we would come out and do an AC check and tune up to make sure your system is in good shape for the summer. The only extras are any repair or refrigerant that needs to be added. And if you call us and mention you read it from the Blog you will get an extra $20 discount.

So go ahead, call us!

Tuesday, December 2, 2008

Types of Filtration for Homes - Part III

Last time we talked about the dust, pollen and small particles in the air that can cause irritation. They can generally be captured with the right type of filtering media. A sub-class of airborne irritant is bio-aerosol. Examples of that would be mold pores, air-borne viruses etc. They are airborne particulates that can cause sickness for the occupants. Depending on the specific particle size, a high MERV filter media may be able to capture some of it. However, if the occupants have low immunity, there are products available with a ultra-violet light option to kill some of the germs.

The third class of irritants is odors that come from household cleaning products, paint, smoke, pets etc. Conventional filter media will not be able to help much because the particles are too small. If it is a common problem the homeowner should consider a carbon or chemical filter to remove the odor.

It is also important to note that the two irritants above exist as symptoms of problems that occur in the house. To truly rid of the problems effort must be made to identify the source of the irritants and address it if at all possible. As a home performance contractor Sandium have the resource to place a monitoring device in your home to track the air quality over a period of time. That way we can identify the problems in a scientific way and come up with a plan to address them.

Types of Filtration for Homes - Part II

In the San Francisco Bay Area, we are blessed with some of the cleanest air in the country and probably the world. However, indoor air quality related problem such as allergy or asthma can still be a common household problem. Most people don’t realize that with proper residential air filtration that can be alleviated. Before we go into the solutions we will discuss the irritants. There are three main classes of irritants. The first and most common are small airborne particles such as dust, pollen, allergens. The second class is bio-aerosols such as mold. The third class is odors such as ones from pet or household chemicals.

MERV (Minimum Efficiency Reporting Value) is the standard in which airborne particle filtering is being measured. MERV is measured in a scale of 1 to 16 with the higher number being more efficient. Details of the scale and its relative efficiency can be found from the link below.

Most of the 1” pleated filter in the market ranges in MERV 1 to 4. They are okay for general filtration of larger particles (3-10 micron) but not effective against particles smaller then 3 micron. High efficiency whole house Media Cleaner offers the effectiveness of up to MERV 16 with the right type of filters. However, the filter medium needs to be replaced periodically for it to maintain its efficiency. Electronic Air Cleaner offers a high level of particle filtration. It has a higher first cost but a lower running cost since most can be cleaned out by the homeowner. So the decision to go with one or another depends on budget and desire for convenience. Recently there are studies that bring to question the generation of ozone, an irritant to some people, as a byproduct of some electronic air cleaner. So homeowner should select models that meet the ozone level guideline if they decide to go with electronic air cleaner.
Next time we will continue with the filtration discussion on the other types of irritants and how to combat them.

Types of Filtration for Homes - Part 1

So now that we got the filter change out of the way, we can talk about the various filtering options. The majority of homes we have in San Jose South Bay Area are fitted to use a standard 1" filter. They can be found in either the return filter grille or inside the furnace. The 1" filter also comes in a variety of flavors. There are flat filters that need to be changed on a monthly basis. They offer the minimum protection you need but they have the least air resistance. The pleated filter offers a bit higher effectiveness because of its higher surface area per square foot. Filter manufacturer also makes electro-statically charged version of the pleated filter that does a more effective job of holding the dust particles. Most of the sizes for 1" filters can be found at home improvement stores like Home Depot or Lowes.

If members of your family have allergy problems, you may want to consider some higher end filtration options. There are two main types, passive and active. Both require professional integration into your existing system. They are best installed when you are changing out your furnace or AC system. We will talk about them next time.