Dwyer Series Mark II 25 Molded Plastic Manometer, Inclined-Vertical Scale, 0 to 3 inH2O Measuring Range, Red Gauge Fluid, 0.826 sp. gr.

I have used Dwyer products for many years and have always been satisfied with their accuracy and quality. I'm using this manometer to monitor the air pressure drop over my premium in-line electronic air filter. The manufacturer of the air filter says it could go for up to nine months before servicing, but I never expected that kind of performance. The Dwyer manometer proves that my filter, in my application, must be serviced within 40 days or the system airflow becomes too restricted leading to excessive energy consumption. I'd rather clean the filter more often than pay extra for fuel and electricity. Looks great too! Comes with mounting screws, red indicating fluid, and tubing. You'll need to buy a pair of magnetic static tips to insert into your ductwork.

I bought this to measure the draft of my coal furnace. it functions perfect. Easy to install with great instructions. came with extra liquid in case you need to transfer it or whatever. this is three years now and works as good as the day i installed it. came with everything you need. including the fittings.

With increasing combinations of heat and smoke in our area, we upgraded our air handler to accomodate a MERV16 4" filter. The filters are about $100 each and the default suggested lifespan is one year. It needed about 20 mintues to install this manometer and discover that at one year of age our filter was causing pressure drop far below the rating of our air handler. Given that interception by filters improves as they choke, the filter is doing fine. A six month extension of filter life in our case pays for half the cost of this device. Photo indicates simplicity of installation. Two holes in ductwork for tubing port attachment, double-sided tape to mount manometer. Note that the area marked "filter" on the air handler is superseded by the larger filter housing at right (it's important to make sure manometer tubing is correctly installed on upstream downstream sides of filter).

Arrived and works as described

I am using this Manometer to allow for a visual identification of when my whole house furnace filter needs to be changed. As the filters are between $30 and $40 I do not want to change too often as I will be wasting money and if I wait too long potentially damaging my HVAC system which is less than ideal..... My current scheme is to pull the filter out and look at the color of the filter which is inaccurate to say the least, so after a recent cold snap and my furnace not operating due to a filter that needed to be changed I opted to do something about it. Competitive products seemed a little cheap to me so I went this route. As a mechanical engineer by training I was very pleased with the lab instrument quality of this Manometer, when you open yours up you will be surprised by the size of the this unit, fully 6"x6" or more. Everything that I needed to accurately measure a pressure differential was included as well as a surprise built in level for that really assisted with the installation of the product. What is extremely important about this Manometer is that the first inch of the water column is essentially more "horizontal" allowing for more accuracy in the first inch of the water column. The reason for this is that your furnace is most likely designed for about 0.5" of static external pressure. This is typically found on the HVAC systems label. So in my case when I installed the Manometer and zeroed it out with no filter in place, then added a new clean filter it measured .1" rise in the water column. That is about 20% of the total rise allowed by my HVAC units spec. (By the way that was a dead on match to the Filtrete specs for this filter, which is always nice) So I will need to change that filter when the water column reads .5" of water. Having that first inch essentially expanded out is really nice so I can see what is going on visually. Long story short, if this keeps my wife happy because her house is warm as her furnace filter was changed when it should have been then all things considered this was a great purchase. :-) Have a great day and some fun as a home geek. Jeff