Category: Energy

We’ve installed the HRV system and it’s actually doing a pretty bang up job of mitigating our heat consumption, so much so that in recent weeks our motel administration block ICP has been a net exporter of renewable energy to the grid. <p><br><!–more–>

I am not happy with HRV, however, because one thing they told me would happen, didn’t happen. When the sales agent called on me, he explained to me that not only did the HRV system circulate warm air from the roof into the living area, but it also made the living area easier to warm by removing moisture from the air. <p><br>

I was interested in this idea and decided to put it to the test. How much moisture did the HRV system remove from the air? And how much would the process lead to the speeding up of heating within the living environment?<p><br>

To test this, I went out and bought a hygrometer before the HRV installation took place. A hygrometer measures the level of humidity. I also did a test during the evening to run the heater until it had caused an increase in the temperature by two degrees, and to time how long it took to do this (around 30 minutes).<p><br>

Prior to the installation, I got a humidity reading of 61. Based on my discussion with the sales rep, I was expecting the humidity to drop to between 30 and 40 post installation. I would then be able to retest the heater experiment in the reduced moisture environment and calculate how much actual time the moisture levels saved us in energy in heating the environment. <p><br>

As it turned out, the HRV system had no impact on moisture levels at all. And why would it? HRV does not dehumidify an environment; it only ventilates it. The moisture readings after the installation were the same as before, except on a couple of readings where they were slightly higher. <p><br>

Because of this, the secondary test was effectively redundant. Because HRV does not dehumidify the living environment, only ventilates it, it logically follows that energy expenditure to heat the environment would be the same prior to installation as post installation. <p><br>

So the sales rep received one very firmly worded email. I do not know whether this is an isolated incident, or a misleading marketing claim that HRV makes regularly, but it’s very disappointing, because that false claim was a core part of our decision to adopt the system. <p><br>

Apart from this infuriating lie, I so far can only recommend the HRV system. It has actually made a substantial difference to our average energy consumption at this time of year, and looks to be a good investment, despite the high-ish filter replacement costs. In particular, it reduces our energy consumption during early evening, which is a peak time where solar is not available, meaning that it has tipped the balance for our motel administration block to become a net exporter of renewable energy to the grid.