Heat Recovery system issues

Rossdarragh1

Hi,

We've just completed a new build which includes heat pump and heat recovery. We've been living in the house for two months now and I'm still not 100% happy with the heat recovery.

When sleeping at night we open the window as when we woke up in the morning we felt groggy and stuffy. I gave the benefit of the doubt to the heat recovery for a number of weeks but now have to leave the window open at night.

During the hot period a couple of weeks back I opened all windows and doors to get some air into the house as the heat recovery was struggling to keep the temperatures down. I can see how this was the case as I know it's not an air conditioning system.

I'm happy to rely on opening on windows during warm spells to ventilate the house as I know the limitations of the mvhr in this regard.

However , during cooler periods when I close all opening and turn on the mvhr we don't get the same feeling of 'freshness' around the house as one would with windows open.

Perhaps the winter will be the true test of the system but at the moment I'd be inclined to turn off the system until the cold spell arrives and rely on windows being open to ventilate.

The system was installed by a reputable company and are widely used. I had the installer out , he checked the filters which he was happy with and also tested each duct to ensure an appropriate level of air was being pumped in. He was satisfied there was and to be honest gave no reasoning behind the stuffy feeling and just encouraged us to try a few more nights with all windows closed.

Anybody else with any such issues?

exaisle

Rossdarragh1 wrote: »

Hi,

We've just completed a new build

I'm wondering if the clue here is in your first few words? Is it possible that the house is still drying out and what you're getting is a drying out of all of the various compounds that go into building a house...grout..silicon..plaster...etc

I have an MHVR system but I didn't move in for at least six months after it was installed and I haven't had any such issues.

The only suggestion I'd make is to turn up the level of air being pumped to change the air in the rooms a bit more often and see if that get rid of the stuffiness...

Rossdarragh1

The drying out theory is a possibility alright. I'll give it until Christmas before I look at the issue more closely. House was pretty well dry before moving in but I guess it takes time regardless of how dry I might think it is. One thing is that the bedroom is the last opening on the ducting running along the attic. As in there is at least 2 rooms being serviced before the bedroom is serviced. Installer explained to me that it wasn't an issue as the duct reduces as it progresses and the duct within the bedroom reads that a sufficient amount of air is getting in. Would you say its wrong to have a couple of windows open with the system turned on or is that pointless.

Another thing my system has is a 'summer cooling mode'. I can't understand how this would operate though as the unit does not have a 'cooling' feature. I'd imagine this mode just slows down the system to a trickle?

mrsWhippy

Rossdarragh1 wrote: »

The drying out theory is a possibility alright. I'll give it until Christmas before I look at the issue more closely. House was pretty well dry before moving in but I guess it takes time regardless of how dry I might think it is. One thing is that the bedroom is the last opening on the ducting running along the attic. As in there is at least 2 rooms being serviced before the bedroom is serviced. Installer explained to me that it wasn't an issue as the duct reduces as it progresses and the duct within the bedroom reads that a sufficient amount of air is getting in. Would you say its wrong to have a couple of windows open with the system turned on or is that pointless.

Another thing my system has is a 'summer cooling mode'. I can't understand how this would operate though as the unit does not have a 'cooling' feature. I'd imagine this mode just slows down the system to a trickle?

I'd say this mode just turns off the Heat Recovery aspect and blows the fresh air in as is.

I wouldn't leave it until Christmas. I've heard of people getting Carbon Dioxide monitors for their bedrooms at night (off ebay) to test for this exact problem. The levels shouldn't be going over a certain amount if the ventilation is adequate. You'd have to read up about what those levels are though.

Is the system itself big enough for the size of your house? Can you provide details here?

BryanF

filters
New house
Dust

Metric Tensor

Rossdarragh1 wrote: »

Another thing my system has is a 'summer cooling mode'. I can't understand how this would operate though as the unit does not have a 'cooling' feature. I'd imagine this mode just slows down the system to a trickle?

I know of one model type that doesn't have a bypass and the "summer cooling" mode increases the speed of the inflow. The theory being that if the incoming air passes through the heat exchanger faster then it has less time and opportunity to pick up warmth from the outgoing air. So, in that case anyway, the summer cooling mode and boost mode are the same thing.

No idea if it's the case for yours though.